It’s possible that drinking more water will help with weight loss, especially if you replace sweetened high-calorie beverages with plain or carbonated water. That is, of course, as long as you don’t add other high-calorie foods to your diet.
Population studies suggest that people who drink more water tend to consume fewer calories. That doesn’t mean drinking water directly causes you to lose weight, although some experts believe water consumption may affect metabolism. It’s possible that people who drink more water may also be more health-conscious in general, so the water itself could have nothing to do physiologically with the weight loss.
However, drinking water before a meal may help you reduce the volume of food you eat during that meal — at least if you’re middle age or older; studies don’t indicate that young people who drink water before a meal tend to eat less.
There are other non-calorie options other than plain water — you can also drink coffee, tea or herbal tea, but remember that adding milk, cream or sugar will add calories. There are also many diet beverages available that are made with non-nutritive sweeteners.