Research links obesity in the U.S. and U.K. to warmer indoor temperatures
January 31, 2011
A number of factors have been cited for the epidemic of obesity in America and Great Britain: genetics, food consumption and lack of exercise are all familiar culprits. But British researchers believe they may have found another cause—warm houses and workplaces.
In their review, the researchers noted that average indoor temperatures during the winter months have increased since the 1970s in both the U.S. and the U.K.; in the U.S., temperatures have stayed consistently high in the average living room, and nearly 2 degrees F warmer in bedrooms at night, which is significant.
There are also fewer cold pockets in homes, such as in hallways, leading to less exposure to variable temperatures. At the same time, workplace temperatures are believed to be increasing.
The researchers blame all of this on a culture of "thermal monotony" brought about by the widespread use of central air conditioning and heating.
Cooler Temperatures May Burn Fat
Spending most of the day in warmer room temperatures and little time in mild, seasonal cold affects the way the body burns fat; in warmer temperatures, the metabolic rate is lower than at cooler temperatures.
Brown adipose tissue, sometimes called "brown fat," also plays a role by burning more energy in the form of heat in cooler temperatures. But people living and working in consistently warmer indoor temperatures, the researchers argue, have less brown fat and therefore burn less energy.
More research is needed before anyone can prove that warmer room temperatures are a direct cause of obesity, but people want to lose weight might find the prospect of a trimmer waistline from lowering the thermostat back to cooler temperatures worth the gamble.
Johnson F, et al. "Could increased time spent in a thermal comfort zone contribute to population increases in obesity?" Obesity Reviews 2011; DOI: 10.1111/j.1467-789X.2010.00851.x.