Nancy's Nutrition Corner


Nancy Clark, MS, RD, CSSD

Nancy Clark, MS, RD, CSSD is an internationally respected sports nutritionist, weight coach, nutrition author, and workshop leader. She is a registered dietitian (RD) who specializes in nutrition for performance, health, and the nutritional management of eating disorders. She is board certified as a specialist in sports dietietics (CSSD) and a certified WellCoach.

Nancy’s private practice is located in Newton Highlands, MA, USA. She offers one-on-one nutrition consultations to both fitness exercisers and competitive athletes, coaching them on strategies to eat wisely, enhance energy, optimize performance, and manage weight. As she is US based she will happily do virtual meetings over Skype. If nutrition is your missing link, email her at

The more renowned clients who have relied on Nancy’s sports nutrition expertise to gain a competitive edge have included members of the Boston Celtics (basketball) and Bruins (ice hockey), as well as many collegiate, elite and Olympic athletes from a variety of sports. She has been team nutritionist for the Boston Red Sox baseball team.

Nancy completed her undergraduate degree in nutrition from Simmons College in Boston, her dietetic internship at Massachusetts General Hospital, and her graduate degree in nutrition with a focus on exercise physiology from Boston University. Prior to starting her private practice, she was Director of Nutrition Services at Sports Medicine Associates in Brookline, MA.

She is a Fellow of the Academy of Nutrition and Dietetics (formerly the American Dietetic Association), the recipient of their Media Excellence Award, an active member of the Academy’s practice group of sports nutritionists (SCAN), and recipient of SCAN’s Honor Award for Excellence in Practice. Nancy is also a Fellow in the American College of Sports Medicine (ACSM) and recipient of the Honor Award from ACSM’s New England Chapter. She was awarded the American Society of Nutrition’s Media Award for her nutrition science writing.

Nancy’s contributions to runners in the Boston area culminated in her receiving the Will Cloney Award. Nancy also holds the honor of having her photo and advice on the back of the Wheaties box for their 2004 Olympic series.

Clark is the nutrition columnist for New England Runner. She is a frequent contributor to Rowing News. Clark also writes a monthly nutrition column called The Athlete’s Kitchen which appears regularly in over 100 sports and health publications and websites, including and

Nancy is the author of the best selling sports nutrition reference Nancy Clark’s Sports Nutrition Guidebook. Over 750,000 copies of this classic book have been enjoyed by health professionals and exercise enthusiasts alike. Her Food Guide for Marathoners: Tips for Everyday Champions and Food Guide for New Runners: Getting It Right From the Start help novice runners and walkers go the distance with energy to spare. And her Cyclist’s Food Guide: Fueling for the Distance (co-authored with Jenny Hegmann, MS, RD) helps both beginning and experienced cyclists optimize their performance. Food Guide for Women’s Soccer: Tips and Recipes from the Pros, co-authored with Gloria Averbuch in conjunction with Women’s Professional Soccer, helps soccer athletes have the winning edge.

Sports and nutrition are personal as well as professional interests. A member of The Greater Boston Track Club, Clark has competed at the 10 Kilometer, half marathon, and marathon distances. Clark routinely bike commutes and enjoys bike touring. She has led many extended bike tours, including a Trans america Trip and other tours through the Canadian and Colorado Rockies. She has trekked into the Himalayas and planned the high altitude menu for a successful expedition. She has personal experience with rowing (crew), yoga and HIIT. She and her husband live in the Boston area, as do her two children, now adults, who also live and work in Boston.

(click on any of the book titles to go direct to Amazon to purchase your copy)

The sixth edition of Nancy Clark’s Sports Nutrition Guidebook.

Updated and enhanced. With over 750,000 copies sold, Nancy Clark’s Sports Nutrition Guidebook has become the all-time best selling sports nutrition guide.

Recommendation from Carol Frazey, President, Fit School, Inc.

“This is the BEST nutrition book ever! A registered dietitian recommended it to me when I was running track and cross country at Penn State in the early 90’s. Now I recommend it to all of my clients. Thank you for your practical guidance all of these years. I am now 51 and still running and healthy. I attribute it all to your book!”

With Nancy Clark’s Sports Nutrition Guidebook, you’ll learn how to…

  • navigate your way healthfully through grocery stores, restaurants, social events, holidays, plus more.
  • eat well on a day-to-day basis.
  • eat well before athletic events and tournaments.
  • decipher current food, diet, and supplement options.
  • overcome food and weight obsessions.
  • lose undesired body fat while maintaining energy for exercise.

Mainly for men: strategies for how to gain weight healthfully, protein recommendations, recovery ideas, quick and easy recipes

Mainly for women: how to lose weight and have energy to exercise; how to tame the cookie monster; the health dangers of amenorrhea and how to reverse the problem; how to help your friend who struggles with food, weight & disordered eating; menopause and midlife weight gain

Because we are all getting older every day: eating plans that invest in good health and high energy; how to fuel well so you’ll enjoy exercise for the rest of your life; how to recover faster from workouts; American Heart Association’s new Dietary Guidelines.

For educators who want to use Nancy Clark’s Sports Nutrition Guidebook as their textbook: please scroll down to the end to find information on how to get a free Instructors’ Guide plus access to an image bank that contains many of the tables and charts from the new 6th edition.

Here’s some of the new information in the Sixth Edition:

Aging- ways to fight back:

Alcohol- tips for how to cut back, Anemia and iron supplementation, Arthritis, Atypical anorexia, Beer, Binge eating disorder, Carbohydrate guidelines, Clean eating, Coconut oil.

Guidlines for sugar, saturated fat, and cholesterol:
FODMAPS, Food Waste, ... etc.

Supplement update:
Nitates, glucosamine, etc., Sugar Debate, Sustainable sports diet, Testosterone and pro-hormones, Ultra-processed foods, Vegetarian and vegan options, Vitamin D, Weight -class athletes, guidelines

New Recipes: (GF = Gluten Free)
Protein-packed scrambled eggs GF, Peanut butter & dark chocolate chip muffins GF, High protein oatmeal pancakes GF, Better-for-you burger GF, Boston baked beans & rice GF, Extra creamy potatoes and cheese, Beet cherry smoothie GF, PB & J smoothie GF, Kale and cannellini bean soup GF, Chicken, kale and black bean quesadilla, Turkey chili with quinoa GF, Pumpkin chili GF, South African peanut stew GF, Chia pudding, vanilla GF, Chia pudding, strawberry GF, Banana date smoothie GF, Super seedy granola bars GF, Chocolate chip oatmeal cookies GF, Cookie dough dessert hummus GF, Chocolate cake batter dessert hummus GF.

Another worthy book by Nancy:

Food Guide for Marathoners:
An established book which is filled with practical  info for endurance runners.

You are welcome to email Nancy with general questions about her books, teaching materials, or speaking availability. She is unable to answer via email your personal questions about your eating and exercise program, weight management frustrations, or sports nutrition concerns. Those in-depth questions require an appointment.

You can find answers to many of your questions in her Sports Nutrition Guidebook; it has chapters on protein, vegetarian diets, calorie needs, weight reduction, weight gain, disordered eating, and most other topics of interest to active people.

Email her -

For Nancy's website - click HERE

Office Address:
1155 Walnut Street, Suite 21
Newton Highlands. MA 02461

Mailing Address:
PO Box 650124
West Newton MA 02465

Join Nancy's Mailing list:

To sign up to her mailing list (which isn't shared), please visit Nancy's website and add your details on her 'contact' page. Highly recommended with excellent informative blogs.

Personalized Sports Nutrition: Eating by your genes

Posted on 16-11-2021 , by: Nancy Clark

Wouldn’t it be nice if athletes could get a genetic test that tells them precisely what they should eat to enhance their performance? Of course, the answer is yes! Personalized (or precision) nutrition currently exists as a growing area of interest to athletes. Yet, the field is in its infancy. To date, precision nutrition is not precise enough to tell athletes what they can eat to be able to perform better. Plus, many factors impact performance and health, including sleep and dietary patterns. Regardless, athletes are already buying (expensive) genetic testing kits.

Speaking at the Academy of Nutrition and Dietetics annual conference (Oct 2021,, exercise physiologist David Nieman PhD, director of the Human Performance Laboratory of Appalachian State University, stated we can’t yet make claims about what to eat based on genetic testing because the results are just too variable. Plus, many factors impact performance and health, including sleep and dietary patterns. More research is needed before athletes can get valid personalized nutrition recommendations.

Without question, exercise scientists are getting better at analyzing genetics and each athlete’s metabolites (end-products of exercise metabolism). This has the potential to improve our understanding of how genes, diet, and exercise interact. But the diversity of responses leaves big gaps in knowledge.

Case in point: genes related to caffeine metabolism. Consuming 3 to 13 mg caffeine per kilogram of body weight reportedly improves athletic performance. But why do only some athletes perform better with caffeine? Is the difference due to genetics? Genetic tests can identify which athletes have the ability to metabolize caffeine quickly or slowly. But Dr. Nieman reported the data shows no patterns that reliably link caffeine-metabolizing genes to enhanced athletic performance.

Is inflammation related to genetics?

