Sparing of body protein is important for maintenance of lean body mass. Adequate energy and protein intake are vital to prevent catabolism of lean tissue. Dietary carbohydrate is well known for its protein-sparing effects. Sparing protein is of particular importance for an athlete during periods of weight loss, in which maintenance of lean body mass is difficult. When energy intake is restricted, adequate protein intake becomes essential to preserve as much lean tissue as possible. During weight loss, the dietary protein requirement when expressed as a percentage of energy intake climbs as the degree of restriction increases.