Nature & Environment

Study Ties Obesity to Temperature and Humidity

Benita Matilda
First Posted: Jun 30, 2014 04:58 AM EDT

Researchers say that adults residing in places that have hot summers are more prone to obesity due to lack of physical activity.

Researchers at the University of Texas, Austin, associated obesity to temperature and humidity. They found that adults residing in counties in the U.S. that have terrible summers, especially if they are humid or rainy, are more prone to obesity. The same holds true for hard winters. According to the study, in counties where winters are cold, cloudy and dark, adults are less physically active and more obese.

This new finding helps explain why certain regions of the U.S. have more obesity than others.  The study maps reveal that people in the Southeast counties are least active and also these regions have high rates of obesity. The active counties that see less obese adults are toward the mountain West where summers are cool and dry.

"Living in Texas as I do, the results really resonated for me," said Paul von Hippel, an assistant professor at the LBJ School of Public Affairs, who wrote the study with doctoral student Rebecca Benson.

During June and July the climate gets extremely hot making it almost impossible for people to go for a jog or walk after work, as it is the hottest part of the day. The study authors say that one has to work out a strategy for the day if a person wants to indulge in any kind of activity. Like early morning jogs or swim or some indoor game of basketball or skating.

City planners need to plan out places to allow people to come out in the summers. "Some planners are more thoughtful about that than others," he said. "A great example of thoughtful planning is the hike-and-bike trail along Lady Bird Lake in Austin, Texas. It's shady, it's next to water and it attracts thousands of walkers, runners and bikers on the hottest summer days."

Other factors that influence obesity are demographics, parks, stores and restaurant.  Even after considering all these factors the researchers say that summer heat and rain or humidity have a great effect on obesity levels.

"In a sense, the importance of weather is obvious, but we looked at some other 'obvious' things, and they didn't pan out," von Hippel said. "For example, going in we knew that Coloradans were exceptionally thin and active, so we expected to find that hills and mountains encourage physical activity. But it turns out that terrain matters very little for activity or obesity. In some mountainous areas, like Colorado, people are very active, but in others, such as West Virginia, they aren't."

The finding was documented that in the American Journal of Public Health.

See Now: NASA's Juno Spacecraft's Rendezvous With Jupiter's Mammoth Cyclone

More on SCIENCEwr