October 2021 Issue

Sports Nutrition for Bariatric Athletes
By Carrie Dennett, MPH, RDN
Today’s Dietitian
Vol. 23, No. 8, P. 38

Finding common ground among conflicting nutrition recommendations is key.

Over the course of their career, dietitians may encounter individual clients who have conflicting nutritional needs—but a post–bariatric surgery patient who’s training for a triathlon or marathon can be a particular head-scratcher.

One issue is the knowledge gap. Bariatric patients may not have been active presurgery and therefore may not know how to fuel their bodies for increased activity. Dietitians in bariatric clinics may not have experience with sports nutrition, let alone adapting it for patients with limitations on what, when, and how much they can eat and drink due to their newly altered physiology.

“Their stomach is just so small that it’s easy for them to get dehydrated, and it’s hard for them to eat to fuel themselves easily,” says Nancy Clark, MS, RD, CSSD, a Boston-based sports nutritionist and author of Nancy Clark’s Sports Nutrition Guidebook, which includes a section on bariatric sports nutrition.

“They can do it, but each person is an experiment of one. Each conversation is different.”

Conflicting Nutrition Needs
One of the biggest nutritional conflicts is that bariatric patients are advised to eat protein foods first, only consuming other food groups as pouch space permits. Often, this means getting few carbohydrates, which can become an issue when training for an athletic event—or at least certain events. “When we say athletic performance, what are they doing? If they’re doing power lifting, that’s very different than running a marathon,” says Melissa Majumdar, MS, RDN, CSOWM, LDN, bariatric coordinator at Emory University Hospital Midtown in Atlanta and a spokesperson for the Academy of Nutrition and Dietetics.

While focusing on protein is important to support postsurgical healing, minimize muscle loss that comes with weight loss, and prevent protein deficiency,1 Majumdar says the postsurgery diet isn’t high protein, per se. “In the first six months, people are eating about 500 to 1,000 calories, so intake is pretty low, depending on their pouch size. It’s higher protein in the sense there’s not much coming in overall, so the proportion of protein is higher.”

Compare these restrictions with the dietary needs of a nonbariatric athlete training for a sporting event. Athletes may need 4,000 kcal per day—or more—along with macronutrients adjusted based on the type of sport, the training season, and performance goals, says Laurie Schubert, PhD, RDN, CSSD, LDN, president and founder of Nutrition Heartbeat.

Majumdar says the conflict between nutrition recommendations is less likely to arise during the initial stages after surgery. “At that point, most people aren’t going to be exercising very much; they’re just trying to move more. Our serious exercisers are going to be further out.” She says that about two years post surgery, calorie intake is more like 1,400 to 1,600 kcal per day, making it more feasible for patients to train for a sport and fuel appropriately.

“The closer they are to surgery, the more out of shape they are. As they lose weight, they might walk-jog,” Clark says. “As they lose more weight, they might decide to run. Then they might do a 5K, then think, ‘Oh, maybe I’ll run a 10K, then maybe I’ll do a marathon.’ They also might be feeling their stomach stretch out.”

Schubert agrees that fueling needs are different for someone immediately after surgery. “They’re still adapting to their postsurgery diet and adding in exercise, which they may not have ever really done consistently before. Some people might have dumping after eating carbohydrates or drinking too much fluid,” she says. “I’ve found that with athletes earlier post surgery, it can be easier to add calories during workouts. That way they can keep their small meals, but they also gain more energy during the workouts, so they see more gains and progression in performance.”

Over time—after at least a year and maybe several years—Schubert says bariatric patients can adapt to an athletic eating plan, with plenty of calories, a great amount of hydration, and a wide range of macronutrient distributions depending on their sport and competition level. “This really varies from person to person and with the type of bariatric surgery they had. A Roux-en-Y is more difficult to adapt to, as it’s more invasive and some of the sphincters in the intestines are removed. Sleeve gastrectomies seem to be easier to get past.”

Dumping Syndrome and Hydration
Even when pouch space isn’t an issue, dumping syndrome is. Early dumping syndrome typically occurs 30 to 60 minutes after eating, when bariatric patients consume foods high in refined carbohydrates or fats, which are released rapidly into the small intestine. This can result in symptoms such as abdominal pain, diarrhea, nausea, dizziness, flushing, low blood pressure, and an irregular or fast heartbeat. Late dumping syndrome is related to reactive hypoglycemia (low blood glucose), happening one to three hours after a meal. Symptoms include sweating, tremors, hunger, confusion, and fainting.1,2

Clark says some bariatric athletes can eat almost anything without dumping but can’t tolerate sports drinks, while other athletes safely can include sports drinks or gels. “There’s a lot of nutrition education. Part of that education is that they don’t have to have those goops or sports drinks. I had a client who sucked on jellybeans every 10 minutes. Other people might eat a few raisins. Other people like fruit. There’s nothing magic about those sports products; they’re just convenient. But they are pure sugar and maybe that doesn’t work for them.” Regardless of the ultimate solution, it’s important to find one, she says. “If they get low blood sugar and become dizzy and faint, they can fall.”

