No, it’s not a gimmick. 14 men and women drank 17 ounces of cold (71 degree F) water after eating. Scientists measured their subjects’ metabolic rate…and it rose 30%, beginning 10 minutes after drinking, and peaking at 40 minutes.

Thanks to one of Los Angeles’ best doctors, Ralph B. Martin, M.D., who informed Dr. La Puma of this study at the American College of Physicians’ Southern California meeting last Spring, where Dr. La Puma spoke on “Nutrition: What Internists Need to Know.” La Puma focused on obesity, high blood pressure, and hyperlipidemia or high cholesterol–treatment guidelines here.

In men, fat mainly fueled the increase in metabolic rate. In women, carbohydrates were mainly used as the energy source.

The researchers calculate that their subjects could burn 400 calories extra, every day, if they drank 2 liters (68 ounces, or just over 2 quarts) of cold water.

Read the full study.

What stays in the stomach longest? Protein—not carbohydrate, not fat, not alcohol(!), but protein. Find some lean protein-full recipes, free, here.