LONDON, U.K. (WPVI) -- When you exercise - and whether you're male or female - may affect your weight loss.
A small experiment in britain showed that men burn more fat if they exercise BEFORE eating, while women burn more AFTER they eat.
It's all because of the way muscles are programmed.
Men who eat first only burn the calories they just ate, not fat.
While women burn the most fat within the first three hours AFTER exercise.
That finding also means women who eat too soon after exercise can defeat the fat burning.