March 22 was World Water Day. So this is a good time to think about the meaning of water in our lives and the worldwide threats to our supply of clean water. To that end, Alexa Fleckenstein, M.D., this site’s resident “water doctor,” discusses the latest water-related craze: “thermogenesis”, which asks the question: Can drinking cold water help you lose weight? Here are her thoughts:
A new study claims that drinking cold water uses up calories, by thermogenesis —a fancy word for heat production. The study showed that about two thirds of the calories you use up when drinking cold water are expended to warm up the water to body temperature. And one third is used up by increased metabolism, triggered by stress hormones such as adrenaline (the “fight-or-flight” hormone).
Cranking up metabolism to burn up calories may sound like a good idea, but flooding our bodies with stress hormones is not what we need in our stressed-out times. To make matters worse, cold water inside your body clamps down the blood vessels in the stomach, hindering digestion. And since we are already a nation with rather compromised digestive systems, this is a high price to pay for weight loss.
The numbers cited in the study are not impressive: By drinking a pint of cold water, you lose 25 food calories. A similar study done a year ago used even colder water—ice cold—and found that you would have to drink 400 glasses to lose one pound. And this minimal weight loss does not come from losing subcutaneous or abdominal fat (the fat you want to lose).
Talking about losing weight by thermogenesis means not talking about the weighty elephant in the room: The combination of too many calories and not enough exercise. One tablespoon of sugar has exactly those 25 calories that you lose by drinking a pint of cold water. Sounds good? Not if you compare it to a can of soda: up to 150 calories. Or a candy bar: same. Or a portion of ice-cream: about 300. Or a slice of pizza: about 350.
When it comes to weight loss, there is no silver bullet—or silver ice cube—that will magically melt off the pounds. You can, however, crank up your metabolism with a hot bath, and end it with a cold shower to lose a few calories (so few it is only worth mentioning to counter this cold water weight loss craze). You’d be better off following the “freshness pyramid” weight loss program described in my book to fill your body with foods that are bursting with both water and nutrition. But when you drink your water, forget “thermogenesis” and keep it safely at room temperature!