Jan 29, 2015
Running on Empty

A new study has found that only one out of four athletes eat enough calories to fuel their workouts and competitions. Here’s an in-depth look at the problem and possible solutions.

By Dr. Pamela Hinton

Pamela Hinton, PhD, is an Assistant Professor of Dietetics at the University of Missouri. Her previous studies have focused on iron deficiency and the Female Athlete Triad.

Imagine the starting point guard on your men’s basketball team sprinting down the court for a lay-up. Extremely fit, a chiseled physique, and a strong, healthy heart, he looks like the picture of health. How would it change your perception if you knew that he routinely eats fewer calories than he needs, depriving himself of both carbohydrate and protein, and that his daily intake of fat, saturated fat, and cholesterol is off the charts?

Now picture a group of female athletes from your school’s volleyball team in line at the cafeteria. On their trays: a small portion of lean chicken, a giant tossed salad with low-fat dressing, and fruit for dessert. These athletes are as healthy as they look, right? What if you knew that two out of three of them will leave the cafeteria hungry after consciously restricting their food intake because they want to lose weight, that they’ll then go on to push their energy-deprived bodies to the max in practices, workouts, and competitions—and that they do this day after day?

We recently put the eating behaviors of a sample group of NCAA Division I athletes under the microscope, and our study revealed some troubling trends. While the reasons why vary between genders and across sports, we found out that the vast majority of athletes do not eat enough calories to fuel their performance. Only 15 percent of the athletes we studied consumed adequate carbohydrate, and only 26 percent consumed adequate protein. Nearly two-thirds of the female student-athletes reported wanting to lose weight, which is almost always at odds with fueling for athletic performance. Many male athletes, while falling short on overall calories, were consuming more than the recommended amount of fat, saturated fat, and cholesterol.

That’s the bad news. The good news is that by simply by getting athletes to eat commit to adequately fueling their bodies, you could see your teams quickly improve. Imagine how such a simple solution, which our research indicates might benefit as many as three out of four of your athletes, could prevent injuries, improve performance, and enhance wellbeing.

Below, I’ll give a rundown of the results of our study, and follow with some analysis as to why athletes are eating the way they are. I’ll also discuss how athletic trainers and strength coaches can educate athletes, sport coaches, and administrators to help solve the under-eating epidemic.


We collected data on the nutritional intakes and eating habits of 345 male and female student-athletes at a Division I university. Participation was anonymous and voluntary. To determine how the athletes’ daily food intakes stacked up against the recommendations for their gender and activity level, we asked each participant to complete a Food Frequency Questionnaire. Using computer software based on the USDA’s food composition tables, we then determined each athlete’s average daily nutritional intake, and broke this data down by sport and gender.

We also asked participants to complete the Questionnaire for Eating Disorder Diagnosis to assess how disordered eating behaviors affect nutritional intake. This questionnaire addressed issues such as the athlete’s fear of gaining weight and their frequency of binge eating or purging behaviors. Based on their answers, athletes were placed into one of three categories: asymptomatic, restrictive disordered eating, or binge eating.

Athletes also answered a set of additional questions regarding their sociodemographic characteristics and dietary behaviors. In this section, we asked them to report their current weight, their desired weight, and whether they used supplements or restricted their intake of carbohydrate, fat, or fluid to change their weight.

When we analyzed our data, we discovered that a large majority of athletes in our sample were eating fewer calories than they needed to fuel their exercise. Using a formula based on energy intake per kilogram of body weight, we found 70 percent of female athletes were falling short of their energy needs. Male athletes’ energy intake per kilogram of body weight was equally inadequate, with 73 percent consuming too few calories.

In the process of short-changing themselves on calories, both male and female athletes were also falling short on carbohydrate and protein intakes. The recommended intake of carbohydrate for athletes is six to 10 grams per kilogram of body weight. Eighty-one percent of the female athletes and 90 percent of the male athletes in our study failed to meet the recommendations for carbohydrate intake. As for daily protein needs—1.2 to 1.7 grams per kilogram of body weight—only 32 percent of females and 19 percent of males were getting an adequate supply.

For many athletes, the desire to lose weight and/or change their body composition seemed to motivate the under-eating. Sixty-two percent of the female athletes in our study reported wanting to decrease their body weight by at least five pounds. For these athletes, insufficient fueling seems to be a direct result of the desire to be thinner—athletes who wanted to lose weight were more likely to report that they purposely restricted their fat or carbohydrate intake. The desire to lose weight was experienced regardless of which sport they played, and the women in our study reported that society—not peers, coaches, or parents—made them feel overweight.

