You are what you eat, but with the rise of convenient, scientifically optimized sports nutrition products—can you even pronounce some of the ingredients you’re swallowing every day? Are they really even “good” for you?

Studies are increasingly being carried out to investigate what exactly the long-term effects of manufactured and processed gels, bars, and beverages might be. However, with a buzzy new offering (and a high-budget marketing campaign to go with it) introduced daily, it’s almost impossible for scientific research to keep up with the exploding category; one that’s currently valued at $15.6 billion, according to a Grand View Research market report.

The National Institute of Health reports that up to two-thirds of elite athletes utilize dietary supplements (think: creatine, amino acids, protein, caffeine, etc.). According to the report, this supplemental use increased with age, and was more significant among women than men. Worryingly, recent studies have linked these types of popular fueling options to health concerns including diabetes, low testosterone, gut issues, high blood pressure, and dental problems, just to name a few. 

With so much troubling (and often conflicting) news about the health behind supposedly “healthy” foods, one thing that the performance and nutrition experts we spoke to agreed upon is that there is nothing more valuable to the human body than eating a real food diet. But, as convenience reigns supreme and this unregulated product category shows no sign of slowing down, here’s what to avoid, what to include, and how to counteract potentially harmful effects.  

At the end of the day, how many plastic wrappers are in your trash versus banana peels?

More Can End Up Being Less

For one, Boston-based registered dietitian Nancy Clark (author of Nancy Clark’s Sports Nutrition Guidebook) has no major concerns about incorporating sports nutrition products—within reason.

“The dose is always the poison,” she said. “If someone has a protein bar a day, it’s not the worst. If it’s for three meals a day, you have to question if that’s the wisest choice. You always want to get your nutrients from natural foods. At the end of the day, how many plastic wrappers are in your trash versus banana peels?”

Megan Ostler, R.D. and director of nutrition at the interactive fitness platform iFit, agrees that the major long-term intake issue is not necessarily what products contain; but what they don’t.

“High quality supplements can certainly help to fill the gaps for macronutrients, fiber, vitamins, and minerals, [but] my biggest concern is that overconsumption may displace the nutrients found in whole foods,” she said. “This can give users a false sense of health. Someone may be ‘hitting their macro goals,’ but they are missing out on many important nutrients and interactions from whole food consumption.”

She continued, “This displacement of nutrients also occurs when we hyperfocus on certain nutrients. Many consumers will prioritize protein and up their intake at the expense of other nutrients with vital nutrient packages—like legumes and whole grains. The overconsumption of supplements leads to a lack of nutrient diversity, which impacts our overall nutrition and our gut health.”

Gut Check

Gut issues are possibly the most investigated adverse side effect of sports nutrition products. One potential for danger is the high possible presence of endocrine disruptors in plastic packaging, as these are associated with the increased incidence of metabolic disorders. Alas, gut health—like all health—is individual, and what negatively affects one athlete may not affect another.

“Gut health is incredibly complex,” Ostler agreed. “Studies suggest that the gut microbiome, in particular, benefits from a large variety of whole-based plant foods. Some ingredients to be aware of include: sugar alcohols such as erythritol, maltitol, mannitol, sorbitol, and xylitol, as these can all lead to severe GI distress.”

She continued, “Fiber is another common ingredient in supplements, due to its ability to slow digestion, control appetite, stabilize blood sugar, and help with GI motility. However, certain fiber can cause GI distress for some individuals.” Ostler prefers to use digestion-resistant maltodextrin for fiber in her products, because she finds it more tolerable.

Clark doesn’t believe that gut issues would stem solely from consuming sports nutrition either.

“If you’re having problems with gas and bloat, you want to spend time experimenting and doing an elimination diet to see what’s causing it. Some people have problems with things like gels and they experience GI distress and diarrhea. Others can tolerate them just fine. Every food conversation is an individual conversation, which is why it’s important to meet with a registered dietitian.”

Pave Your Own Whey

Ostler notes that one common thing that can definitely cause GI distress, due to its lactose content, is perennially-popular whey protein concentrate: “For those that can’t tolerate whey concentrate, I recommend whey protein isolate (with little to no lactose) or a plant protein alternative,” she said.

Nate Feliciano, owner and head of training at New York City-based Studio 16 and founder of Treo Nutrition also “stands behind protein powder” like Clark and Ostler, as well as creatine, but he agrees that it’s not a case of one size fits all.