Here’s an example of how personalized nutrition could potentially help athletes. At the Western States 100-Mile Endurance Run, Dr. Nieman measured inflammation (cytokines) in 154 ultra runners. The amount of inflammation varied widely. Some runners had very high levels of cytokines and others very little. Was this due to genetics? Unknown; genetic testing couldn’t explain the differences.

Neiman has identified that exercising “on empty” creates inflammation. That is, athletes who exercise first thing in the morning without eating have an immediate spike in inflammatory cytokines. Regardless of their genetics, athletes can reduce this inflammatory response by about 40% just by consuming carb before and during extended exercise.

Does the kind of carbohydrate eaten make a difference? That is, would consuming banana or blueberries be less inflammatory than chugging a sport drink? Here’s what research tells us about the impact of carbohydrate before and during exercise:

  • Cells function best when they are fed. Both sugar from a sport drink and sugar from blueberries or banana can help cells function optimally and curb a negative stress response.
  • Polyphenol-rich fruit/fruit juice (such as blueberries, blueberry juice) curb the inflammatory response more than fruit low in polyphenols, such as banana.
  • The best dose of polyphenols from fruit is unknown. Dr. Nieman’s initial research looked at the polyphenol quercetin (found in apples). He learned very high doses of quercetin were not helpful. Nieman then tested polyphenols in amounts that athletes could easily consume. He saw better results.

For example, when athletes ate (or not) 1 cup of blueberries a day for two weeks before a 75-mile hard cycling test, the inflammatory response was much lower overall. But that said, the response varied by 14-fold among the blueberry eaters. Eight cyclists experienced high inflammation, 13 had a moderate amount, and 10 had much less inflammation. Could genetic testing help identify the athletes who responded with high inflammation? If yes, could sports dietitians encourage those athletes to eat extra blueberries to get a stronger anti-inflammatory response? We don’t know yet…

Similarly, among runners in the Western States 100-Mile Endurance Run, those who experienced a lot of muscle damage had a gene that limits their bodies’ use of choline, a nutrient that helps repair cell membranes. Could genetic testing help identify those athletes, so they could eat more choline-rich foods, such as eggs and liver? Would that help them decrease their post-exercise muscle damage, soreness, and inflammation? Stay tuned.

Inflammation creates problems for athletes. What if athletes with high inflammation could get a genetic test to determine if their exercise-induced inflammation was related to genetics? Could they then be advised to participate in, let’s say, swimming instead of ultra-running? (and would they do that?)

A multi-factorial view

Is inflammation related primarily to genetics, diet, or some other factor, like the microbiome? (Microbiome refers to the billions of bugs that live in your gut and have a strong influence on your immune system.) Dr. Nieman suspects the athletes with a robust, microbiome have less of an inflammatory response to exercise compared to athletes with a weaker microbiome. How much does genetics influence the microbiome?

We know that athletes who eat a polyphenol-rich diet (fruits, veggies) do a good job of feeding their gut microbes. They tend to have a more vibrant microbiome than those athletes who eat a diet filled with ultra-processed foods. Maybe diet is the driving force that reduces inflammation—more so than genes? We have so much to learn…

The bottom line
     Athletes vary widely in their metabolic responses to hard exercise and to the ways that food influences that response. While we do not yet know what triggers the variance (genetics? diet? the microbiome?), we do know that diet reduces inflammation (soreness, muscle damage). By regularly consuming colorful fruits (berries, cherries, apples, etc.) and colorful veggies (spinach, carrots, tomatoes, etc.), you’ll likely get more bang for your buck than spending that money on genetic testing kits that likely produce questionable nutrition recommendations. Be patient; the future of sports nutrition is just around the corner!

Sports Nutritionist Nancy Clark, MS, RD counsels both casual and competitive athletes in Newton MA (617-795-1875). Her best-selling Sports Nutrition Guidebook is a popular resource, as is her online workshop. For more information visit

Peanut Butter: Do you love it? Or fear it?

Posted on 14-10-2021 , by: Nancy Clark

“I love peanut butter but I don’t buy it. Otherwise I over-eat it.”

“Peanut butter is so fattening—but so yummy.”

“Is almond butter better healthier than peanut butter?”

Peanut butter is, without a doubt, one of the most popular sports foods around. Ask runners what they eat before a marathon, and the majority will say, “Bagel with peanut butter.” Ask cyclists what they eat during a century ride, and the answer is inevitably “Peanut butter and jelly sandwiches.” Assuming you are not allergic to peanut butter (PB), you might love it, but you also might have a love-hate relationship with this popular food. You love it so much you can easily end up eating a lot of it. You hate it because you fear it will contribute to fat gain and health problems. Hence, the goal of this article to erase the hate so you can love eating PB guilt-free, without negative consequences.

Note: Peanuts grow underground and are technically a member of the legume family, along with beans and peas. They share a nutrition profile similar with tree nuts, so we can get lump them into the same conversation. Hence, the information in this article relates to not just peanut butter but to all nut butters.

Is peanut butter fattening?
PB is not inherently fattening. If anything, people who eat peanuts, nuts, and nut butters are slimmer than nut avoiders. This fact is based on data compiled from ~576,000 people followed for, on average, about 18 years (1). Higher nut and PB intake was associated with lower body weight, a smaller waist, and weight loss. PB eaters did not have a higher BMI or percent body fat. If anything, eating PB, nuts, and nut butters seemed to have a protective effect against weight gain.

How can such a high fat food be slimming?
The warning we once heard to limit foods high in fat and calories has proven to be unwarranted. The fat in PB is satiating. A PB sandwich keeps you feeling fed for longer than, let’s say, a turkey sandwich. Having fat in each meal also makes the meal taste better. Fat carries flavor. A spoonful of yummy PB pleases the taste buds, so you’ll be less likely to go poking around the kitchen looking for something else to eat, like ice cream. This can spare you from excess calories…

Should I pour off the oil that rises to the top of the all-natural PB jar?
Pouring off the oil leaves you with a lower calorie product. If you replace those calories with, let’s say, a cookie, you are going down the wrong path. Low fat PB is less-yummy (in my humble opinion, that is) and less health-protective. Of the 14 grams of fat in a tablespoon of peanut oil, 10.5 are from “good” health-enhancing fats. Peanut oil is a source of vitamin E, an anti-oxidant that knocks down inflammation. People who eat PB, nuts, and other health-promoting oils five or more times a week have a reduced risk of heart disease and Type 2 diabetes. Why suffer through dry, less tasty, less health-protective PB when PB is not “fattening”? Storing the jar upside down can erase the oil-on-the-top issue.

Is PB better for pre-exercise fuel or post-exercise recovery?
PB, being primarily protein and fat, is a slow-to-digest fuel as compared to grains, fruits and vegetables (carbohydrates). Protein and fat take far longer to digest, so they are a poor choice for quick energy before you exercise. That said, if you will be doing a long workout that lasts for more than 1 to 1.5 hours, having PB before you exercise will offer sustained energy. It also can help buffer an influx of sugary gels and sport drinks.
After exercise, the fat and protein in the peanut butter will poorly refuel your muscles. The preferred recovery food offers three times more carbs than protein. Hence, a better choice is a PB & banana sandwich or pasta with a spicy Thai peanut butter sauce. That spoonful of PB straight from the jar will fill your tummy, but it will not rapidly refuel your muscles.

What’s the preferred type of peanut butter: organic? unsalted?
Most long-term health studies have followed typical Americans who eat PB that is processed (hydrogenated) to keep the oil from separating out. Hydrogenation can create a bad trans-fat, though the amount of trans-fat is small, less than 0.5 gram per serving. (Negligible amounts show up as 0 grams trans-fat on the Nutrition Facts label). The health benefits of any type of PB seem to outweigh any potential negatives, but in general, less processed foods (of any type) are preferable to highly processed versions.

  • Organic PB is nutritionally similar to conventional PB, but has a higher price tag, jumping from about 20 cents to about 37 cents per serving (2 Tbsp). Pesticides in PB are negligible. “They are sprayed on the ground before planting and disintegrate quickly; they have a very short half-life,” reports a Teddie PB spokesperson.
  • The amount of sodium (the part of salt attributed to high blood pressure) in Jif is 135 mg/serving, similar to the amount in a slice of bread. This is not very much sodium, given the recommended intake is 2,400 mg. sodium a day. (The “average American” consumes 3,400 mg/day). As a fit, healthy, lean athlete who likely has low blood pressure, do you need to limit your salt intake, given you lose salt in sweat? High blood pressure tends to be rooted heavily in family genetics, lack of fitness, and being overweight.
  • Is almond butter better than peanut butter?
    Almond butter is far less sustainable than PB and is far more expensive, but it is equally nourishing. The subtle nutritional differences are insignificant, in context of your entire day’s food intake. In terms of planetary health, almonds have a much higher water footprint compared to peanuts (80.4 gallons water per ounce of almonds vs 4.7 gallons for peanuts).

What about PB with flax?
Some peanut butters contain flax. Flax is among the richest sources of ALA, a plant-based omega-3 fat that is deemed anti-inflammatory and heart-healthy. A tablespoon of flax seeds offers about 2,350 mg ALA; a serving of peanut butter with flax might offer only 300 mg ALA. Given the recommended intake of ALA is about 2,000 mg/day, it seems like the addition of flax to peanut butter would have insignificant health benefits—though that depends on how much PB with flax you eat in a day!

