Jan 29, 2015Using Dietary Data
By Jonathan Tanguay
As a collegiate sports dietitian, it is my job to educate athletes on hydration, recovery diets, nutrient timing, good food choices, and safe food preparation. Here at Texas A&M University, we monitor our athletes’ dietary practices by periodically polling them about their food choices. As part of a large study, we recently used 24-hour dietary recall surveys to examine what Aggie football players were consuming at different points during the summer conditioning season. Here’s what we found.
The first 24-hour food log survey was taken on an off-day during the summer conditioning phase of the player’s training schedule. At this time, the athletes are doing an almost daily combination of lifting and running in preparation for the upcoming season. It should be noted that on this day, the athletes were served one prepared meal on campus.
The 59 players that were surveyed consumed an average of over 3,700 kilocalories (kcal) on this particular off-day, averaging only about 3.5 grams of carbohydrate intake per kilogram of body weight. With such a low carbohydrate intake, the players’ percent of calories consumed from fat was 39 percent.
Using the Harris-Benedict Equation to estimate calorie needs, we took the average height, weight, and age of the athletes participating in the survey study, factored in an activity level of 1.375 since it was an off-day, and found that the players’ calorie needs were only 3,200 kcal. Overall, the results were poor because energy intake exceeded energy expenditure, carbohydrate intake was too low, and the percent of energy intake from fat was higher than it should have been.
The second 24-hour food log survey was taken the day before the start of two-a-day practices in August. This was following a discretionary week with no organized team training.
On this day, the athletes surveyed consumed an average of over 3,100 kcal, with 34 percent of the calories coming from fat. Again, the athletes averaged about 3.5 grams of carbohydrate intake per kilogram of body weight. Energy needs were calculated to be about the same as on the first survey day.
Though it’s only a small difference in the two surveys’ numbers, this picture is quite a bit closer to what we would like to see in terms of caloric intake and estimated calorie needs. In this second survey, carbohydrate intake worked out to be about 50 percent of total calorie intake–a great improvement–and protein requirements were met. Only fat intake was just a little higher than the ideal.
Our third dietary survey was taken during the third and final week of two-a-days. At this point in the preseason, adequate energy intake, hydration, and recovery is essential to allow the athletes to maximize their preparation for the upcoming season. Nutrient needs increase as athletes have multiple training sessions on a daily basis for consecutive days. Low energy intake can result in loss of muscle mass, fatigue, and increased chance of injury.
We again used the Harris-Benedict Equation to estimate the athletes’ average basal metabolic rate, but due to the increase in activity when compared to the off-days on which we surveyed previously, we estimated the athletes’ activity level to be 2.3. We figured the average energy expenditure to be 5,307.5 calories for the day, but the athletes averaged out to consuming only 4,470 calories on this day.
Calories consumed from fat dropped to 25 percent and carbohydrate intake increased to about 6.5 grams of carbohydrates per kilogram of body weight. While the athletes were not meeting their energy needs, they had increased their caloric consumption in response to increased energy expenditure.
The three survey days told us a lot. The data supported our theory that during the summer months when collegiate football players are “on their own” without any training table meals, they don’t make the best choices. Unfortunately, at this time, the athletes are also often looking to save time and money on food, which translates to poor nutrition a lot of the time.
Thankfully, during two-a-day training sessions when we can offer training table meals to contend with the high energy expenditures, we saw improvement. In addition to catered meals and delivered snacks at the end of the day, we are also able to provide the players with recovery shakes, energy bars, carbohydrate and electrolyte beverages, fruit, nuts, and bagels throughout practices.
We are currently in the spring portion of the off-season and are using the above survey results to guide the focus of our off-season nutrition program. This means working with the athletes to empower them make better choices when the athletic department cannot provide them with all the food they need.
Jonathan Tanguay, MS, RD, LD, is Assistant Director of Performance Nutrition at Texas A&M University.