Most athletes love to win! Many factors impact your ability to perform at your best. Some factors are out of your control, such as heat, humidity, wind, altitude, terrain or playing surface, as well as the time of the event, amount of time between events, and perhaps jet lag. But nutritional factors are in your control, including what, when, and how much you eat. Simply put, to perform at your best, you need to know how to eat well enough to fight fatigue and be strong to the finish.

To address the how to eat to perform at your best issue, I looked to the highly respected sports nutritionist Louise Burke PhD. researcher at Australian Catholic University in Melbourne. Here are some key points from her journal article, Nutritional approaches to counter performance constraints in high-level sports competition. This information might inspire you to consult with a registered dietitian/ board-certified specialist in sports dietetics (RD CSSD) who can help you optimize your sports diet.

Eating

• Carbohydrate is a fundamental source of energy for your muscles. It is stored in your muscles as glycogen. Glycogen depletion (“hitting the wall”) is linked with fatigue.

• Carbohydrate is also a fundamental fuel for your brain. Carbohydrate in the blood, known as blood glucose, fuels the brain so it can focus on—and respond quickly to—the task at hand. To optimize athletic performance, you want to maintain adequate blood glucose levels during exercise, as well as start intense exercise with fully loaded muscle glycogen stores.

• Blood glucose gets supplied from your liver as well as from the banana, toast or other form of sugar or starch (carb) you eat before and/or during exercise. Some athletes avoid pre- and during-exercise carbs, fearing it will create intestinal distress. The better path is to train you gut to tolerate foods and fluids. By experimenting during exercise sessions with a variety of carbs (dried pineapple, granola bar, diluted juice) and/or a variety of flavors and brands of commercial products (sports drinks, gels, chomps, etc.), you can learn which fuels settle best. Choosing a variety of carbohydrates can increase the rate they are absorbed and might reduce the risk of GI distress. Having a well-tested fueling plan is helpful.

• Training enhances your ability to burn fat, and it can be further enhanced by adapting to a keto (high fat, very low carb) diet. Given fat stores are essentially limitless, a keto-adapted endurance athlete (theoretically) should be able to perform very well without having to consume additional carbs during exercise, reducing their risk of intestinal upset from drinking/eating during a race. Sounds good, but this theory doesn’t always work. Research shows that keto-adapted athletes can maintain their performance of moderate intensity exercise but experience a performance decline during real-life high intensity competitive endurance events. That’s in part because burning fat, as compared to burning carb, requires more oxygen and at high intensities, such as a break-away to the finish, oxygen supply to the muscle becomes a limiting factor.

Brain function

• Athletes need a well-fed brain to help them concentrate and make wise decisions. A well-fed brain can also help keep you motivated to exercise at a hard pace. To feed your brain, you want to embark upon exercise being well fed, with blood sugar in a normal range (blood sugar can drop overnight) and not be fasted and running on empty. Eat before you exercise!

• Caffeine is known to reduce the brain’s perception of pain, effort, and fatigue (even in athletes who regularly consume coffee). The recommended dose is 1.5-3 mg per pound of body weight (3-6 mg/kg) but one size does not fit all. Experiment to find the dose that’s best for your body.

• Athletes can consume caffeine via gels, caffeinated energy bars, pre-workout supplements, caffeine pills, and coffee. The problem with coffee is the variability of the caffeine content, which makes it hard to identify a specific dose.

• Some performance enhancers do not need to be absorbed into the body to offer beneficial effects. For example, simply rinsing the mouth with a sugar solution/sports drink (and spitting it out) stimulates reward centers in the brain, allowing you to work harder and enhance your performance.

• Rinsing the mouth every 5 to 10 minutes with a menthol-containing solution creates a perceived cooling effect that can help to increase power or speed during prolonged exercise in the heat. But be careful. If you feel cooler—but actually are not cooler, you might over-extend yourself and end up slowing down prematurely.

• Anti-cramping agents such as pickle juice, capsaicin, or spicy tastes might be helpful for athletes who experience muscle cramps. These pungent tastes are thought to “distract” the nerves involved with the cramping muscle and reduce the severity of the cramp. (More research is needed.)

Fluids

• You want to be sure you are optimally hydrated before you start competing. Your first morning urine should be light-colored, not dark and concentrated.

