A free and effective diet trick you can use right now.

One of the most effective ways to lose weight, a new study says, isn’t by taking pills or adopting a fad diet. Instead, it’s by drinking water before meals.

Researchers at Virginia Tech found that subjects who drank 16 ounces of water before each of their three daily meals lost 50% more weight than their control subjects.

Here’s what they did: The researchers divided dieters (who ate no more than 1200-1500 calories per day) into two groups. Half the dieters were told to drink a 16-ounce bottle of water before all three meals. The other half drank water, but were not given any advice about drinking it.

After 12 weeks, both groups lost weight, but the dieters who drank before every meal saw a 44 percent boost in weight loss – about 4.5 pounds greater.

Notably, this technique seems to stick: A year after the study, the water drinkers had continued the regimen on their own and lost additional weight.

So why the difference?

It appears that increased water consumption before a meal reduces feelings of hunger and increases satiety, has no additional calories, and may take the place of other high-calorie drinks that might be consumed. It’s important to note that in this study, the water was consumed before the meal, not simply sipped during the meal. As a result, feeling “full” is much more likely.

Want more evidence? In another study, these same researchers found that adults who drank two cups of water 30 minutes before breakfast ate nearly 75 fewer calories than a group who had not had any water before the meal. So while drinking water is not the cure-all in weight management, staying well-hydrated with water – especially just before meal times – has real benefits.

A general rule of thumb is to divide your weight by two for the number of ounces of water you need each day. Don’t forget to also pay attention to your food portions, eat plenty of fruits and vegetables and strive for a regular level of physical activity.