Alcohol doesn't just lower your healthy-eating resolve, it downright makes you hungrier: According to research published in Alcohol & Alcoholism, just three servings can slash your body's levels of leptin—a hormone designed to squash hunger and keep you feeling full—by 30%. "Alcohol can also deplete your body's carbohydrate stores (called glycogen), causing you to crave carbs in order to replace what was lost," Dr. Decotiis says. And if you find yourself craving salty snacks, dehydration and a loss of electrolytes may be at work.