Americans seem to carry bottled water everywhere they go these days. In fact, it has become the second most popular drink (behind soft drinks). But water lovers got a jolt recently when we heard that a new report had found that the benefits of drinking water may have been oversold. Apparently, the old suggestion to drink eight glasses a day was nothing more than a guideline, not based on scientific evidence.

Video Transcript An, R. The Official Journal of the British Dietetic Association, published online Feb. 22, 2016.;News release, University of Illinois at Urbana-Champaign.;CDC: "Finding a Balance." MICHAEL SMITH: It sounds too good to be true. Just drinking more water can help you lose weight. But that's what researchers found. Drinking as little as 1% more water means you'll eat fewer calories. You'll also benefit from a drop in saturated fat, sugar, sodium, and cholesterol. One extra cup of H2O in a day will save you 68 calories. And you don't have to do this every day to get the savings. Drink three extra cups, and you'll cut your calorie intake by 205. To put it in perspective, that's as many calories as you'd burn if you walked two and a half miles. Now, you can't just lie around on the couch all day and chug a gallon of water instead. You still need to keep up those healthy habits. And no word on what happens if you drink more than three cups, except for spending a lot of time in the bathroom. And this doesn't mean you can eat more, just that you're more likely to eat less. But that walk to the water cooler gets you a lot further than you thought. For WebMD, I'm Dr. Michael Smith.

But don't put your water bottle or glass down just yet. While we may not need eight glasses, there are plenty of reasons to drink water. In fact, drinking water (either plain or in the form of other fluids or foods) is essential to your health.

"Think of water as a nutrient your body needs that is present in liquids, plain water, and foods. All of these are essential daily to replace the large amounts of water lost each day," says Joan Koelemay, RD, dietitian for the Beverage Institute, an industry group.

Kaiser Permanente nephrologist Steven Guest, MD, agrees: "Fluid losses occur continuously, from skin evaporation, breathing, urine, and stool, and these losses must be replaced daily for good health," he says.

When your water intake does not equal your output, you can become dehydrated. Fluid losses are accentuated in warmer climates, during strenuous exercise, in high altitudes, and in older adults, whose sense of thirst may not be as sharp.

Here are six reasons to make sure you're drinking enough water or other fluids every day:

1. Drinking Water Helps Maintain the Balance of Body Fluids. Your body is composed of about 60% water. The functions of these bodily fluids include digestion, absorption, circulation, creation of saliva, transportation of nutrients, and maintenance of body temperature.

"Through the posterior pituitary gland, your brain communicates with your kidneys and tells it how much water to excrete as urine or hold onto for reserves," says Guest, who is also an adjunct professor of medicine at Stanford University.

When you're low on fluids, the brain triggers the body's thirst mechanism. And unless you are taking medications that make you thirsty, Guest says, you should listen to those cues and get yourself a drink of water, juice, milk, coffee -- anything but alcohol.