The desire to change body composition influences many male student-athletes’ eating behaviors as well, but the picture is somewhat more complicated. While 23 percent of male athletes reported wanting to lose five pounds, the majority of football, basketball, and baseball players said they wanted to gain weight. With football players, even though many desired to gain weight, the majority consumed significantly less carbohydrate, protein, and fat than male athletes in other sports when we took into account the football players’ larger body size. Basketball players consumed the lowest amount of all macronutrients per kilogram of body weight. These lower relative intakes were due to the combination of greater body weight and lower absolute energy intake compared to male athletes in most other sports.

While they were under-eating in terms of calories, the diets of many male athletes in our study exceeded the USDA Dietary Guidelines for fat, saturated fat, cholesterol, and sodium. Lack of time to seek out proper nutrition seemed to be driving this trend, as many male athletes reported eating meals and snacks away from home. For these athletes, fat is displacing carbohydrate as an energy source, contributing to their inadequate carbohydrate intake.

Nearly one in four males and one in five females reported some type of subclinical disordered eating pattern. Among males, 7.2 percent reported restrictive eating (frequently dieting or fasting to lose weight), and 16.5 percent said they had episodes of binge eating. Among females, 11.1 percent reported restrictive eating and 7.4 percent reported binge eating.


With three out of four athletes consuming less fuel than they need, what happens to their health and performance? In short, they’re more frequently ill or injured, they can’t train to their potential or recover between workouts, and they feel psychologically run-down or even depressed. And because an under-fed brain has trouble concentrating, academic performance can suffer as well.

Dietary energy fuels the biological processes that allow the body to adapt to the stress of training and to recover between training sessions. Protein synthesis and the production of red blood cells are training adaptations that require energy, and repletion of muscle and liver glycogen also requires energy.

Low carbohydrate intake in particular is known to hurt athletic performance. If glycogen stores are low, the ability to perform high intensity activities over time will be limited. The inability to train at high intensity will severely limit an athlete’s capacity to improve their lactate threshold, speed, and maximal strength. Without adequate carbohydrate, athletes are more susceptible to the immunosuppressive effects of exhaustive exercise and more likely to get sick. And because the brain and central nervous system depend on glucose for energy, low carbohydrate availability can cause decreased mental function and even depression.

When athletes don’t get enough protein, the lack of amino acids limits the synthesis of new protein. Protein synthesis and muscle hypertrophy will be limited if protein intake is low, even if total energy is sufficient.

Also, with chronic low energy intake the hypothalamic-pituitary-thyroid axis is suppressed. The resulting hypothyroidism causes the following physical signs and symptoms: bradychardia, postural hypotension, delayed reflexes, and acrocyanosis. Obsessive thoughts about food are another common result when an athlete is not eating enough, leaving the athlete unable to concentrate on school or sport.


Can our findings be generalized to other populations of college athletes? I believe the answer is yes. I think it’s safe to say that our major findings—that many male and female athletes are under-fueling for their activity levels, that the majority of female student-athletes desire to lose weight, and that many male athletes are over-eating on fat and skimping on carbohydrate and protein—probably apply to athletes on most college campuses.

However, our results suggest that huge improvements can be made to the health and wellbeing of many athletes, and quite possibly to an entire athletic department’s performance, with one simple step. Athletes need to be taught that it’s essential to adequately fuel their bodies.

The first step can be to address under-eating directly with athletes, and preseason meetings are a great time to bring it up. Make sure to focus on the message: “There is one extremely simple step you can take to improve your performance, and that is to make sure you are eating enough.”

Using the analogy of the athlete’s body as a race car and food as fuel is a good place to start. Then follow with a brief education session on the importance of carbohydrate and protein in relation to training and performance. If you can, relate actual cases of one or two athletes whose seasons or careers were negatively impacted by inadequate energy. You want to leave athletes thinking, “I don’t want that to happen to me.”

Working with sport coaches is also extremely important, since they have perhaps the strongest influence on athletes’ attitudes about nutrition. If the coach doesn’t send the message that adequate fuel intake is important, or if he or she pushes a weight loss message, athletes are not likely to listen to anyone else who encourages them to fuel up.

Solving the problem also means educating administrators on how under-fueling could be sabotaging your department’s success. Discuss specific solutions with them, including making a plan to survey athletes to assess whether (and to what extent) the problem exists at your school, and suggest putting money into the budget for a nutritionist to work with athletes.