How can I keep myself from eating too much peanut butter?
1) Prevent yourself from getting too hungry. Curbing your appetite can keep you from overeating too much of any yummy food.
2) Eat PB as often as you want. Trying to limit it contributes to binges on peanut butter-by-the-spoonful. Overeating PB typically happens before you put yourself in diet-jail, or when you flunk out of diet-jail. If you give yourself permission to enjoy PB every day, if not every meal, it will soon lose its power. Give it a try?


Nishi S., E Viguiliouk, S Blanco Mejia, et al. Are fatty nuts a weighty concern? A systematic review and meta-analysis and dose-response meta-regression of prospective chohorts and randomized controlled trials. Obesity Reviews. Sept 8, 2021 Open access

Sports Nutritionist Nancy Clark, MS.

Male Athletes & Eating Disorders

Posted on 17-09-2021 , by: Nancy Clark , in Sports Nutrition

Guys, do you know that eating disorders are not just a woman’s issue? An estimated 8% of male athletes, as compared to 33% of female athletes, have pathological eating disorders that can damage their physical and mental health. This includes anorexia, bulimia, binge eating, and compulsive exercise. Another 19% of male athletes likely have sub-clinical disordered eating behaviors. If anything, these estimates are low because eating issues in males can be challenging to identify. Many go undetected and untreated, as demonstrated by new research published earlier this year (1).

Male athletes live in an environment that can easily trigger disordered eating. Triggers include:
• immense pressure to look a certain way to perform well
• social media’s idolization of the “perfect physique”
• incessant comparison of oneself to others
• a competitive nature and drive to be better than others.

The end result: some male athletes resort to extreme behaviors in their attempt to be able to control their body shape and size. They do extra training and become extra vigilant about their food intake. It’s not uncommon for one athlete to observe another who eats restrictively and start to wonder. “If he cuts out XXX (sugar, red meat, white flour, etc.) maybe I should too…” Somehow, eliminating XXX becomes the path to becoming a better athlete—and the athlete starts down that slippery slope into a full-blown eating disorder. It can happen so easily, quickly, and unknowingly.

Social pressures:
Advertisements and social media teach men they should look lean and muscular. But no one teaches them the images are photoshopped. Or that some of the male models use performance enhancing drugs to help them look so buff. As a result, male athletes tend to suffer in silence with their concerns about their bodies, which they may perceive as “flawed.” After all, real men don’t talk about this stuff with others. Hence, they may believe they are the only ones who eat less and exercise more to fix their flaws. They may not even realize their behaviors are abnormal. Don’t all serious male athletes live on salad to be lighter, leaner, and (supposedly) better? Turns out, that is not the key to success.

Why do eating disorders take root in men in the first place?
An eating disorder gives a sense of control. While an athlete cannot control his genetics or his coach’s opinion of him, he can attempt to control his food, exercise, and weight. Given the (incorrect) belief the lighter athlete is the better athlete, competitiveness can take hold. A vulnerable male can feel compelled to do whatever it takes to reach a performance goal or a target weight. Unfortunately, one athlete’s extreme dieting can become another athlete’s motivation to become even more extreme. (“If Joe skips breakfast to lose weight, I should skip breakfast and lunch….”) The male sporting environment embraces and rewards extremes.
Extreme behaviors can bring desirable results initially – as well as praise. (“Our #1 runner is the healthiest eater on the team”) Positive comments from others are validating, confidence-boosting, and perceived as a positive sign that their efforts are paying off. That is, until the body starts falling apart. (Athlete + too much exercise + too little fuel = injuries, sooner or later)
If a male athlete hears a negative comment (such as, “Looks like you’ve gained some weight… ?”), he might feel the need to work harder and go to extremes to correct the problem. While eating less and training more might look like discipline and dedication to the sport, the extremes can destroy one’s quality of life, to say nothing of dramatically increase the odds of getting a stress fracture, tendonitis, pulled ligament, or other injury associated with underfueling and/or poor nutrition.

Seeking help:
Research confirms that few male athletes readily seek treatment for their eating disorders. They may believe they are not “sick enough” to justify getting help. They are likely unaware of the risks they are imposing on their physical and mental health. Most are unaware that their thoughts or behaviors are disordered.
Many males have no one to talk to. This leads to suffering in silence. If a male athlete does try to talk about his experience to a teammate, the teammate might express disbelief and have little understanding of what the athlete is talking about. This can lead to embarrassment and shame. It’s shameful to not only have an eating disorder—Isn’t that a woman’s issue?—but also to want a body that’s slim (not muscular, as society preaches). It’s easier to try to hide their eating disorder rather than share their personal issues.

Other male athletes don’t even know they have a problem because they have been performing well (to date) and no one seems concerned about their extreme dieting and exercise behaviors. They just get praise for how dedicated and disciplined they are. These positive comments must mean the behaviors are working and paying off (in the short term). But injuries will inevitably ruin the dreams.

In a survey of eight men with eating disorders, only four sought help—and that was when the physical and mental costs of restrictive eating outweighed the benefits. One subject reached out for help after he passed out on the side of the road during a long run. Others acknowledged the loss of sexual interest/function (side effects of under-fueling), and the heightened anxiety, depression, and extreme fatigue just weren’t worth it anymore.

What can we do to minimize eating disorders?
Male athletes need to be educated about:
• fueling wisely to enhance performance and health;
• the benefits of staying away from social media sites that focus on super-fit bodies (To compare is to despair);
• the benefits of training appropriately (not compulsively).

Coaches, trainers and sports medicine professionals also need to be educated about warning signs of eating concerns (skipping team meals, complaining about body fatness, avoiding carbs). Just like a torn ligament, an eating disorder is an injury—a mental health injury. Male athletes deserve to be able to comfortably seek help instead of suffering alone and in silence.

1) Freedman, J, S. Hage, and P. Quatromoni. Eating Disorders in Male Athletes: Factors Associated with Onset and Maintenance. J Clin Sports Psychology 2021

Sports Nutritionist Nancy Clark, MS, RD counsels both casual and competitive athletes in the Boston-area (Newton; 617-795-1875). Her Sports Nutrition Guidebook has strong sections on how to manage dieting gone awry. For more information about her book and online workshop, visit

Sports Supplements & Performance

Posted on 26-08-2021 , by: Nancy Clark

In their effort to enhance energy and optimize performance, many athletes purchase vitamins, herbs, amino acids, and other sports supplements that are reputed to offer a competitive advantage. While a few supplements (beta-alanine, creatine, caffeine, nitrates) might play a small role when added to a well-thought-out fueling plan, no amount of supplements will compensate for a lousy diet.

Fundamental to every high-performance athlete is an effective sports diet. All athletes should be taught from an early age how to optimize their performance using the food-first approach, so they know how to best fuel-up, fuel during, and refuel after challenging exercise sessions. Once an athlete has finished growing and maturing and has fine-tuned his or her fitness and performance skills, some sports supplements might be appropriately introduced with guidance from a knowledgeable professional.

That said, to the detriment of their wallets, many athletic people look for a glimmer of hope from the multi-billion-dollar supplement industry. Consulting with a registered dietitian (RD) who is board certified as a specialist in sports dietetics (CSSD) could easily be a better use of money.

Supplements are popular
A survey of Division-1 college students (89 females, 49 males) at Arizona State Univ. indicated 77% consumed at least one “claimed to be” ergogenic aid (1). Another survey of US Army personnel reports 75% used some type of dietary supplement at least once a week. Protein/amino acids were the most popular, taken by 52% of subjects (2).
Why are so many athletes willing to spend (or is that waste?) a great deal of money to buy sports supplements? The glimmer-of-hope reasons include: to improve physical appearance or physique, increase muscle mass, optimize general health, and help meet physical demands on their bodies. Unfortunately, most supplements don’t work. Before you spend your money, please educate yourself about each supplement you plan to buy.

Where to learn more
For information about (supposedly) performance-enhancing supplements, the US Dept. of Defense website Operation Supplement Safety ( offers abundant information for anyone who is curious to learn more. The website includes:

  • a list of at least 28 unsafe sports supplements to avoid.
  • a list of questions to help determine if a supplement is safe. (Does the label have a “certified safe” seal from Informed Sport or NSF? Is the label free of the words blend, matrix, proprietary, or complex? Does it make questionable claims?)
  • an A-Z index with info about specific supplements, with all you need to know about Adderall, apple cider vinegar, caffeine, creatine, energy drinks, ephedra, ketone supplements, nitric oxide, omega-3 fats, pre-workouts, pro-hormones, proprietary blends, plus many more.
  • information on unusual reactions and adverse effects (nausea, headaches, shakiness, elevated heat rate, mood change, etc.) and how to report an adverse event to the FDA and the National Institutes of Health (NIH).

Another helpful source of information is the Australian Institute for Sport’s ABCD Classification System ( The system ranks sports foods & supplements into 4 groups according to scientific evidence and practical considerations that determine whether a product is safe and if it effectively improves sports performance.

