QUESTION: I know you're supposed to drink at least eight glasses of water (or non-caffeinated fluids) a day when you're trying to lose weight, but should they be evenly dispersed throughout the day, or is it OK to drink several glasses at once? I don't really like water, but could probably force myself to drink it a couple times a day.
ANSWER: Nobody has researched this question, says Seattle nutritionist Susan Kleiner, Ph.D., R.D. However, she suspects that drinking throughout the day may be a more effective way to stay well hydrated. "The body likes to stay in balance," Kleiner says. "If you're taking in more fluid than you need at one time, your body gets rid of the excess. Then if you don't drink the rest of the day, you can still get dehydrated." Also, Kleiner says, drinking so much fluid at once may make you feel uncomfortably full. "However, if you want to drink all your water in one or two helpings, that's certainly better than not drinking at all."
Do keep in mind that water isn't the only way to meet your fluid needs. Milk, juice, sports drinks, soups and other noncaffeinated beverages also can help keep you hydrated, although these drinks do have calories. Even caffeinated beverages contribute about half their volume to your daily fluid balance, but go easy on the caffeine for other health reasons.