Drinking Water Before Meals Promotes Weight Loss?

In a previous post, I cited articles showing that drinking water can boost metabolic rate and that people who reported drinking more than 1 L of water a day in a 12 month weight loss study experienced greater weight and fat loss.

Now, the impact of drinking water immediately prior to a meal in individuals trying to lose weight was examined in a randomised controlled trial. The study, by Elizabeth Dennis and colleagues from Virginia Tech, is published in this month’s issue of Obesity.

Adults (n = 48; 55-75 years, BMI 25-40) were radomised to either a hypocaloric diet + 500 ml water prior to each meal (water group) or hypocaloric diet alone (nonwater group).

During the 12 week intervention period, both groups dropped around 2 BMI points, but the water group lost ~2 kg or 44% more weight than the nonwater group.

Premeal water intake reduced energy intake from an ad libitum meal at base line, but not at 12 weeks.

This randomised controlled trial clearly shows, that in people on a hypocaloric diet, consuming 500 ml water prior to each main meal leads to greater weight loss than a hypocaloric diet alone.

While part of this effect may well be a reduction in meal size following water ingestion other mechanisms are conceivable. Thus, previous studies have suggested that water drinking can increase metabolic rate. Also, people drinking water with their meals may be less likely to drink caloric beverages, thereby further reducing caloric intake.

Whatever the mechanism, regularly drinking 500 ml water prior to every meal may well be an easy and inexpensive way to help manage your weight.