  • Group A includes specialized products with strong evidence for benefits in specific events, including sports drinks, gels, iron, caffeine, beta-alanine, bicarbonate, beet root/nitrate, and creatine, among others.
  • Group B deserves further research. It includes food compounds with anti-oxidant and anti-inflammatory properties (i.e., tart cherry juice, curcumin), vitamin C, and collagen, to name just a few.
  • Group C lacks scientific evidence to support use. These include (and are not limited to) magnesium, alpha lipoic acid, HMB, BCAAs, leucine, vitamin E–plus more.
  • Group D includes products with a high risk of leading to a positive doping test: ephedrine, DMAA, herbal stimulants, pro-hormones, hormone boosters (such as DHEA, androstenedione, Tribulus terrestris), and others.

Most supplements don’t “work”
Sports supplements that do “work” actually improve performance by just a small (but potentially valuable) amount (3), despite carefully crafted advertisements that can lead you to believe otherwise. Case in point, the popular branch-chain amino acids (BCAAs), specifically the BCAA leucine, which is known to activate the muscle-building process. Unfortunately, simply activating the process is not enough to promote muscle growth.
BCAA research indicates they do not provide any benefits above and beyond the amino acids athletes normally consume when eating protein-rich food at meals and snacks. To see any meaningful muscle-building effect, you actually need to have many other amino acids present (as happens when you eat real food, as opposed to an isolated amino acid), as well as enough calories—and of course, a good strength training program plus adequate sleep.

Varied responses
Even among supplements that “work,” the response varies greatly from person to person. Case in point, beta-alanine, a supplement used by athletes such as sprinters, rowers, and wrestlers to reduce muscular fatigue and improve endurance during high intensity exercise that lasts for 1 to 4 minutes. The varied responses can be related to not only genetics and biological factors, but also to the power of the mind, the placebo effect, adequate fuel, and enough sleep. Hence, when a supplement does “work” for some athletes, the response may be due not to the supplement—but rather to the athletes getting serious about taking better care of their bodies, eating wisely and getting enough sleep (4).
Enhancing sports performance may not need rocket science, after all?


Vento KA and FC Wardenaar. Third-party testing nutritional supplement knowledge, attitudes, and use among an NCAA I collegiate student-athlete population. Frontiers in Sports and Active Living. Sept 2020. doi: 10.3389/fspor.2020.00115
Bukhari A, A DiChiara, E Merrill, et al. Dietary supplement use in US Army personnel: A mixed-methods, survey and focus-group study examining decision making and factors associated with use. J Acad Nutr Diet 2021; 121(6):1049-1063
Maughan, R, L Burke, J Dvorak et al. IOC Consensus Statement: Dietary Supplements and the High-Performance Athlete. Int’l J Sports Nutr Exerc Metab 2018, 28:104-125
Esteves G, P Swinton, C Dale, et al. Individual participant date meta-analysis provides no evidence of intervention response variation in individuals supplementing with beat-alanine. In’tl J Sp Nutr Exerc Metab 2021; 31(4):305-31Sports Nutritionist Nancy Clark, MS, RD counsels both casual and competitive athletes in the Boston-area (Newton; 617-795-1875). Her best-selling Sports Nutrition Guidebook and her online workshop can help you eat a winning sports diet. Visit for more information.

Why Can’t I Lose Those Last Few Pounds???

Posted on 15-07-2021 , by: Nancy Clark

“I can’t lose weight like I used to. I must be eating too many carbs”
“Do you think a keto diet is a good way to drop a few pounds?”

Judging by the phone calls I get from potential clients, an increasing number of athletes of all ages are complaining, “Why can’t I do something as simple as shed a few pounds???” They are frustrated and at a loss about what to do to lose undesired body fat.
Speaking at the annual meeting of the American College of Sports Medicine (June 2021;, Kevin Hall PhD explained that fat loss is far from simple. Dr. Hall works at the National Institutes of Health. His laboratory investigates how metabolism and the brain respond to a variety of changes in diet and exercise. His research has helped identify the complex mechanisms that regulate weight.

Weight loss is not simple
You’ve likely heard, “A pound of fat equates to 3,500 stored calories. To lose one pound of body fat a week, you can simply knock off 500 calories a day—or burn off 500 calories more than usual, or some combination of the two.” Hall explained the “simple” approach to lose weight just doesn’t hold true. Chronic dieters would have shriveled up and disappeared by now. Not the case.
Weight loss is not simple math because our bodies adapt to “famines” by conserving energy. When food is scarce, be it a famine or a diet, the body conserves energy (metabolism slows, spontaneous movement lessens) and simultaneously appetite increases. Hence, eating less (dieting) takes persistent effort. The greater the energy deficit and the greater the weight loss, the greater the increase in appetite. Losing weight can becomes more and more challenging. Hence, most athletes (and people) end up unwilling or unable to sustain a diet with a calorie reduction of 25%. For a typical female athlete who maintains weight with about 2,400 calories, that’s an 1,800-calorie reducing diet. Based on my experience, athletes inevitably self-imposed a 1,200 – 1,500 calorie reducing plan. No wonder their diets fail! The stricter the diet, the hungrier the dieter, the bigger the backlash. The dieter devours way too much ice cream, too many cookies, chips…
The bottom line: Learn how to eat competently by working with a registered dietitian (RD) who specializes in sports nutrition (CSSD).

Is keto the answer?
So often I hear frustrated athletes ask, “What if I just do keto (or Paleo or another trendy diet) for a bit and then go back to eating “normally?” Ha! When dieters have managed to successfully lose weight, they can’t go back to eating like they used to eat. These dieters need fewer calories to support their lighter body. For each kilogram (2.2 lb) of weight lost, a dieter requires about 25 fewer calories less per day. Hence, dieters who lose 10 kg. (22 lb) need about 250 fewer calories per day to maintain their new reduced weight. Unfortunately, appetite-regulating hormones nudge them to want to eat more than that. This gets to be a tiring fight, and most folks lose the battle of the bulge.
The bottom line: Living in food and exercise jail to attain (or maintain) a desired physique requires a lot of energy. If life-stresses are draining your energy, you might be trying to lose weight at the wrong time in your life…

Are carbs the problem?
What if you could lose weight by cutting carbohydrates but not calories? Diet gurus have promised this for years, as do today’s keto supporters. Anti-carbers claim high-carb diets lead to excess insulin secretion, hunger, excessive eating, and fat gain. Low-carb diets are touted to reduce insulin, hunger—and promote easy fat loss.
Not so simple. Despite popular belief, simply knocking off starches (bread, pasta, grains) and sugary foods does not guarantee fat loss—unless it creates an energy deficit. That is, eliminating a serving of rice from dinner can knock off 200 calories. But does the hungry dieter then indulge in a pint of sugar-free ice cream or a keto-bomb? The carb-free = calorie-free attitude easily wipes out the deficit created by cutting out carbs.
Hall’s research does not support the carb-insulin theory that carbs are fattening. His research (1) indicates subjects in a metabolic ward who ate as much as they desired of high (75%) carb/high-glycemic diet that spiked blood glucose and led to high levels of insulin did not gain body fat. Every single subject eating the high carb/high insulin/low fat diet ate fewer calories than when they ate the low carb/low insulin keto diet with very low insulin secretion.
The bottom line: Carbs are NOT inherently fattening. (If carbs were fattening, then people in Asian countries who eat bowlfuls of rice would be obese. Not the case.)

If carbs aren’t fattening, what is?
The increase in obesity in the US correlates well with the increased intake of ultra-processed foods. Hall is pointing his finger at foods such as Oreos, soda, instant ramen noodles, chicken nuggets, etc. He has researched the impact of two weeks of an ultra-processed convenience food diet vs. two weeks of a homemade, natural foods diet. (2) The menus were very carefully designed to be equally tasty. The subjects reported no differences in pleasantness between them. They ate as much as desired.
With the ultra-processed diet, the subjects consumed ~500 more calories a day compared to the unprocessed diet. They gained weight during those two weeks—and lost weight (without trying to do so) with the unprocessed diet. Because both diets offered the same amount of sugar, carbs, and fat, those nutrients did not drive the weight change.
What’s going on? Hall is currently looking at why ultra-processed foods easily lead to weight gain.
The bottom line: Until we know more, your best bet is to limit ultra-processed foods. Fret less about sugar/carbs, and more about the processing. Somehow, find time to prepare meals. As a parent, please teach your kids to cook. Hopefully you’ll all enjoy the eat-well, stay-healthy diet!

Sports Nutritionist Nancy Clark, MS, RD counsels both casual and competitive athletes in the Boston-area (617-795-1875). Her best selling Nancy Clark’s Sports Nutrition Guidebook can help you learn to eat wisely and well. Not a book-reader? Enjoy her online workshop at

1. Hall, K. et all. Effect of a plant-based, low-fat diet versus an animal-based, ketogenic diet on ad libitum energy intake. Nat Med 2021 Feb;27(2):344-353
2. Hall, K. et al. Ultra-processed diets cause excess calorie intake and weight gain: An inpatient randomized controlled trial of ad libitum food intake. Cell Metab 2019. 30(1):67-77.

