Results of a study reported in the July issue of the American Dietetic Association Journal showed that drinking water before a meal reduced the energy intake.
 
Participants in the study drank 500mls of water 30 minutes before breakfast (chosen to avoid any effects of food consumed at earlier meals). A buffet-style meal containing typical breakfast foods was offered and participants could choose what they wanted to eat.

The research found that participants consumed significantly less energy (kilojoules) at the test meal after drinking water earlier – 17% less - compared with occasions when water was not drunk beforehand, suggesting that simply drinking a glass of water half an hour before meals may be an effective weight-control strategy and also help increase fluid intake.