The Wonders of Water

How much you really need - and how it can help you lose weight.

By Kathleen Zelman, MPH, RD/LD
WebMD Weight Loss Clinic - Feature

Reviewed By Michael W. Smith, MD

Water is one of the most basic elements of life but figuring out how much we ought to drink hasn't always been so simple.

Most of us grew up thinking we needed to drink eight glasses of water each day, in addition to any other drinks we might choose. But the latest recommendations say that we no longer need to worry about drinking specific amounts of water. Instead, we can simply satisfy our thirst with any beverage.

Of course, water -- clean, refreshing, and calorie-free -- is the ideal beverage of choice. And some folks swear by its weight loss powers, including Mireille Guiliano, author of the best-selling book French Women Don't Get Fat.

To help make the facts about water crystal clear, WebMD asked experts for the skinny on just how much water we need, and whether drinking water can really help keep those extra calories at bay.

The New Fluid Guidelines

A 2002 study published in the American Journal of Physiology questioned the old recommendation of 8 ounces of water, eight times a day. After a thorough review, researcher Heinz Valtin concluded there was inadequate evidence that healthy adults -- living in temperate climates and not engaged in rigorous activities -- need large amounts of water.

For normal, healthy adults, Valtin recommended simply drinking when thirsty. And he reported that even caffeinated drinks can count toward satisfying our fluid requirements.