Sugar Substitutes: Good, Bad, Ugly?

Posted on 13-05-2021 , by: Nancy Clark

Today’s athletes are confronted with a plethora of foods and beverages containing low- or no-calorie sweeteners (LNCS): Diet Pepsi, Halo-Top ice cream, Gatorade Zero, Nuun. Questions arise:
Are these products a better option than their sugar-containing versions?
Will they help you lose weight?
Are they safe?
The goal of this article is not to recommend for or against LNCS sweeteners such as Equal (aspartame), Sweet ‘n Low (saccharine), and Truvia (stevia), but rather to offer science-based information to help you decide whether or not they are safe to include in your sports diet.

Background info
The 2020-2025 US Dietary Guidelines for Americans state that we should limit added sugars to less than 10% of our daily calories. The average (i.e., unfit, over-fat) American consumes about 270 calories (17 teaspoons, 13% of total calories) of added sugars a day. Soft drinks, other sweetened beverages, cookies, candy, and desserts are common culprits. For a sedentary person who may require 1,800 calories a day, 10% of calories equates to 180 calories (45 g) of added sugars a day that displace wholesome foods. Given that exercise enhances our ability to metabolize sugar, active people are less likely to end up with health issues (prediabetes, type 2 diabetes) related to sugar consumption. For them, added sugars can be a useful source of muscle fuel. Ideally, the sugar comes surrounded with nutrients, such as a post-exercise recovery chug of chocolate milk.
Today’s competitive athletes often select their foods more wisely than the “average” American. Their hope is to not only enhance performance but also reduce their risk of injury and invest in their longevity. For an athlete eating more than 3,000 calories a day, the guideline of less than 10% of total calories from added sugars equates to 300 calories (75 g) of added sugars a day. That leaves plenty of space for some sugary sports foods and treats, if desired.
Athletes’ bodies tend to readily use sugars (they appear in the blood as glucose) to replenish depleted muscle glycogen stores. During long, hard workouts, sugar-filled gels and sports drinks can enhance performance. So why would an athlete want to choose a Gatorade-Zero, Nuun, or Propel with LNCS? Well, if weight-conscious, NLCS can help athletes save a few calories (though doing so while exercising can hurt performance). With meals and snacks, swapping a can of sugar-sweetened soda for a diet soda ideally allows the athlete to enjoy 150 more calories of nutrient-dense foods, such as fruits or veggies. (We know what often happens, however. The saved calories go towards cookies. Ha!)
Are foods sweetened with LNCS a way for athletes to have their cake and eat it too? The media has certainly painted a halo of horror on LNCS, leading many to believe they are mysterious chemicals, contribute to obesity, and bolster one’s sweet-tooth. Are they really bad for you? Let’s take a look at what science says.

Aren’t they nothing but (scary) chemicals?
All foods are made of chemicals: carbon, oxygen, nitrogen. Aspartame (brand names are NutraSweet and Equal) is made of two amino acids that taste 200 times sweeter than table sugar. You need very little of it. The powder in the blue packet is mostly a harmless filler that keeps the few molecules of sweetener from getting lost in the packaging.

Are they safe to consume?
Sugar substitutes are among the most highly studied ingredients out there. The FDA, WHO and other global health organizations have confirmed the safety of these products in doses well above the amounts commonly consumed by humans. Studies which reported a link to cancer were done with animals given absurd amounts of no- or low-cal sweeteners and are not relevant to humans in real-life.
That said, the FDA has established Acceptable Daily Intakes (ADI) for these sweeteners. ADI is the amount of a LNCS a human can consume every day during their life —with a built in 100-fold safety factor below which no adverse effects have been seen. For aspartame, the ADI equates to 107 of those little blue packets a day (19 cans of diet soda every day of your life). So yes, some athletes could overshoot the ADI—but it’s highly unlikely!

Do low- and no-calorie sweeteners lead to weight loss?
LNCS are one tool in a dieter’s toolbox. They can help dieters lose weight IF they displace calories the dieter does not replace. One athlete told me he lost 30 pounds in a year just by trading in his lunch- and dinner-time can of Pepsi for Diet Pepsi. That one simple change shaved off 300 calories a day that he did not replace. That said, research indicates people can easily compensate for the calories by eating more of other foods…

Do low- and no-calorie sweeteners lead to weight gain?
No. People who drink diet soda are more likely to be over-weight, but diet soda did not cause the weight gain. Rather, people who live in large bodies are more likely to use LNCS to save some calories.

Don’t these sweeteners trick the body into thinking it’s getting sugar—and trigger a spike in blood glucose, followed by a crash, and hunger?
Well controlled, randomized studies indicate the answer is no. Nor do LNCS make people feel hungrier. Some animal studies have shown that LNLCS might increase appetite, but those studies were conducted with large amounts of LNCS that we would never consume. This has not been replicated in humans.

Do no- or low-cal sweeteners have a negative impact on the microbiome?
Questionable research with mice who consumed very large amounts of saccharin suggests it might impact the microbiome of rodents. But no conclusive evidence to date indicates LNCS negatively impact the human gut microbiome. Stay tuned.

The bottom line
We are all born with an innate desire for sweet tastes, starting with breastmilk! We have many options for satisfying that sweet tooth in good health.

For more information:
Joan Salge Blake RD PhD with Hope Warshaw RD, Certified Diabetes Educator

Laviada-Molina H, Molina-Segui F, Pe ́rez-Gaxiola G, et al. Effects of nonnutritive sweeteners on body weight and BMI in diverse clinical contexts: systematic review and meta-analysis. Obes Rev 2020; 21:e13020

Position of the Academy of Nutrition and Dietetics: Use of Nutritive and Nonnutritive Sweeteners

Sports Nutritionist Nancy Clark, MS, RD counsels both casual and competitive athletes in the Boston-area (Newton; 617-795-1875). The 6th edition of her Sports Nutrition Guidebook (2020) can help you eat to win. For more information, visit

What about canola oil?

Posted on 22-04-2021 , by: Nancy Clark

The two main types of dietary fat are:

saturated fat (mostly from animal sources; hard at room temperature)
unsaturated fat (mostly from plant and fish sources; oil at room temperature).

The Dietary Guidelines for Americans recommend we limit the hard saturated fats as are they associated with heart disease. Unsaturated fats, which include mono- and polyunsaturated fats, are considered beneficial because they can help lower the “bad” LDL cholesterol and therefore reduce the risk of heart disease.

When it comes to consuming unsaturated fats, the Dietary Guidelines for Americans recommends we consume plant oils, such as canola, corn, olive, peanut, safflower, soybean, and sunflower. Other plant-sources of oils include nuts, seeds, olives, and avocados. Fish and other seafood are important for omega-3 oils.

What About Canola Oil?
Canola oil, derived from the rapeseed plant, is a plant-based oil with a favorable nutrition profile. It has the least amount of saturated fat (7%) compared to other oils (including olive) and the most omega-3 fatty acids (19%). It is also a good source of vitamins E and K. It has a neutral flavor that is ideal when baking, as well as for sautéing, stir-frying, or grilling.

Smoke Point
An oil’s smoke point (burning point) depends on the type of oil and its chemical composition. Some oils such as extra virgin olive oil and coconut oil have low smoke points ranging from 325-375°F while the smoke point of oils such as canola, peanut, and corn oil range from 400-450°F. No matter what oil you choose to cook with, you want to avoid overheating and burning it to retain the best taste and to avoid damaging the heart healthy fatty acids contained in the oil.

You might have heard that when oils are heated, they release harmful toxins and trigger inflammation. While studies show that oils release harmful by-products when heated for long amounts of time at extremely high temperatures, this is not representative of normal kitchen cooking practices. Moreover, the link between possible unhealthy compounds and effects on health is largely dependent on dose. For instance, recipes typically call for 2 tablespoons or less of oil when sautéing, which is an extremely small dose when split among 4-6 servings.

In a study published in The American Journal of Clinical Nutrition, researchers assessed the association between consumption of partially hydrogenated vegetable oils (partially “hardened” and containing higher saturated fat), natural vegetable oils, and inflammatory markers in the blood among women. They found that higher intakes of natural vegetable oils—canola oil, corn oil, sunflower oil, soybean oil, and olive oil—were associated with lower concentrations of inflammatory biomarkers, whereas the processed fats (soft or hard margarines and shortening) were associated with higher concentrations of these biomarkers.

In addition, the Journal of the Academy of Nutrition and Dietetics published a systematic review of 15 randomized controlled trials (regarded as the gold standard for scientific evidence) which assessed the effect of dietary linoleic acid (a type of polyunsaturated fat common in vegetable oils) on inflammation in healthy individuals. Virtually no evidence showed that adding linoleic-rich vegetable oils to the diet increase the concentration of inflammatory markers. Oils that are highest in linoleic acid (aka polyunsaturated fat) include canola, peanut, soybean, grapeseed, and sunflower oil. You might be surprised to learn that canola oil contains more polyunsaturated fat than olive oil (4 grams in 1 tbsp of canola oil versus 1.5 grams in 1 tbsp of olive oil). Both are great choices and serve an important role in a healthy diet.

