The Olympian Diet: Sports Dietitians Reveal What Fuels Elite Athletes [CNET]

An athlete’s diet can make or break them as they go for the gold. Learn how they fuel for the 2024 Paris Olympics.

The 2024 Paris Olympics have officially kicked off and you can catch all the action from now until Aug. 11. It’s impressive to see these athletes participating in so many different sports after all the hard work they’ve put in during training. These athletes have a whole team on the sidelines making sure they’ve got all the resources they need to make sure they’re set up for success. It’s important to be in good shape if you’re an Olympic athlete, but a lot of it is has to do with being properly fueled, rested and prioritizing recovery.

Read more: How to Watch the Olympics 2024: Schedule, Streaming Tips and More

It makes you wonder what the diet of these professional tennis players, soccer players, track stars, swimmers and others looks like. For example, did you know Olympic swimmer Michael Phelps was known to eat 10,000 calories a day while training for the 2008 Beijing Olympics? While it may seem like a lot of calories for the average person, this may be the norm for an athlete training for hours at a time, day in and day out.

We spoke with a couple of experts, specifically sports dietitians who work with Olympic-level athletes, to get the inside scoop on what the diet of an Olympian looks like. Read on to find out what it takes to keep these elite athletes fueled.

How to fuel up like an Olympic athlete

As you can imagine, the diet of an Olympian is more detailed than that of the average person, but just like anyone seeing a dietitian for guidance, it all starts with a plan. Rikki Keen, senior sports dietitian at the US Olympic and Paralympic Committee (USOPC), says that first and foremost, she looks at the athlete’s preferences. 

“No matter the sport, the first step is to start out with individual preferences, tastes and taking into account if they’re vegan, dairy-free, gluten-free and so forth,” she says. Once that’s discussed, she looks at their sport’s training demands, gender, performance goals and blood work results. “The nutritional needs can change and vary according to the training phase, like if they’re off, in-competition, recovery, double sessions,” she explains. Other considerations she takes into account are their daily schedules, travel (domestic versus international) and food availability.   

Laura Moretti Reece, the lead sports dietitian for the female athlete program at Boston Children’s Hospital, likes to first look at the overall adequacy of the athlete’s diet. “Underfueling has a significant impact on performance as well as health consequences to an athlete,” she warns. She approaches nutrition like a pyramid, starting with a base that focuses on adequate calories to support energy needs. “As we move up the pyramid, we start to break down macronutrients, timing and other more specific variables,” she says. 

Additionally, Reece takes into consideration any underlying risk factors, injuries or special needs the athlete may have. When all of this information is collected, she then looks at the training phase the athlete is in. “This is because the overall needs and balance of the diet shifts and changes based on volume and structure of training,” she explains.

One big no-no that most Olympic athletes know to avoid is drinking alcohol during training season. Keen says, “Alcohol promotes dehydration, delays recovery and it is metabolized above all other nutrients.” Other ways it can hinder an athlete is by slowing muscle protein synthesis (the building and repairing of muscles) and altering sleep stages, which is important for physical and mental recovery. Reece points out that since alcohol is a diuretic, it can cause dehydration in athletes, which has a significant impact on performance. “Alcohol also acts as a vasodilator, which increases blood flow to certain tissues in the body; in the case of an injury, this could lead to increased inflammation and delayed recovery,” she says.

Sleep is a key player in making sure the athlete is performing at their best. Keen vouches that sleep is essential and important for recovery and optimal performance. “I always ask about sleep cycles as they can provide insight into nutrition patterns which can affect sleep,” Keen says. She also points out that anxiety can disrupt sleep, so if an athlete is presenting with sleep issues or anxiety, she recommends they discuss it with their physician and/or mental health professional.

How the athlete’s sport influences diet

As you can see, there’s a lot of thought that goes into creating a fueling plan for an Olympic athlete. Then you have to consider the number of calories they will need to eat based on their sport. Keep in mind, each sport will have different requirements, so that’s why it’s helpful to have a sports dietitian on your team. 

“Beyond the individual metabolic needs that are based on different body compositions, such as lean mass, calorie requirements are determined by the physiological demand of that sport,” says Keen. She explains that athletes in sports that promote a higher heart rate and include longer sessions will need more fuel. For example, if you compare the sport of shooting against swimming. She says, “Calories can differ by 2,000 to 4,000 calories a day — with swimming having higher fuel demands.” 

Reece agrees and says that athletes in sports with higher aerobic demands will require more fuel to help them keep up. “Marathon running often requires a higher percentage of carbohydrate in the diet than strength-based sports, like weightlifting,” she says. Regardless of the sport, she points out that all athletes need carbs, but the percentage shifts based on the energy system the body is utilizing.  

Reece says each sport has its own evidence-based calorie ranges and reaching this number requires using a grams per kilogram of bodyweight approach. This is where additional testing is helpful for a sports dietitian working with an athlete. 

“If an athlete has had metabolic testing done to better understand their resting metabolic rate, or body composition testing, I am able to use other precise evidence-based methods to help meet their energy needs — which are mainly formulas that these values are plugged into,” Reece explains. This also applies if an athlete uses a wearable like a smartwatch or smart ring. She uses this data to better understand the amount of energy they’re expending daily. Lab testing is also useful since these results provide an inside look at how the athlete’s body is functioning internally. “I will often review lab values like iron, thyroid, white blood cells, for example, to ensure an athlete is, in fact, meeting their needs, as sometimes they vary from the calculated ones.” 

