Amy Stephens
MS, RDN, CSSD, CEDS
Licensed dietitian
specializing in sports nutrition
and eating disorders
7 Nutrition Myths Every Athlete Should Stop Believing
- By Kate Cochran, NYU Cross Country and Track Athlete
- By Amy Stephens, Sports Dietitian
As an athlete, I often come across all kinds of advice—on how to eat, train, and recover—and it can be hard to know what really works. With social media playing such a big role in how we share and learn information, especially from influencers and fitness personalities, it’s easy to get overwhelmed by the sheer amount of content out there. On top of that, there are also long-standing beliefs in the athletic world that have been passed down over time—some of which may not be fully supported by science. While well-intentioned, these ideas don’t always serve athletes in the best way when it comes to health, performance, or recovery.
Myth #1: You need to eat perfectly to perform your best.
I often get comments from friends and family like, “Since you study nutrition and run, you must eat perfectly all the time!” The truth is, I’m far from a “perfect” eater—and I don’t think anyone needs to be. I’m a big believer that honoring your cravings and enjoying a wide variety of foods is actually part of fueling well for performance. When you constantly strive to eat “perfectly,” it can create a rigid mindset around food, which isn’t sustainable or healthy. In fact, research shows that overly restrictive eating can increase the risk of disordered eating behaviors and lead to chronic underfueling—both of which can negatively impact performance, recovery, and long-term health. Food should support your training, yes—but it should also bring joy, satisfaction, and flexibility. It’s meant to nourish your body and your life.
Myth #2: Sugar should be avoided in an athlete’s diet.
I also hear comments all the time like, “You probably never eat dessert since you’re an athlete,” but that couldn’t be further from the truth. I actually have a pretty big sweet tooth and eat dessert almost every night—because I enjoy it, and it makes me happy. The idea that athletes should avoid sugar just doesn’t hold up, especially for endurance athletes. Our bodies rely heavily on carbohydrates—specifically simple sugars—for energy during training and racing. In fact, if we tried to cut out sugar completely, we’d likely feel sluggish, tired, and under-recovered.
Take GU energy gels, for example. They’re made with simple sugars like fructose and maltodextrin, and they’re designed to deliver quick, easily digestible energy. I use them on long runs all the time, and every time I take one, I feel a noticeable second wind. It helps me finish 13- to 14-mile runs feeling strong instead of drained.
Of course, balance still matters. It’s important to get a variety of nutrients throughout the day—carbs, protein, fats, fiber, vitamins, and minerals from whole foods. But enjoying dessert on top of a balanced diet isn’t going to harm your performance. In fact, there’s no research showing that eating sweets will negatively impact athletic outcomes—only evidence supporting the critical role of carbohydrates (aka sugar) in fueling performance, especially in endurance sports.
Myth #3: Athletes should avoid processed foods.
I hear this one a lot and it’s a pretty big misunderstanding. The word “processed” gets a bad rep, but the truth is, almost all food is processed in some way. It’s extremely hard to eat a diet completely free of processed foods. Processed foods offer a convenient option for busy athletes, helping them maintain energy levels throughout the day.
There’s a big difference between minimally processed and ultra-processed foods.
- Minimally processed foods are things like washed spinach, brown rice, yogurt, or canned beans. They’ve been slightly changed but still keep most of their nutrients and are super healthy.
- Ultra-processed foods are things like chips, soda, candy bars, or fast food. These usually have lots of added sugar, salt, and artificial ingredients. Eating too much of these can be bad for your health.
As an athlete, I rely on certain processed options to fuel training and support recovery. After a hard session, I’m not sitting down to prep a kale salad—I’m grabbing something quick like a bagel or chocolate milk to help kickstart the recovery process. During long runs, I rely on sports gels, chews, and drinks—which are technically ultra-processed but essential to avoid bonking.
And from a performance perspective, there’s science to back this up. Processed carbs like white bread, pasta, and sports nutrition products are rapidly absorbed and provide quick energy—crucial for endurance athletes before, during, and after training. Cutting out all processed foods in the name of “clean eating” can actually backfire. It can lead to under-fueling, nutrient gaps, and a stressful, overly rigid mindset around food. In other words: it can do more harm than good.
Myth #4: BMI is a reliable measure of athletic health.
During my four years of collegiate running, I never once knew—or cared—about my BMI. And honestly, even if I did know it, that number wouldn’t make me run faster or feel stronger.
BMI, or Body Mass Index, is basically a quick calculation based on your height and weight that sorts people into categories like underweight, normal, or overweight. While it can be a rough health check for the general population, it doesn’t work well for athletes. That’s because BMI doesn’t tell you what your weight is actually made of—it can’t separate muscle from fat, bone, or water. And since athletes naturally carry more muscle than most people, BMI often gets it wrong. So relying on BMI as a measure of health or fitness can be misleading—and sometimes even harmful. For me, paying attention to how I feel, how I recover, and how I perform has always been way more useful than fixating on a number that doesn’t show the full picture.
Myth #5: Lighter=faster.
This is such a common—and extremely harmful—myth in the running world. The idea that losing weight automatically makes you faster might sound straightforward, but it’s way more complicated than that. In reality, chasing a lower weight often leads to underfueling, which can cause low energy, poor recovery, hormone issues, and a higher risk of injury. When you’re not eating enough, your body doesn’t have the fuel it needs to perform—so you’re more likely to crash mid-run, get injured, or hit a plateau. Speed doesn’t come from shrinking your body; it comes from fueling well, building strength, and training smart. Muscle gives you power and efficiency, which are key in endurance sports. Personally, I’ve felt my strongest and fastest not when I was at my lightest, but when I was eating enough, lifting regularly, and prioritizing recovery. Lighter doesn’t equal faster—stronger does.
Myth #6: Protein over carbs.
There’s a lot of talk about whether carbs or protein should take priority in an athlete’s diet. While protein is important for recovery and muscle repair, endurance athletes rely heavily on carbohydrates as their primary fuel source. Skimping on carbs in favor of high-protein, low-carb diets—like many influencers promote—can actually hurt performance and leave you feeling drained.
While protein is important for muscle repair, carbs are what keep you going during the work. For reference, research recommends that endurance athletes consume roughly 6-12 grams of carbohydrate per kilogram of body weight per day, and roughly 1.2-1.4 grams of protein per kilogram of body weight per day, depending on training load. So no, protein doesn’t need to take over your plate—carbs should be front and center if you want to perform and feel your best.
Myth #7: Supplements are key to peak performance.
There are definitely some supplements that can be helpful—especially if a doctor or dietitian recommends them to correct a deficiency. But there are also a lot of products heavily promoted on social media, especially to athletes, that claim to boost performance but have little research to back them up.
Take BCAAs, for example. I frequently see these powders advertised on my instagram feed with promises of better recovery, less soreness, and improved endurance. But the reality is, if you’re already eating enough total protein from foods like chicken, tofu, or whey, you’re getting plenty of BCAAs—plus all the other essential amino acids. So for most athletes, BCAA powders don’t add anything extra.
That’s the case with a lot of these trendy supplements. Instead of jumping to add new powders and pills, start with the basics: make sure your iron, vitamin D, vitamin B-12, vitamin C, magnesium, and calcium are covered through food first. If a blood test shows you’re low, then it might make sense to supplement.
All of the extra “performance-enhancing” stuff you see online usually offers tiny (if any) benefits—while a balanced, consistent diet will give you the biggest return over time. Because supplements are not regulated, they may contain ingredients that could be harmful to both health and athletic performance.