Hydration is critical before, during, and after physical activity—especially with higher intensities, durations, and temperatures—yet bariatric patients are advised to avoid fluids for 15 minutes before and 30 minutes after eating to maximize space for food. Staying hydrated means sipping fluids throughout the day because drinking large amounts at once generally isn’t possible, and the inability to consume fluids without restriction can lead to dehydration when the patient is especially active.3 However, Majumdar says that while bariatric dietitians preach to their clients to eat and drink separately, there’s no research showing this is necessary long term. She says it’s important to make recommendations tailored to each client.

Clark says people in larger bodies can sweat a lot, so it’s important for them to know their sweat rate—for example, by weighing themselves before and after one hour of exercising to see how much water weight they lose. “There’s no way they’re able to replace that except over the course of the day,” she says, although eating something salty before exercising can help. Surprisingly, she says worst-case scenarios of dehydration occur less often than one might expect. “Bariatric athletes are so aware of the danger of dehydration that they stay on top of it. They don’t end up in the medical tent because it’s so top of mind. Sometimes being acutely aware of the dangers [results in] better outcomes.”

Schubert once consulted with a woman six months post Roux-en-Y surgery who was training for an Ironman 70.3 (half-Ironman triathlon). “I had to loop her coach in. She couldn’t drink more than a couple of ounces per hour, and she couldn’t take in much in the way of carbs or energy. She lived in Las Vegas, and she wanted to race a summer race in temps above 100°,” she says. “I suggested she wait a year, reconsider her race choice, or risk ending up in the medical tent.” Schubert says that while hydration can be a huge problem shortly after surgery, it’s possible to “train the gut” to absorb more water, carbs, and sodium—for any person, not just bariatric athletes. “This takes time, and it takes attention from athletes so they remember to drink,” she says. “Assuming dumping isn’t an issue, it’s a solvable problem.”

Finding the Right Resources
Unfortunately, many bariatric athletes have trouble finding people who can help them, Clark says. “A lot of them find support groups through their own peers, including through Facebook groups,” she says. “That’s actually where I learned a lot myself. These people are the voice of experience.”

Schubert says bariatric sports nutrition is such a small area of dietetics practice that it’s barely a subspecialty. “I haven’t come across very many sports dietitians who work with this population regularly, and we don’t talk to each other.” She says she’s seen some patients get conflicting information between their bariatric dietitian and herself or other sports dietitians. “I had one woman recently tell me that her bariatric RD panicked when she asked about adding in more carbs with all of her workouts. It was strongly recommended that she not do this so she’d continue her weight loss. This woman is training for an Ironman!”

Majumdar, whose education includes both sports and dietetics, says she’s always felt comfortable with the crossover between bariatric nutrition and sports nutrition. “There are resources, and it’s our responsibility as registered dietitians to find those resources,” she says. For bariatric dietitians who are less comfortable with sports nutrition specifically, she suggests being honest with patients that they aren’t sports dietitians—then meet clients where they’re at, perhaps starting with exploring meal and snack timing. As for sports dietitians who don’t have experience with bariatrics, their bariatric patients may be a valuable resource. “The majority of patients who are seeking sports performance [nutrition counseling] are very comfortable with the [standard] bariatric recommendations,” she says.

According to Schubert, one of the biggest risks of not bridging the gap between bariatric and sports nutrition is relative energy deficiency in sport.4 “This is not taking in enough calories to cover both normal body function and exercise. It’s a more comprehensive version of the female athlete triad, with additions for [gastrointestinal], cardiovascular, hematological, physical performance, and cognitive and psychological deficits,” she says. “I’ve never had a bariatric athlete have these issues, but I figure guarding against them is my job and protects both the athlete and my professional reputation and license.”

What Schubert has seen in bariatric athletes is nutrient deficiencies. “These can be a problem anyway, anemia especially, but athletes sometimes have higher requirements because of their higher caloric needs,” she says. “I’ve seen situations where athletes had to ramp up their supplements beyond the usual postsurgery recommendations.5 Two years ago I had an athlete who was fine but stopped taking his supplements ‘just to see what happened’ when he was ramping up for an Ironman.” She says the experiment didn’t go well, and the client had to go from a double supplement dose for maintenance to a triple dose to get back to normal.