Instead of focusing on calories, Keen looks at creating a program for her athletes based on knowing the training demand, goals and meal timing around training sessions. “I calculate the number of grams of carbohydrates and protein needed during training and recovery, as well as fluids and electrolytes,” she says. These factors can vary depending on the prior meal they had before a training session and access to the next meal post-training. Keen points out that in some sports, it can be difficult to eat and drink enough during training, hence why it’s important that the athlete is well-fueled beforehand and the greater focus is on quality nutrition for immediate recovery after their training session. For the sports that do allow fuel breaks and have lower energy demand, she says immediate recovery nutrition is not as necessary since they can typically rely on their next meal in an hour or two post-training. 

Another factor dietitians have to consider is the athlete’s training location. Training in a hot, humid or high-altitude environment can also increase an athlete’s fuel and hydration needs.

The role supplements play in an athlete’s diet

Even with a well-tailored diet, there may be an opportunity for improvement, and that’s where supplements come in. Although Reece and Keen take a food-first approach, they say there are some circumstances where their athletes may require supplements to support their health. Keen says, “Athletes can optimize performance with real food, then as needed use supplements to replete or support the intense level of training and recovery demanded on the body.” This includes using supplements like protein powder or electrolytes, which can be a convenient option for them while traveling. 

Keen prefers to use supplements, mainly to support muscle recovery and training adaptation. These include creatine monohydrate, omega-3s, tart cherry juice and collagen. “We also may recommend supplements based on limited or missing nutrients in the diet, bloodwork results or a high amount of travel,” she explains, adding, “In these cases, it could be probiotics, vitamin D, iron, calcium or a multivitamin.” 

Reece looks at the athlete’s lab values to see if they lack any nutrients and tries to address it both dietarily and supplementally. “Calcium and vitamin D are probably the No. 1 supplements that I recommend to support optimal bone health,” she says. She also recommends an iron supplement since many athletes, particularly menstruating people and endurance athletes, are at a higher risk of iron deficiency. Reece says many of her athletes also take omega-3 supplements for their anti-inflammatory properties. However, she advises using caution when it comes to supplements and consulting with a registered dietitian and/or physician before starting any supplement.

Athletes, in particular, have to be extra careful with supplements because they have to be sure that what they’re taking is free of any banned substances (narcotics, certain stimulants, peptide hormones to name a few) — which can cause them to be stripped of their medals or barred from competition.

The athlete’s diet off-season

An Olympic athlete needs a break, too, after putting in all that work while training and competing. In their case, they have an off-season when they don’t need to train as intensely but instead have to maintain a base level of physical activity. This also influences a shift in their diet since they don’t require as much fuel to keep going. Keen says, “Nutrition during the off-season can differ. However, we still focus on the quality of the food, focusing on color, healthy fats, lean protein, whole grains, as well as monitoring bloodwork for key nutrients.” 

Reece explains that the caloric shift depends mostly on the athlete’s training volume and what activities they’re doing in the off-season to stay fit. “If they are expending less energy through training, their overall caloric requirements will decrease.” However, she warns that it’s important to make sure that the athlete is still meeting their base energy needs to support overall health and avoid falling into a low-energy state, which can ultimately affect their recovery and overall health. To mitigate this, she aims to have her athletes focus on eating more protein during the off-season to help them maintain lean body mass. 

Keen looks at the off-season as an opportunity for some athletes to focus on meeting other goals like leaning up, gaining muscle or even trying a different eating style. “For most athletes, the difference in their diet is in quantity and less structure, allowing for some more flexibility in choices,” she says. She also encourages taking a break from supplements during the off-season if they want, but it’s not necessary. Depending on the athlete’s off-season approach, Keen says the diet may change to meet those goals without affecting training and performance. 

Health tips we can learn from Olympic athletes

Olympic athletes are disciplined, have the best resources at their fingertips and live overall healthy lifestyles. Although the average person may not be training for hours at a time or have access to a coach or dietitian, there are still some good habits Olympians have that we can all follow. Keen suggests that the best way to do this is to plan, prep and keep it simple. “The key is building a routine with meals, timing and being consistent,” she advises. This includes prioritizing batch cooking, meal prep, finding healthy to-go options and adjusting portions to energy demands.  

Reece says if there is one thing the average person can learn from Olympic athletes is that you should be regularly and consistently fueling your body. This means you shouldn’t skip meals and should prioritize protein. “Protein is best absorbed when consumed regularly throughout the day, so eating two meals and expecting to absorb all of your protein needs may be difficult,” she says. Additionally, Reece reminds us that Olympians focus on the consumption of high-quality foods to support their elite level of training. “Eating foods that are nutrient-dense can benefit anyone, and the focus should be on consuming a meal or snack every few hours,” she says. Reece acknowledges that most people may not need the same amount of calories that an athlete training over four hours a day needs, but consistency and not going too long between meals and snacks is important to support a healthy metabolism.

Lastly, your diet doesn’t need to be perfect. Even an Olympian’s diet isn’t strict all the time. 

In Reece and Keen’s experience, Olympians are just like us and enjoy eating treats, and not all of their meals go as planned. Reece says that although Olympians focus on high-quality nutrition, they are also flexible with food. She says, “Eating foods that one enjoys, participating in a birthday celebration or similar occasions are good for the soul and support mental health as well.” Keen agrees and says, “Olympians are just like everyone else when it comes to different tastes and preferences; they have comfort foods, favorite foods and major dislikes, too.”

So keep that in mind next time you order dessert and have a tinge of guilt come over you. If Simone Biles is eating her cake and enjoying it, then you should, too.