• Whether programmed drinking (according to a plan) is better than drinking as desired, according to your thirst, depends on your sport. For example, a marathon runner can develop a large mismatch between sweat losses and fluid intake. A 10-K runner is less likely to become severely dehydrated.

• The suggested goal is to lose <2% of your body weight over the course of the event (3 lbs. for a 150-lb. athlete). In lab-based research, a loss of >3% of body weight (4.5 lbs.) is linked to reduced performance. In real life, many athletes’ motivation to win over-rides the negative effects of being under-hydrated. Questions remain unanswered: Could underhydrated athletes have performed better If they were better hydrated? Or does being lighter due to dehydration offer an advantage? Stay tuned. Sports nutrition is an evolving science.

Nancy Clark, MS, RD counsels both casual and competitive athletes in the Boston-area (Newton; 617-795-1875). Her best-selling Sports Nutrition Guidebook is a popular resource, as is her online workshop. Visit NancyClarkRD.com for more info.

Reference: Burke, LM. Nutritional approaches to counter performance constraints in high level sports competition. Experimental Physiology, Nov 2021

As you may recall from nursery songs, Mares eat oats and Does eat oats—and so do many athletes. (FYI, the song is actually Mairzy Doats.) Questions arise about oatmeal:

• Is oatmeal beneficial for athletes? 
• Are steel-cut oats better than quick-cooking oats?
• Does oatmeal really “stick to your ribs”?
• And for some, “Why would any athlete even want to eat oatmeal?? It’s so gluey … yuck! 

Let’s take a look at what you might want to know about this popular sports food.

Oatmeal (aka porridge in parts of the world) refers to de-husked oats (groats) that have been cut into small bits (steel-cut) or steamed (to soften the groats), then flattened with rollers (rolled oats). Regardless of the way the groat is processed, all types of oatmeal are 100% whole grain and offer similar amounts of protein, fiber, vitamins, and minerals. What differs is the cooking time, shape (rolled or steel-cut), texture (chewy or smooth), and whether or not they are all natural or fortified with B-vitamins and iron.

Which type is best? The answer depends on your taste preference and available cooking time.

Steel-cut oats take 20 to 30 minutes to cook. They have a chewier texture than rolled oats. Some athletes use a crockpot to cook them overnight. Despite popular belief, steel-cut oats are nutritionally similar (not superior) to rolled oats.

Old-fashioned oats (rolled oats) cook in 5 to 10 minutes and have a firm texture. They can be eaten uncooked with milk, like any dry cereal, or in the form of muesli or overnight oats.

Quick-cooking oats are ready in a minute on the stovetop. Because they are rolled thinner than old-fashioned oats, they cook quicker and have a smoother texture.

Instant oats cook quickly in the microwave. They are pre-cooked, rolled thin, dried, and then rehydrated to be eaten.  They can be fortified (or not) with B-vitamins & iron. Some flavors are sugar-laden and perhaps best saved for dessert.

Benefits from eating oatmeal

• Oatmeal is one of the most affordable whole grains, perfect for hungry athletes on a budget. At least half your daily grains should be whole grains. Oats for breakfast give you a good start to reaching that whole grain goal for the day.
• Oats are a “safe” choice for a pre-event meal. They are low in certain fibers (referred to as FODMAPS) that send some athletes to the porta-toilets.
• Oats contain a type of soluble fiber (beta-glucan) that makes cooked oats gluey—but can be beneficial for endurance athletes. Beta-glucan slows the absorption of carbs over 2 to 3 hours, helping you feel satiated for a long time. Hence, oatmeal sticks to your ribs; it’s a good pre-exercise choice for sustained energy.
• Beta-glucan helps reduce the risk of heart disease if you eat oats in the context of a heart-healthy diet. To achieve this benefit, the daily target is 1 cup dry rolled oats or ½ cup dry steel-cut oats most days of the week.
• Oats have about 5 grams of protein per ½ cup dry serving. A good protein target for breakfast is at least 20 grams, so cook the oats in 1 cup milk (dairy milk, 8 g protein, or soy milk, 7g protein) and stir in 2 tablespoons of peanut butter or ¼ cup of nuts (8 g pro), and you’ll have a super sports breakfast!
• Fortified oats offer extra iron, a mineral important for athletes who do not eat red meat. A packet of plain Quaker Instant Oatmeal offers 40% of the DV for iron; regular oats offer only 6%. Read the Nutrition Facts label for information on iron in the oats you buy.
• Oats have some fiber, but only about 4 grams per serving (1/2 cup dry rolled oats, 1/4 c dry steel-cut oats). Given the daily fiber target is 25 to 38 grams (achieved by only 10% of women and 3% of men), oats make a small contribution—but more fiber than if you were to have just eggs for breakfast.
• Oats contain an antioxidant called avenanthramide (AVA). AVA can reduce the oxidative stress created by vigorous exercise. New research hints pre-exercise oatmeal might have a protective effect that could potentially reduce inflammation and muscle damage. Stay tuned.
• While naturally gluten-free, oats are often processed in a factory that also processes (gluten-containing) wheat. If you have celiac disease, you want to make sure you buy gluten-free oats (Bob’s Red Mill Oats, Quaker Gluten-Free Oats).

