There is a misconception when it comes to losing and maintaining weight. The saying goes “calories in, calories, out.” I think that is the wrong way to look at it. I think we should look at “energy in, energy out.” Sometimes the body requires certain nutrients at different levels. We can look at the macronutrients for examples.
There are times when the body has a greater need of protein. Strength athletes are one group that require a larger intake of protein. Why does this need exist? A strength athlete is lifting weights that will be heavier than the average person who is just lifting to maintain tone. The average strength athlete should intake 1.4-2.0 grams of protein for every kilogram of body weight. Compare this to the RDA for the general public of 0.8 grams of protein for a kilogram of body weight. The strength athlete will have muscles that are continually being repaired and strengthened so that the muscles can get larger and stronger.
Energy in, energy out is also necessary when we look at someone who has been injured. A burn victim is someone who requires a higher intake of protein. Protein intake depends on what the percentage of the body is burned. A higher percentage of burn requires a larger amount of protein intake that is needed to let the body heal and repair.
When we eat carbohydrates in the correct amounts it can be used in the body as energy. An endurance athlete will require a higher intake of carbohydrates to use as energy compared to the general public. Simple sugars can be used for immediate energy Glucose, fructose, and sucrose (simple sugar) are found in fruit, yogurt, and milk. Complex carbohydrates (starch and fiber) are found in grains and vegetables. The average daily intake of carbohydrates for the general public is 45-65%. This is 3-6 grams per kilogram of body weight of carbohydrates for the general public and 6-10 grams per kilogram of body weight for a competitive athlete. Carbohydrate intake can be even higher for those athletes who are ultra-high competitive. Meb Keflezighi, the 2014 Boston Marathon champion, is one ultra-high competitive athlete that comes to mind..
Fat is the primary energy source when the body is at rest and during light to moderate activity. Beyond moderate activity the body will begin to use carbohydrates for energy. The average daily intake of fat in an athlete’s diet varies by sport. Endurance athletes tend to have a lower intake of fat in their diet than sprinters or strength athletes do. The daily intake of fat for the general public is 20-35 percent of the total calorie intake.
Looking at a 25 year old male who is sedentary, with a height of 70 inches, and a body weight of 170 pounds will need 2313 calories per day for energy to maintain his current body weight. If this 25 year old decided to start becoming active his energy needs would have to be increased to 3084 calories per day. If he was beginning an endurance sport his calorie intake of carbohydrates and protein would need to be increased. He would need a higher level of carbohydrates to increase his energy needs for running at higher intensities. If he was beginning a strength routine his carbohydrate and protein intake would need to increase, but the levels of protein would need to be higher to help with increased muscle mass and strength.
Daily energy needs depend on our daily energy expenditures. Counting calories is not necessary. If the energy we intake is measured in the correct daily amounts we can lose weight, maintain our current weight, or meet the needs for activities we pursue in a daily lives.
Fink, H., & Mikesky, A. (2015). Practical applications in sports nutrition (4th ed.). Burlington, MA: Jones and Bartlett.