“You always need to be careful with supplements because they are not FDA regulated,” he advised. “What they say on the label is not always what they put in the product, and a lot of companies add other ingredients like flavors, so the best advice I can give is stick with a company that you trust.”

“Look at the sugar and carb content while also looking at the serving size,” he added. “Some companies will show 40 grams of protein per serving, when one serving equals two scoops.”

His other warning is to be wary of sports nutrition that is created solely to taste good, and rather to always “keep your goal in mind” when selecting a product.

Ostler agreed that it’s the lack of regulation that’s a cause for worry: “People may be concerned about artificial ingredients and preservatives, but my biggest concern with supplements is the lack of regulation. Because of this, they may not actually contain what is written on the label.”

She advised, “Check that your supplements are made by an NSF-certified manufacturer and have undergone third-party testing. This process helps to ensure that the product’s claims align with its contents. I also caution clients to beware of ‘miracle’ ingredients with extravagant claims. Often, supplement companies will ‘discover’ a new superfood and make unregulated claims about their abilities. That is always a red flag! Look at labels, see if those ingredients have been recognized as generally safe by the FDA, and read up on actual studies.”

Other categories she’s cautious of are weight-loss pills and muscle-building pills, which contain “dangerous, unapproved, and unregulated herbal ingredients.”

“These pills and herbs can have unexpected interactions and dangerous contents,” Ostler said. “For those looking to build muscle or lose weight, skip the miracle pills or herb and opt for well-researched sports supplements, such as protein powders. There is a large body of research on protein for building muscle and curbing appetite and supplements can give you the boost you are looking for, without the potential harmful side effects.”

Truth Decay

With studies citing that poor oral hygiene is common among athletes, Clark believes that it’s likely down to drinks—as opposed to food—as the whole tooth is bathed in the liquid.

Ostler adds that other “potential culprits” for dental issues include “sugary, high-starch foods like chips and crackers, acidic foods like citrus, carbonated drinks, and alcohol.”

“Avoid snacking or sipping throughout the day,” Ostler recommended. “If you choose to consume them, brush or rinse with water after. Sugar-free options may be better for your teeth, but keep in mind that options like diet soda can still cause problems due to their acidity.”

On the note of sugar, Ostler says that it’s a misconception that sugar is the main cause of diabetes.

“Diabetes is a complex disease,” she said. “Many assume that sugar causes diabetes, but this is not the case. There are different types of diabetes. Type 1 is thought to be caused by genetics and environmental factors, but we aren’t 100% sure what those factors are. Type 2 is also linked to genetics and the environment. Being overweight seems to be strongly associated, but there are plenty of people with type 2 that are not overweight. Other risk factors for type 2 include inactivity, age, high blood pressure, and abnormal cholesterol levels, among others.”

Her conclusion? “No single food will lead to diabetes, but certain eating patterns that cause weight gain may increase your risk. To minimize this risk, exercise regularly, and adopt a healthy diet rich in fruits, vegetables, whole grains, nuts, seeds, legumes, and lean protein sources.”

Stay T-Level Headed

Several studies have also been carried out into the potentially harmful effects of sports nutrition on testosterone levels, but Ostler points out that the research is limited, at best.

“Many believe that soy products can decrease testosterone,” she said. “The research here is mixed and inconclusive, as most studies used animals or small populations. Some research suggests that vegetable oil and alcohol intake may decrease testosterone, but this is far from conclusive as most studies have been small and observational, with many confounding variables.”

“Some studies suggest that trans fat intake may decrease testosterone. While the research is rock solid for this claim, trans fats also have other health consequences (like negatively impacting your cholesterol levels) and should be avoided anyway,” she noted. “The bottom line is, there doesn’t appear to be any single food that largely impacts testosterone levels. General healthy practices—good diet, adequate sleep, stress management—may help. If this is something you are concerned about, talk with your doctor.”

Clark agrees that the one thing that comes to mind as a potential risk to testosterone production is eating inadequate calories. For those concerned, she advises them to get a custom meal plan from a professional to ensure they’re fueling properly.

Indeed, Clark sums it up effectively when she said, “It doesn’t help to look at a food as ‘good’ or ‘bad.’ What you had in a day isn’t going to ruin your diet forever. You have to look at the whole diet—it’s the week, the month, the year. Of course it’s always better to eat real food. Food comes in the matrix, with all sorts of synergistic compounds that make it more effective, so that’s why you always want to get your nutrients from the natural source.”