Sports Nutrition Updates from ACSM

by Nancy Clark, MS, RD, CSSD

At the 2023 American College of Sports Medicine Annual Meeting (ACSM;, more than 3,000 sports medicine professionals and researchers from around the globe gathered to share knowledge. Several sports nutrition presentations offered updates that might be of interest you. Here are summaries from a few of those presentations.

Body Composition:
Historically, collegiate and professional runners would routinely have their body fat measured, with the data posted for all to see. Many were praised for their extreme leanness (read anorexia); others were fat-shamed. Hence, many runners experienced intense pressure both internally and externally to have a lean physique.

• Today, we know that athletic performance is not dictated primarily by a runner’s percent body fat but rather by volume of training, mental state, adequacy of sleep, and sufficient food intake—among other factors.

• Today’s recommendations state measurement of body fat should only be done if 1) the runner consents, 2) the measurement is done in private by a trained measurer using the most reliable method, 3) the information is discussed in confidence with the runner and their health care team, and 4) the mental and physical health of the runner is top priority.

• Runners, please understand you will perform better if you focus on getting stronger and gaining power, as opposed to restricting food. If the cost of losing body fat is having to train for weeks with poorly fueled muscles, your performance will suffer and your risk of injuries will increase.

Ultra-Processed Foods and Athletes

About 95% of athletes enjoy ultra-processed foods (UPFs) such as frozen waffles, boxed mac ‘n cheese, chips, etc.. The average American consumes about 60% of total calories from UPFs; they are readily available, easy to prepare, have a long shelf-life, and can save time.

• What do runners need to know about UPFs? First, let’s define what they are: UPFs contain substances that are rarely used in home cooking—emulsifiers, thickeners, protein isolates, etc. You’ll find those substances in energy bars, fruit yogurts, commercially baked breads, and many grab-and-go foods that busy athletes commonly consume.

• UPFs also include sport drinks and protein powders. They are not only convenient, but also digest easily. During extended exercise, when runners need quick and easy carbs, consuming a gel, chomp, or sports drink can easily boost energy. While a swig of maple syrup or a banana can be equally energizing, UPFs are generally easier to manage.  

• In the general population, UPFs are linked with obesity. The more UPFs consumed, the greater the risk for weight gain. In a carefully controlled study with menus matched for carbs, protein, fat, fiber, and palatability, the UPF-menu led to weight gain. The UPF-eaters consumed about 500 additional calories a day when compared to when they ate from the whole foods menu—and they gained about two pounds in two weeks. Yikes! Why did that happen? Are UPFs easier to overeat because they require less chewing? Can be eaten quickly? Are super-tasty so you want to keep eating more of them?

The answer is yet to be determined. Until such time, your better bet is to consume homemade foods whenever possible. The less packaging in your grocery cart, the better for your waistline (most likely) and the better for the environment (definitely; less trash in landfills).

That said, balance & moderation pave a prudent path. There’s a time and a place for UPFs. If you have a low protein intake, grabbing a protein bar on the run can help you hit your 20-to-30-gram protein target for the meal. If you consume little red meat, an iron-enriched breakfast cereal like GrapeNuts can help fill that gap. For traveling athletes, carrying bars, gels, and carb-based recovery drinks are “safe” (uncontaminated). Safety matters!


• Muscle is constantly being broken down into amino acids and then rebuilt into new muscle tissue. Resistance exercise, such as weightlifting, stimulates the synthesis of new muscle during the 24-hours post-exercise. Including ~0.15 grams high-quality protein per pound of body weight (0.3 g/kg) per meal maximizes muscle protein synthesis. That comes to about 20 grams protein for a 120-lb (54.5 kg) runner and ~30 grams for a 180-lb (82 kg) runner. You can easily  consume that amount in (chocolate) milk, eggs, or tofu.

• Protein’s food matrix, with all the bioactive compounds that accompany the amino acids in natural foods, has a positive influence on the muscle-building effectiveness of the amino acids. For example, eating a whole egg, not just the egg white, more effectively builds muscle tissue. Hence, your best bet is to choose protein-rich foods in their natural state, such as nuts, yogurt, tuna, beans & rice, etc. Whole foods are preferable to the protein isolates in powders and bars.
• Including protein at each meal and snack also offers benefits. Many runners eat too little protein at breakfast and lunch, then devour 2 to 3 chicken breasts at dinner. They’d be better-off enjoying a serving of protein at each meal and snack.
• Vegan runners can indeed consume adequate protein if they are responsible. A vegan meal with just pasta and greens doesn’t do the job. How much protein from plants is enough? The goal is ~1 gram plant-protein/lb (2.1 g/kg) body weight per day. For a 120-lb (54.5 kg) runner, this comes to about 30 grams per meal plus 10 to 15 grams in each of two snacks.

The information on food labels tells the grams protein/serving, as does a quick google-search (protein in half-cup of hummus). Don’t be among the many athletes who comment “most Americans consume way too much protein” and make little effort to replace chicken with enough beans. A big dallop (1/2 c)  of hummus with 8 grams of protein does not equate to the 35 grams of protein in a small (4-oz) chicken breast. Vegans, educate yourself!


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 and books. For more information visit




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