The Bottom Line
Dietary fat can be a positive part of a well-balanced and health-promoting diet. Insufficient evidence supports the claim that plant oils cause inflammation. That said, you do want to focus your attention on unsaturated fat from olive, peanut, and canola oils, as well as avocado, nuts, seeds, and fish. These health-promoting fats help increase satiety, lower cholesterol levels, and support heart health.

When it comes to the confusion around canola oil, rest assured it is safe, health-promoting, and non-inflammatory. Just like in all aspects of the diet, you want to have variety in the types of oils you use to cook and the types of fat sources you consume. Instead of obsessing over the exact breakdown of the poly-, monounsaturated, and saturated fat contents of the oil, try thinking of its flavor profile when determining which one to use. For example, the neutral flavor of canola oil is often the preferred choice when baking. A peanut or sesame oil is tasty if you are making a stir-fry, as is olive oil in a Mediterranean inspired dish. The bottom line is that when it comes to fat, try your best to keep it plant-sourced!


2015-2020 Dietary Guidelines for Americans

Dietary fats. (n.d.). www.Heart.Org.

Edelstein, Sari. (2018). Food Science: An Ecological Approach: Vol. Second edition. Jones & Bartlett Learning.

Esmaillzadeh, A., & Azadbakht, L. (2008). Home use of vegetable oils, markers of systemic inflammation, and endothelial dysfunction among women. The American Journal of Clinical Nutrition, 88(4), 913–921.

Guillaume C., et al. “Evaluation of Chemical and Physical Changes in Different Commercial Oils during Heating”. Acta Scientific Nutritional Health 2.6 (2018): 02-11.

Johnson, G. H., & Fritsche, K. (2012). Effect of Dietary linoleic acid on markers of inflammation in Healthy Persons: A Systematic Review of Randomized Controlled Rrials. Journal of the Academy of Nutrition and Dietetics, 112(7), 1029-1041.e15.

U.S. Canola Association. Retrieved April 15, 2021, from

Written by guest blogger Emily Stewart, nutrition student at Simmons University and aspiring sports dietitian.

The ABC’s of Sports Nutrition

Posted on 13-01-2021 , by: Nancy Clark

Believe it or not, eating a good sports diet can be simple. Yet too many athletes have created a complex and confusing eating program with good and bad foods, lots of rules, and plenty of guilt. Let’s get back to the basics and enjoy performance-enhancing fueling with these simple ABC’s for winning nutrition.

Appreciate the power of food and the positive impact it has on athletic performance. Also notice the negative impact of hunger on your mood, ability to focus, and energy. As an athlete, you are either fueling up or refueling. Every meal and snack has a purpose; be responsible!

Breakfast: eat it within three hours of waking for a high-energy day. If you are not hungry in the morning, trade evening snacks with little nutritional value for a wholesome morning meal. Alternatively, eat that wholesome morning meal at night, in place of the snacky foods.

Carbohydrates are the preferred source of muscle fuel for hard exercise. Do not “stay away from” pasta, potato, bread, bagels and other starchy foods that have wrongly been deemed fattening but actually help keep muscles well fueled. Serious athletes who minimize carb intake risk having poorly fueled muscles.

Dehydration needlessly slows you down, so plan to drink extra fluid 45 to 90 minutes before a hard workout. That’s how much time the kidneys require to process fluid. Schedule time to tank up, urinate the excess, and then drink again soon before you start to exercise.

Energy bars are more about convenience than necessity. Bananas, raisins, Fig Newtons and granola bars offer convenient fuel at a fraction of the price. If you prefer pre-wrapped bars, choose ones made with wholesome ingredients such as dried fruits, nuts, and whole grains.

Foods fortified with iron can help non-meat eaters and vegetarians reduce their risk of becoming anemic. Iron-fortified breakfast cereals, such as raisin bran, Grape-Nuts and Wheaties offer more iron than all-natural brands with no added iron, such as Kashi, old-fashioned oats, and granola.

Gatorade and other sports drinks are designed to be used by athletes during extended exercise, not as a mealtime beverage or snack. Most foods contain far more electrolytes than in sports drinks.

Hypoglycemia (low blood sugar, as characterized by light-headedness, fatigue, and inability to concentrate) is preventable. To eliminate 4:00 p.m. low blood sugar, enjoy a hearty mid-afternoon snack.

Intermittent fasting might offer health benefits for an overfat, under-fit, sedentary person, but it is not designed for athletes. Extended time without food puts your body into muscle-breakdown mode.

Junk food can fit into your sports diet in small amounts. That is, you don’t have to have a “perfect diet” to have an excellent diet. The goal is 90% quality foods and, if desired, 10% fun foods.

Keto, Paleo and other fad reducing diets “work” because they limit calorie intake. But when dieters escape from food-jail, backlash takes its toll. Your better bet: Learn how to eat appropriately, not diet restrictively.

Lifting weights is key to building muscles. Carbohydrates provide the energy needed to lift heavy weights. To support muscular growth, choose carbohydrate-based meals with a side of protein, as opposed to protein-based meals with minimal carbs.

Muscles store carbohydrate (grains, fruits, veggies) as glycogen. When replenishing depleted glycogen to prevent needless fatigue, muscles store about store about 3 ounces of water with each one ounce of carb. Hence, an athlete might gain 2 to 4 pounds of (water) weight when refueling on a rest day.

Nutrient-dense whole foods are so much better for your health than ultra-processed foods. By satiating your appetite with hearty breakfasts and lunches, you’ll curb your desire for afternoon and evening chips, cookies, instant meals, and other highly processed foods—and may not even miss them!

Obsessed about food and weight? If you spend too much time thinking about what or what not to eat, meeting with a sports dietitian (RD CSSD) can help you stop the struggle. Eating should be simple.

Protein is an important part of a sports diet; it helps build and repair muscles after hard workouts—but it does not refuel muscles. A recovery drink should offer three times more carbs than protein. Choose a fruit smoothie (made with Greek yogurt) instead of a low-carb protein shake.

Quality nutrition is best found in natural foods. Be sure there are more apple cores and banana peels than energy bar wrappers and ultra-processed food packages in your waste basket.

Rest is an important part of a training program; your muscles need time to heal and refuel. Plan one or two days with little or no exercise per week. Expect to feel just as hungry on rest days as on exercise days; your muscles need food to replenish depleted glycogen stores.

Sweet cravings are a sign you’ve gotten too hungry. Experiment with eating enough breakfast and lunch to feel satiated; don’t stop eating just because you think you should. You’ll have more energy in the afternoon, better workouts—and far less desire for sweets and treats later in the day.

Thinner does not equate to performing better if the cost of being thinner is skimpy meals and poorly fueled muscles. Initially a lighter athlete might set some PRs, but stress fractures and injuries will ultimately take a toll. The better bet: focus on being well-fueled and powerful.

Urine that is dark colored and smelly indicates a need to drink more fluid (this includes coffee, yogurt and watery foods). Well hydrated athletes have pale-colored urine and urinate every 2 to 4 hours.

Vegetarian and vegan athletes should include plant-protein at each meal and snack. Peanut butter on a bagel, hummus with pita, and beans in chili are just a few suggestions.

Weight is more than a matter of will power; genetics plays a role. The apple doesn’t fall too far from the tree. Forcing your body to be too thin is abusive.

Xtra vitamins are best found the all-natural way: in dark colorful vegetables such as broccoli, spinach, peppers, tomatoes and carrots, or in fresh fruits such as oranges, grapefruit, cantaloupe, strawberries and kiwi. Chow down!

Yes, even you can optimally fuel your engines. The trick is to prevent hunger. When too hungry, you’ll likely grab the handiest (but not the healthiest) food around. Experiment with front-loading your calories.

Zippy and zingy–that’s how you’ll feel when you fuel with premium nutrition. Eat well and enjoy your high energy!

For personalized nutrition help, consult with a registered dietitian (RD) who is a board certified specialist in sports dietetics (CSSD). Use the referral network at to find your local food coach.

Nancy Clark, MS, RD, CSSD (Board Certified Specialist in Sports Dietetics) counsels both casual and competitive athletes in her private practice in Newton, MA (617-795-1875).

Hot Weather Hydration Tips

Posted on 11-08-2020 , by: Nancy Clark

Steaming hot summers bring up nutrition questions for athletes who are training and competing in the heat:

  • How can I tell if I’ve had enough to drink?
  • Should I be consuming extra electrolytes?
  • Is it possible to drink too much?”

With summers getting hotter and longer, here are some practical hot weather sports nutrition tips.

To start, let’s look at the physiology of keeping the body cool. Normal body temperature is 98.6°F (37°C). When you exercise, your body temperature increases. At 104°, you are in the danger zone. If you were to really overheat and get to 107.6°F (42° C), your cells would get damaged –similar to how raw egg white coagulates as it starts to cook. You don’t want that to happen!

