Water may contain zero calories, but it’s power extends well beyond simply being a low- (or no-) calorie beverage. Studies show that water can actually help you lose weight. Research shows that drinking just 2 8-ounce glasses of water before meals can help you lose weight, because you eat up to 90 fewer calories. But more than helping you lose weight, drinking water can help you lose belly fat. Why? Dehydration may raise cortisol levels, which inhibits your efforts to lose belly fat. So, stay well hydrated!