“There needs to be a focus on nutrition quality, and that’s something a bariatric dietitian or a sports dietitian can focus on,” Majumdar says, adding that part of this includes helping patients to be comfortable with what it means to be an athlete. For example, explaining to the patient, “If you’re exercising more, we may need to explore different foods.” She says not getting enough energy is a serious risk that will show itself in muscle wasting, poor performance, or trouble with recovery.

Importance of Education
Clark says the biggest disconnect she sees when working with bariatric athletes is within the person who has been spending his or her life trying not to eat in order to lose weight. “They don’t think they deserve to eat,” she says.

Majumdar agrees: “With our bariatric clients, we’re working to help them reverse a diet mentality while helping them improve nutrition quality,” she says. “That’s where the bariatric dietitian may have a leg up on this population. I think the platform of athletic performance provides the person a really good reason to explore that relationship. ‘If I’m not eating what my body needs, I’ll have this response,’ or ‘My body is telling me I’m bonking,’ or ‘My body is telling me I’m not recovering well.’ That’s something that clients who have been battling weight are not good at. They’re used to relying on the scale.”

Schubert educates her bariatric athletes about current sports nutrition guidelines,
then compares and contrasts them with their bariatric dietitian’s recommendations. “Then I ask the athlete to figure out for themselves where they have problems or deficits and what they might like to try to resolve these issues,” Schubert says, adding that this helps athletes take ownership of their fueling, gives them a chance to experiment without judgment, and it allows her to stay in the loop by asking them about their results. She adds that some people find increasing calories very stressful, so it’s important to address that anxiety and any control issues around food. “The big thing that changes their minds is experiential, when they can complete workouts, feel good while doing those workouts, and be fine to start their next workout. Those positive outcomes really reinforce the importance of fueling correctly for their performance goals.”

Clark agrees that experience is the biggest motivator for helping bariatric athletes understand that they need to eat to fuel their activity. “They have to experiment with eating before they exercise,” Clark says. “Maybe they eat a little watermelon and they realize they feel better and aren’t so tired. As I do with any of my athletes, I say, ‘Try this and see how you feel.’”

Final Thoughts
Research on sports nutrition for bariatric athletes is almost nonexistent, which can create some challenges for dietitians working with bariatric patients. However, Majumdar says dietitians and bariatric athletes can overcome these challenges. “When there’s no research to turn to, it does make me a little nervous,” she says. “But as bariatric dietitians or sports dietitians, we can break it down. We need energy, we need micronutrients and macronutrients, we need to listen to what our body is telling us about how we feel and how our immune system is functioning. Listen to the patient as the source of truth for their body. Either specialty can do this if they’re keeping the patient’s needs and our nutrition science background in mind.”

With no standards, no guidelines, and no best practices, Schubert says it can take much trial and error to synthesize the sports nutrition research with the needs of the athlete. “I use Nancy Clark’s case study on the athlete a lot to tell me what’s working, what’s not, how they’re feeling, how they’re recovering.”6 The case study describes in detail the experience of a marathon runner with gastric bypass, including incidents of hypoglycemia and dehydration, and what she learned about fueling herself effectively. Schubert says she always approaches her athlete clients in a collaborative manner, but that it’s doubly important to do so with bariatric athletes.

“To be a large person in our weight-conscious society is incredibly difficult,” Clark says. “They’ve been on diet after diet after diet, and they feel like failures. When they decide to do a marathon, they’re really committed and they aren’t going to fail. They’re so dedicated and determined and disciplined. They’re a fun group to work with, but they also need knowledge.”

— Carrie Dennett, MPH, RDN, is the nutrition columnist for The Seattle Times, owner of Nutrition by Carrie, and author of Healthy for Your Life: A Holistic Guide to Optimal Wellness.


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2. Quilliot D, Coupaye M, Ciangura C, et al. Recommendations for nutritional care after bariatric surgery: recommendations for best practice and SOFFCO-MM/AFERO/SFNCM/expert consensus. J Visc Surg. 2021;158(1):51-61.

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4. Mountjoy M, Sundgot-Borgen J, Burke L, et al. International Olympic Committee (IOC) consensus statement on relative energy deficiency in sport (RED-S): 2018 update. Int J Sport Nutr Exerc Metab. 2018;28(4):316-331.

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