The relative importance of fat in the athlete’s diet has been undervalued, with potentially harmful effects on immunity as well as endurance performance, according to New York researchers reviewing the effects of diet on immune function in athletes.
While carbohydrate availability is well recognised for its role in immune competency, the role of lipids (fats) in the immune response to exercise has been under-appreciated. In fact, lipids play a crucial role in building and maintaining the immune system and bolstering it against the stress of exercise.
Some experts have recommended fat intakes as low as 20% of total calories. But the New York researchers believe that endurance athletes could boost their consumption as high as 42% of total intake with beneficial effects on performance and immune function and with no adverse impact on the risk of heart disease.
They point out that fat intake may be particularly important for female athletes, in whom low-calorie, low-fat diets are associated with amenorrhea and diminished performance.
The researchers propose a ‘baseline diet’ consisting of 12% protein, 35% carbohydrate and 35% fat. The remaining 18% of total calories should be distributed between these three macronutrient groups in a ratio determined by the type of sport activity: for example, distance runners may take more fat, high-intensity intermittent athletes more carbs and weightlifters more protein.
Sports Med 2002;32(5):323-37