  • To dissipate the heat generated by working muscles, blood flow to the skin increases and your sweat glands get activated. As sweat evaporates from the skin, it provides a cooling effect.
  • With repeated training in the heat for more than an hour a day, the body acclimatizes over the course of 7 to 14 days. You’ll notice greater exercise capacity. In one study, endurance increased from 48 to 80 minutes.
  • The more you train in the heat, the more you sweat. While this helps keep you cooler, the additional fluid loss can easily lead to progressive dehydration if you do not fully replace sweat losses on a daily basis.
  • Sweat losses of 2 to 3 pounds per hour are common among athletes who exercise vigorously in the heat; some lose more than that. You don’t need to replace every drop of sweat, but you do want to minimize losses, so you end up losing less than 2% of your body weight (3 pounds for a 150-pound athlete).
  • “Drinking to thirst” generally works for day to day living and fitness exercisers, but not always for athletes. Studies suggest drinking to thirst often results in body water deficits of 2% to 3% among athletes who sweat heavily in the heat. That level of dehydration impairs athletic performance. Hence, ironman Triathletes, marathoners, and other endurance athletes should have a drinking plan that balances losses with intake.
  • To learn how much sweat you lose during exercise, weigh yourself nude before and after a hard workout, accounting for any fluid consumed during the session. If you have lost, let’s say 2 pounds per hour (32 ounces, 1 quart), target drinking 6 to 8 ounces every 15 minutes the next time you exercise at that intensity and under those weather conditions. Practice drinking that volume of fluid, to train your gut to handle it comfortably.
  • Monitor progressive under-hydration by taking daily weights first thing in the morning. A downward weight trend can be a warning sign of inadequate fluid replacement, particularly if the morning urine is dark and concentrated. (Yes, it could also reflect fat-loss.)
  • You can tell if you have adequately rehydrated by monitoring the color and volume of your urine—as well as how often you need to urinate. For example, if you sweat heavily during your workout and then don’t pee for five hours afterwards, you are underhydrated. Urine that is dark and concentrated is another warning sign.
  • On a daily basis, your goal is void a significant volume of urine that looks like lemonade, not beer, every 2 to 4 hours. Google urine color chart for a visual resource.
  • When you sweat, you lose not only water but also electrically charged minerals (electrolytes), more commonly known as sodium, calcium, magnesium, and potassium. Sodium (a part of salt) is the main electrolyte of concern.
  • Because you sweat off proportionately more water than sodium, the concentration of sodium in blood actually increases during exercise. In standard (i.e., not extreme) exercise situations, replacement with electrolyte supplements is needless; food eaten at meals/snacks offers ample electrolytes.
  • The primary purpose of sodium in a sports drink is to enhance fluid absorption and retention, as well as enhance absorption of carbohydrate. The amount is inadequate to replace sodium lost in sweat. For example, a slice of bread offers about 125-200 mg sodium; 8-oz. Gatorade offers only 110 mg.. Gatorade Endurance formula, 200 mg.
  • If you will be exercising for hours on end in the heat (i.e., all-day bike ride, ultra-run, or tennis tournament), you can lose a significant amount of sodium. Assuming you will be consuming food during the extended exercise session, you can replenish lost sodium with peanut butter & jelly sandwiches (500 mg sodium), thin pretzels (490 mg/1-oz) and cheese sticks (200 mg/stick).
  • Caution: Do not over-consume plain water and/or sports drink during extended exercise unless you are taking in other sources of sodium. Excess water dilutes the reduced amount of sodium in the blood and can lead to hyponatremia (low blood sodium), a life-threatening condition that can result in death. This can happen, for example, with slower (>4-hour) marathoners who diligently drink at every water station, regardless of thirst.
  • After exercise, if you need sodium, you will crave salt and should honor those salt cravings with crackers and cheese, pickles, pizza, potato chips, V-8 Juice—or more simply, sprinkle salt on your recovery meal.
  • Most healthy, sweaty athletes can set aside public health guidelines to “limit your salt intake.” Replacing sodium losses is important to rebalance your body.
  • When you know you will be sweating for more than an hour or two in the heat, plan to boost your pre-exercise salt intake. By consuming 300 to 500 mg sodium before you exercise, the sodium will already be in your body, working to retain water and retard dehydration. During extended exercise, plan to target 500 to 700 mg sodium per hour (and more if you experience muscle cramps).
  • Chocolate milk is preferable to sports drink to enhance rehydration. It offers more sodium (150 mg vs 110/ 8 oz) —as well as more carbohydrate (to replenish glycogen stores) and protein (to repair muscles). Drink wisely!

For more information, refer to Nancy Clark’s Sports Nutrition Guidebook


Consensus recommendations on training and competing in the heat. British Journal of Sports Medicine 2015, 49(18): 1164-1173

Practical Hydration Solutions for Sports. Nutrients 2019; 11(7):1550

Considerations when building a vegan sports diet

Posted on 13-06-2020 , by: Nancy Clark

Vegan and vegetarian diets are here to stay; they are not a passing fad. The busy lifestyle of vegan athletes can create nutrition challenges. For example, when eating on the run, vegans may find Oreos are more readily available than, let’s say, roasted chickpeas. Grab-and-go snacks of just a bagel or a banana should get balanced with some protein — but is hummus or soymilk readily available? All this means vegan athletes have to be responsible and plan ahead.

When listening to my vegan/vegetarian clients, I often hear “red flag” statements that signal misinformation. Let’s take a look at some common misconceptions and correct some myths related to vegan/vegetarian sports diets.

“Carbs” are fattening, a waste of calories? False!
Plants are carbs! While you want to limit nutrient-poor carbs (like Frosted Flakes, Pop-Tarts, ramen), wholesome carbs (preferably called grain-foods) should be the foundation of every meal to fully fuel muscles. Athletes who train one to three hours a day can easily end up with needless fatigue if they try to thrive on fruit and salads. Grains (and all “carbs”) are NOT inherently fattening. Excess calories of any food can be fattening.
As a vegan/vegetarian athlete, you would be wise to eat grains (such as oatmeal, whole wheat bread, brown rice) as the foundation of each meal/snack. Combine them with a colorful assortment of fruits and/or vegetables for more muscle-fuel, and of course, a dose of protein.

Lunchtime salads are a healthy vegan meal? Sometimes.
While salads can be nutrient-rich, they can also be protein and carb-poor—but high in calories given a “little bit” of olive oil on a big salad ends up being a lot of dressing. Filling up on calories from fat will not refuel depleted muscle glycogen. Vegan athletes could better refuel their muscles with a grain-protein combination such as a hummus wrap or beans and rice.

Quinoa can be the “protein” in a vegan meal? No!
Quinoa is reputed to be a protein-rich grain, containing all the essential amino acids needed to build muscle. It is not a stand-along protein-rich food. If you compare quinoa to other grains, you’ll see it offers only 6 grams of protein per 200 calories, similar to rice (4 g), and less than pasta (7 g). Most athletes should target 15 to 25 grams of protein at each meal. That means, you want to add more than just quinoa to your salad. How about tofu? beans? lentils?

Almond milk is a replacement for dairy milk? No way!
Almond juice (it is not milk) has far fewer nutrients than dairy milk. Milk’s 8 grams of high-quality protein is life-sustaining. The 1 gram of low-quality protein in almond beverages is not. Soy or pea milk are acceptable dairy-free alternatives to cows’ milk.

Soy causes cancer and man-boobs? Wrong.
The latest research indicates soy is cancer preventive and is safe— even for women with breast cancer. As for man-boobs, the one case study about unusual male breast development refers to a person who routinely drank three quarts of soymilk a day. That is a LOT of soymilk. For the latest soy updates, enjoy this podcast:

Protein bars and powders can replace real foods? Not really.
Protein-rich foods are preferable to highly processed bars and shakes. Nutrients in natural foods interact synergistically Instead of yet-another bar or shake for a meal or snack, how about cereal + (soy) milk, crackers + hummus, or banana + nut butter? Aren’t these real foods more in keeping with the spirit of veganism?

For more information: Nancy Clark’s Sports Nutrition Guidebook, 6th edition (2019)

Protein, Plant-based Diets & Athletes

Posted on 30-03-2020 , by: Nancy Clark

From social media to television shows, we are constantly bombarded with mixed messages about protein. No wonder many athletes struggle over how to consume the best sports diet. They want to know: Should it include—or exclude—meat, fish, poultry, eggs, and dairy? For vegetarian athletes, the answer is simple: animal foods are on the “no” list. For Paleo fans (carnivores), the answer is also simple: meat is important.

Let’s take a look at the science and what we know. Protein helps build muscle in conjunction with regular resistance training. Is a protein-focussed diet best? NO. Simply eating more protein will not give you bigger, stronger muscles. You need to combine protein with strength training, a well balanced diet, and consistent fueling and re-fueling of your muscles.

Protein drinks, shakes, bars, powders are all around us, but the truth is the most easily accessible protein sources are whole foods. Animal protein sources, such as lean meats and poultry, as well as dairy products (think cheese and yogurt) provide us with all of the essential amino acids (building blocks), and plenty of them. Plant-based diets can also provide the protein and amino acids you need. Consuming a variety of beans, nuts, seeds, quinoa, tofu, and especially soy products, will give you the tools used to build strong muscles.

