Alcohol boosts cortisol, a fat-creating hormone and
Drinking heavily or even occasionally increases the body's release of cortisol - the hormone that breaks down muscle and retains fat. This loss of muscle can mean a huge slowdown in one's metabolism, making it easier to gain weight. In addition, alcohol causes a drop in testosterone in men, a hormone which helps burn fat.Alcohol also blocks the body from burning fat.
Because drinking often puts one in a relaxed party mood, it is easier to indulge in snacks, potato chips and other unhealthy party foods -- the more one drinks the less one seems to care.
Simply put, alcohol consumption on a regular basis and weight loss don't mix.