Some under-eating athletes will likely require individual intervention tailored to treat the cause of the problem. If an athlete is restricting calories because of a strongly held belief that performance will improve if they lose weight, or if they under-eat because they are afraid of gaining weight, it’s important to take a cautious approach. You’ll probably get further by encouraging him or her to view increasing food intake as an experiment, rather than a permanent change. Try telling the athlete, “Let’s increase your energy intake for a couple of weeks and see how your body responds. You might be surprised to find that you don’t gain weight. You might even feel better during practices and see your performance improve.” If the athlete agrees to the experiment, support him or her by monitoring changes in heart rate, blood pressure, reflexes, mood, and energy to provide evidence that the experiment is working.

Athletes who under-eat because they have trouble fitting healthy meals into their schedules need a different approach. These athletes will benefit most from practical suggestions on how they can increase their energy intake in ways that take very little time and effort. For example, packing a peanut butter and jelly sandwich and a piece of fruit to eat between classes takes minimal time and preparation. Other athletes would benefit from education on making healthful selections from fast food menus and vending machines. A sports nutritionist can be a valuable resource for this type of information.


Another risk associated with chronic low energy intake is that it may progress into a clinical eating disorder. Research has shown that individuals who are diagnosed with a clinical eating disorder universally have a history of chronic dieting and food intake restriction.

The progression from dieting to eating disorder is influenced by many factors. For some individuals, the precipitating factor is a negative life event like a death in the family or the termination of a long-term relationship. For others, the triggering event is a negative comment about body weight or shape—often from a well-meaning coach, friend, or parent who suggests that the athlete would be more successful if they lost weight.

It is not always easy to differentiate between an athlete who is a chronic dieter and one who has an eating disorder, as eating-disordered athletes tend to carefully hide their problematic behaviors. The hallmark warning sign is when an athlete is unable to correct their disordered eating behaviors even when they are clearly hindering athletic performance. In other words, when the eating disorder becomes more important than the athlete’s sport, the problem is serious. Other warning signs are isolation from teammates and friends, gastrointestinal complaints, absence from team meals, and frequent trips to the bathroom following meals.

If an athletic trainer or coach suspects an athlete is struggling with an eating disorder, he or she should express concern for the athlete’s current and long-term physical and emotional health. Because athletes may resent feeling they are only valued for their athletic performance, it’s best not to focus only on how their under-eating may compromise performance.

An athlete with an eating disorder needs the evaluation and assistance of a qualified therapist, and the athletic trainer’s efforts should focus on supporting him or her in accessing that help. Reassure the athlete that their problem will be treated confidentially and that they will not lose their athletic scholarship if they ask for help. Provide contact information for those on campus who can assist them.


Athletes are bombarded with nutrition advice from many sources, some sound and some disastrous. Messages about how they should look and how much better they would perform if they changed their bodies are clearly finding them as well.

At a time when so many voices are battling for athletes’ attention, it’s imperative that the sports medicine professionals they encounter provide a simple message: If you want your body to perform well and feel good, treat it right by not holding back the fuel it needs.


One way to get athletes to improve their energy intake is by asking them to study their own behavior. Have athletes select three days—two weekdays and one weekend day—when they will be following their typical diet. Ask them to keep a written food diary for those three days. They should record what they eat, how much they eat, and how the food is prepared. Beverages can significantly affect energy and nutrient intake, so athletes should remember to record what they drink as well. In addition, athletes should log their training and/or competition information—the duration, intensity, and time of day they perform their workouts.

Once the diary is complete, have athletes visit the USDA’s Web site, which is equipped with assessment tools to determine the quantities of calories, carbohydrate, fat, protein, vitamins, and minerals they consumed. Next, have athletes divide their weight in pounds by 2.2 to obtain their weight in kilograms. Finally, have them calculate their specific needs based on body weight according to the following formulas, and compare their actual intake to the results:

  • Carbohydrate: 6-10 g/kg of body weight.
  • Protein: 1.2-1.7 g/kg of body weight, depending on sport.

Another way athletes can start to assess the adequacy of their nutrient intake is simply by paying attention to how they feel physically and psychologically. If an athlete experiences fatigue that doesn’t resolve with rest, can’t finish workouts, or has a drop-off in performance, lack of dietary energy may be to blame. If an athlete is hungry all the time or is obsessing about food, he or she is probably not eating enough. Mood changes such as depression, irritability, anxiety, and marked emotional ups and downs can also signal inadequate food intake. If these symptoms are present, advise the athlete to keep a food diary and conduct the self-assessment outlined above to pinpoint areas where he or she are under-eating.

Web resource: http://mypyramidtracker.gov

Shop see all »

75 Applewood Drive, Suite A
P.O. Box 128
Sparta, MI 49345
website development by deyo designs
Interested in receiving the print or digital edition of Training & Conditioning?

Subscribe Today »

Be sure to check out our sister sites: