Eating a healthy diet is a key aspect to losing weight, but many people forget that simply drinking more water is a big step in the right direction.

"Water can decrease your appetite," said Mara Vitolins, a nutritionist at Wake Forest University Baptist Medical Center. "It is hard to distinguish between being thirsty and being hungry, so try drinking water and waiting 20 to 30 minutes to see if you're still hungry."

Vitolins, who also is part of the Center for Research on Human Nutrition and Chronic Disease Prevention, added that drinking water also may help you cut calories.

"Most people drink sodas, coffee, and other such beverages and totally disregard drinking plain water," she said. "Replacing the higher calorie beverages with plain water or flavored water (without added sugar) can significantly reduce calories."

Furthermore, most of these drinks contain caffeine.

"The caffeine acts as a diuretic to set you up for dehydration. By the time you feel thirsty, you already are dehydrated, Vitolins said.

How much water is enough?

Vitolins said one way to calculate how much you need is to take your weight in pounds and divide by two. The result is the number of ounces of water you should drink a day. So a 100-pound woman needs to drink 50 ounces of water each day -- just a little more than four 12-ounce glasses, or three bottles of water (which usually are 500 milliliters or 16.9 ounces.) A 175-pound man would need five bottles of water.

"I think many people would greatly benefit by recording the amount of water they drink in a day," Vitolins said. "Many folks I have asked to do this are surprised at how little they drink."

Drinking plenty of water is as important in the winter as it is during the summer, Vitolins said.

"Most people realize fluid is used to produce sweat, which keeps us cool during exercise and the hot temperatures of summer, but not as many are aware that the body also needs water to stay warm," she said. "The best way to illustrate this is to think of your car. The radiator needs fluid regardless of the weather."

Vitolins said some people need to speak with their physician prior to increasing their water intake, "especially people with kidney problems that require fluid restriction."