Athletes typically need about 0.5 to 0.8 grams of protein for each pound of body weight. So, for example, a 150-lb (68-kg) athlete will need approximately 75 to 120 grams of protein per day. For this athlete, eating a small 4-ounce baked chicken breast will get them 35 grams of protein. And that is just for one meal and from one food. Add in foods from other meals—yogurt, beans, peanut butter, and hummus—and you are easily set for the day.

We live in a country where protein is abundant. According to Dr. David Katz, MD, MPH, a board-certified specialist in Preventive Medicine/Public Health, a shift towards more plant based proteins will move us in a healthier direction, but it’s not all or nothing. We want to focus on choosing an overall wholesome diet with foods that contain a variety of proteins, as well as high-quality carbohydrates, fats, vitamins and minerals. By eating a variety of nutrient-rich foods throughout the day, you can invest in good health, be you an athlete who eats lean meat-meat, plant proteins, or both.

The world of protein is not as complicated as the world has made it out to be. If you are unsure of where to begin or are questioning your protein needs, you need not go it alone. You can consult with a registered dietitian (RD) who is a board certified specialist in sports nutrition (CSSD) near you. ( Alternatively, Nancy’s Clarks Sports Nutrition Guidebook explains the in’s and outs of protein quality and needs for athletes in an easy to understand, practical way.

Written by guest blogger and Simmons University nutrition student Ali Mattia ATC.

Granola! A recipe for homemade happiness

Posted on 19-03-2020 , by: Nancy Clark

What Can’t Granola Do? Granola is such a universal food product; it can be incorporated into your diet in so many different ways! Breakfast, lunch, dinner, or a snack, you name it and granola can be a part of that meal.

Several ways you can incorporate granola into your breakfast includes eating it as a cereal, sprinkling it over yogurt, mixing it into oatmeal, using it to top açai bowls, and using it to add crunch to pancakes.

As for lunches, you can add granola to your salads to add a nutty crunchy factor to your greens, and you can use it to bread your chicken when you’re making homemade chicken fingers.

Regarding dinner, you might think granola would be a strange addition to your meal, but it actually can compliment many different dishes. Granola can be a topping to roasted vegetables to add a nutty crunchy aspect, and any recipe with breadcrumbs can be substituted with granola (meatloaf, baked chicken, casseroles, meatballs, etc.).

Granola easily integrates into dessert. Replace a streusel topping with granola, and sprinkle granola on top of frozen yogurt. The options are endless, reinforcing the fact that granola is a universal food product.

The honey nut granola is one of many sport food recipes from Nancy Clark’s Sports Nutrition Guidebook.

Recipe for Honey Nut Granola

The honey nut granola is easy to make.The recipe is flexible, so don’t hesitate to design it to your own liking: add your favorite nuts, seeds, and dried fruits (dates, apricots, figs, bananas, raisins, etc.).

The uniqueness of this honey nut granola recipe is including powdered milk for added protein. If you’re not familiar with powdered milk (found in the cooking section at grocery stores), it’s one of the best (and least expensive) protein powders around.


3 cups (240g) rolled oats (not instant oatmeal)
1 cup (120g) chopped almonds (or other nut)
2 teaspoons cinnamon
1 cup (120g) powdered milk
1/3 cup (115g) honey
1/3 (80ml) canola oil
1 cup (160g) dried fruit bits (e.g., raisins, dried cranberries, chopped dates)

Optional: 1 teaspoon salt, 1/2 cup (60g) sesame seeds (untoasted), 1/2 cup (60g) sunflower seeds (unsalted, untoasted), 1/2 cup (60g) wheat germ, 1/2 cup (80g) ground flax seed


In a large bowl, combine the oats, almonds, cinnamon, and powdered milk (and salt, sesame seeds, and sunflower seeds, as desired).
In a saucepan or microwavable bowl, combine the honey and oil. Heat until almost boiling Pour honey mixture over the oat mixture and stir well.
Spread the mixture onto two large baking sheets.
Bake at 300 degrees Fahrenheit for 20-25 minutes, stirring every 5 minutes.
After the granola has cooled, add the dried fruit (and wheat germ and flaxseed, as desired). Store in an airtight container

Yield: 10 1/2- cup servings

Nutrition information: 3,300 total calories; 330 calories per 1/2 cup; 40 g carbohydrate; 10 g protein; 14 g fat

Blog and photo courtesy of Simmons University nutrition student Amber Nobbs.

Fueling during exercise: how to enjoy long workouts

Posted on 06-01-2014 , by: Nancy Clark

Do you have an upcoming marathon, century bike ride, triathlon, tennis tournament or other endurance event?Perhaps you feel confused about how to maintain energy during extended exercise sessions?

This handy guide can help you figure out your calorie targets. Because your body’s response to food during exercise is unique to you, please experiment during training, observe the benefits (or costs), and tweak accordingly!

Exercise duration: :   Less than 45-60 minutes

Carbohydrate intake during exercise: nothing other than pre-exercise snack

Examples:   A pre-exercise meal (oatmeal) or snack (banana) will do the job to keep you adequately fueled during the workout

Exercise duration:   1-2.5 hours

Carbohydrate intake during exercise:   30 to 60 grams carb/hour

Examples:   Consume 120 to 240 calories of carbs in the form of sports drinks, gummy candy, gels, dried pineapple, banana, and other commercial or standard foods

Exercise duration:  More than 2.5 hours

Carbohydrate intake during exercise:   60 to 90 grams carb/hour

Examples:   For long events like extended training for a 100 mile bike ride, Ironman triathlon, or trail run, target 240 to 360 calories per hour from a variety of carbohydrates including fruit, gummy candy, and granola bars, as tolerated.To avoid “flavor fatigue”, include not only sugary sweets (sports drinks, candies and gels)  but also peanut butter and honey sandwiches, beef jerky, pretzels, chicken broth, cheese sticks, and other foods that offer savory and salty flavors. Be sure to experiment during training to figure out what you can tolerate!

For more information: Nancy Clark’s Sports Nutrition Guidebook, Food Guide for Marathoners, or Cyclist’s Food Guide.

Should you eat less on rest days?

Posted on 24-11-2013 , by: Nancy Clark

Nancy, here’s a question for you. Should my calorie intake fluctuate based on how much training I’m doing?  I usually do between 90 and 120 minutes a day, but sometimes I might do just a 45-minute workout.  Do I cut my calorie count proportionally?


On days when you are doing less exercise you will likely want to eat just as much (or almost as much) because—

1) Your muscles are using any extra unburned calories to refuel your depleted glycogen stores from the previous days’ tiring workouts, and

2) You may be more active during the rest of your “light exercise” days. That is, observe if on your light days or rest days you decide to mow the lawn, vacuum the house, wash your car, and do lots of errands. That extra activity counts!

Your best bet is to listen to your body; it is your best calorie counter. If you are thinking about food and fighting the urge to eat, your body is saying it needs more fuel. When you eat something to resolve that hunger, observe if you–

–feel better,

–stop obsessing about food, and

–have interest in doing something other than fight off urges to eat.

I generally eat just as much on rest days. Sometimes by dinner I am not as hungry, so I eat a lighter dinner just because I don’t want a heavy meal. I listen to my body and trust it can regulate an appropriate food intake. Perhaps you can experiment and observe ithat your body can also naturally regulate a proper intake? (It that seems too hard, you might want to meet with a sports dietitian who can help you eat intuitively. Use the referral network at

For more information:

The recovery chapter in Nancy Clark’s Sports Nutrition Guidebook (2019)

Caffeine for Sports Performance

Posted on 01-03-2014 , by: Nancy Clark

For athletes, caffeine is a proven performance enhancer. In their new book Caffeine for Sports Performance, sports dietitians Louise Burke and Ben Desbrow and exercise physiologist Lawrence Spriet address all-things-caffeine that an athlete might want to know.

Here are just a few tidbits that I gleaned from this comprehensive resource. Perhaps the information will help you add a little bit of zip to your workouts.

Note: No amount of caffeine will compensate for a lousy diet. If you choose to use caffeinated products to enhance your sports performance, make sure you are also fueling wisely!

• A cup of pre-exercise coffee can help most athletes work harder—without realizing it. Caffeine has been shown to enhance performance by about 1% to 3%, particularly in endurance sports. For example, cyclists who consumed caffeine prior to a 24-mile (40-km) time-trial generated 3.5% more power than when they did the ride without caffeine.

• Athletes vary in their responsiveness to caffeine, from highly effective to negative. Some of the side effects associated with too much caffeine include higher heart rate, anxiety, “coffee stomach”, irritability, and insomnia.

• The recommended performance-enhancing dose of caffeine is about 1.5 mg/lb (3 mg/kg) body weight. This can be consumed 1 hour before the event, and/or during the event (such as a caffeinated gel or defizzed cola every hour). For example, triathletes commonly consume caffeinated gels before each segment, to distribute the caffeine throughout the event rather than have a big pre-race jolt that might make them feel shaky and unable to concentrate. Some athletes delay caffeine intake until fatigue starts to appear, and then they ingest 0.5-1 mg/lb (1-2 mg/kg) body weight.

• Caffeine’s ergogenic effect maxes out at about 200 to 250 mg caffeine. (This is much less than previously recommended.) More is not better.  Experiment during training to learn what amount (if any) works best for your body!