How to boost your oat intake

• Oats are versatile. You can cook them in water —or preferably in milk— to add protein, calcium, and creaminess. The suggested ratio is 1 cup (8 oz) of liquid for each half-cup rolled oats or ¼ cup steel-cut oats.
• For a savory option, cook oats in broth, season with soy sauce, or top with sriracha. Or add some cheese and spinach when cooking, then top the oatmeal with a poached egg.
• As an athlete, you lose sodium in your sweat, so don’t be afraid to make oatmeal tasty by sprinkling on some salt. A quarter teaspoon salt per ½ cup dry oats really helps change the bowl of glue into a yummier breakfast.
• Add sweetener, if desired, to make the oatmeal taste even better—honey, maple syrup, raisins, chopped dates. These extra carbs offer fuel for your muscles. According to the US Dietary Guidelines, 10% of daily calories can come from added sugar. That’s perhaps 200 calories (50 grams) of added sugar for an athlete—guilt‑free!
• Don’t have time to cook oats in the morning? Make overnight oats the night before! There’s no wrong way to make overnight oats. In a 16-ounce glass jar (such as a peanut butter jar), combine ½ cup old-fashioned oats, ½ cup milk, ¼ cup Greek yogurt, fruit-of-your choice (banana, berries), and optional add-ins, such as chia seeds and maple syrup. Refrigerate at least 2 hours for the oats to soften, if not overnight.
• Add rolled oats to a recovery shake or fruit smoothie for a thicker texture, as well as for more carbs to refuel your muscles.
• Bake with oat flour (blenderized oats). The Peanut Butter Chocolate Chip Muffin recipe from my Sports Nutrition Guidebook is a good pre-exercise energy booster and fun way to boost your oat intake. Enjoy!

Sports Nutritionist Nancy Clark, MS, RD counsels both casual and competitive athletes in the Boston-area. Her best selling Sports Nutrition Guidebook can help you eat for health and high energy. For more information about her books and online workshop, visit NancyClarkRD.com.

“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, but it is less-yummy 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 rower 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 that 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?

Sports Nutritionist Nancy Clark, MS, RD counsels both casual and competitive athletes in the Boston-area (Newton; 617-795-1875). Her Sports Nutrition Guidebook can help you eat to win. For more information about her books and online workshop, visit NancyClarkRD.com. 

References

1. 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  https://doi.org/10.1111/obr.13330
2. https://www.utoronto.ca/news/nuts-are-not-linked-weight-gain-u-t-study

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 (www.opss.org) 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 (www.ais.gov.au/nutrition/supplements). 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.

What supplements do “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?

Sports 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 NancyClarkRD.com for more information.

References

1. 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 
2. 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
3. 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
4. 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):305-313

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? 

Should athletes eat them or avoid them?

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 that 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.

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. Visit NancyClarkRD.com.

For more information:

• https://podcasts.apple.com/us/podcast/spot-on/id1448760100
  Joan Salge Blake RD PhD with Hope Warshaw RD, Certified Diabetes Educator
• https://foodinsight.org/gut-check-low-calorie-sweeteners-and-the-gut-microbiome/
  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
• https://www.andeal.org/vault/2440/web/JADA_NNS.pdf
  Position of the Academy of Nutrition and Dietetics: Use of Nutritive and Nonnutritive Sweeteners