Watching your waistline? Poor hydration linked to obesity, study finds

Watching your waistline? Pay attention to how thirsty you are, suggests a new study that found a link between poor hydration and obesity.

Using information from a national health and nutrition survey and urine tests to gauge hydration, University of Michigan researchers discovered that those who did not consume enough water were more likely to be obese than hydrated adults.

The thirsty group also had higher Body Mass Index numbers than others.

Drinking water - especially before meals - is a popular technique among those trying to lose weight. But there hasn't been concrete scientific proof of its effectiveness before this study, which expanded the focus to include foods with high water content.

"What we showed is there is a relationship between hydration status and weight status," explained lead author Dr. Tammy Chang.

The study was published in the July/August issue of the journal, the Annals of Family Medicine.

Previous studies on water intake and obesity have produced mixed results. In the Michigan study, the authors reported a "significant association" between inadequate hydration and obesity, adding that the relationship "suggests that water, an essential nutrient, may deserve greater focus in weight management research and clinical strategies."

Those who were well-hydrated likely did not rely solely on water, Chang said. They consumed things like fruits and vegetables, which typically have much more water than processed foods. They're also lower in calories.

How can you tell if you're getting enough water? One of the easiest ways to know is to look at the color of your urine, Chang said. Dark yellow means you are running low on fluids. "If it's more like the color of water, chances are you're pretty well-hydrated," she said.