Feeling Why am I Hungry After Sex is actually quite common and can be attributed to a few physiological and psychological factors. Sexual activity can be physically demanding, as it involves movement, muscle engagement, and cardiovascular exertion. Just like any other form of exercise, your body burns calories during sex. For some people, the energy expenditure might trigger feelings of hunger afterward, as your body seeks to replenish the calories burned. After sex, the body may start to repair and replenish its energy reserves, including storing fat for future energy needs. This natural process can increase the feeling of hunger as your body seeks to ensure it has enough resources for recovery.