Scientists Announce Warmer Homes May Lead to More Obesity

Colder weather draws folks into cozy homes, where thermostats may be turned up to ward off the winter chill. However, could toasty indoor temperatures actually contribute to obesity?

Researchers at University College London (UCL) and the Bartlett School of Graduate Studies holler a resounding yes. Publishing in "Obesity Reviews" in January 2011, British epidemiologist Fiona Johnson, M.D., and her team of scientists claim that folks who hover in highly heated homes in winter months are more prone to gaining weight than those who turn their thermostats down even slightly.

The research group studied obesity statistics in the United States, the United Kingdom and elsewhere, comparing winter indoor temperatures in subjects' homes. Apparently, reduced exposure to winter cold can contribute to the human body's ability to maintain a healthy weight in two ways.

Exposure to seasonal cold may help to regulate the human body's natural energy balance.

In recent decades, folks have tended to turn up the heat in their homes during winter months, according to the British study. While higher home temperatures often lead to higher fuel costs, they also seem to discourage dwellers from expending energy of their own. Toasty warm homes may make folks feel more lethargic.

In slightly cooler homes, people may be more likely to move about, thus burning calories and fat. Obviously, shivering burns calories. In fact, the body consumes more energy staying warm, even when temperatures are not cold enough to produce actual shivering or chills.

In addition, people who become acclimated to warmer indoor temperatures may find it more difficult to adjust to the outdoors, even with layers of cozy winter clothing. This phenomenon, tagged as reduced thermogenic capacity, may discourage folks from participating in outdoor athletics or fitness pursuits during winter months.

Increased exposure to warmer indoor temperatures leads to a loss of healthy brown fat.

Brown adipose tissue (fat), as opposed to white fat, actually helps the human body to burn energy. The British scientific team has proposed that folks who remain indoors in hotter homes in wintertime may lose brown fat, preventing their bodies from burning energy appropriately. Conversely, brown fat seems to be motivated to burn energy, in a sense, by cooler temperatures.

Dr. Fiona Johnson, UCL epidemiological team leader, explained this finding:

"Increased time spent indoors, widespread access to central heating and air conditioning, and increased expectations of thermal comfort all contribute to restricting the range of temperatures we experience in daily life and reduce the time our bodies spend under mild thermal stress - meaning we're burning less energy. This could have an impact on energy balance and ultimately have an impact on body weight and obesity."

Turning down the home thermostat may contribute to weight loss.

Could shivering a bit make folks skinnier? The British researchers have suggested that this may be so.

"The findings suggest that lower winter temperatures in buildings might contribute to tackling obesity, as well as reducing carbon emissions," explained Marcella Ucci, a co-author of the UCL study.

Apparently, obesity may be affected by body temperature, hormonal responses to cold and shivering. Even imperceptible shivering may burn calories.

Researchers do not advise tossing winter wear, however.

Although exposure to somewhat cooler indoor temperatures may be linked to healthier weight control in humans, the British researchers are not suggesting extreme cold therapies or carefree romping in winter weather without proper outerwear and protection.

However, their findings do suggest that a slight drop in the home thermostat, as from 70 (F) to the mid-60s (F) might be a healthy step towards better weight management. This might be one factor in a healthy balance, which might just help to tip the scales in folks' favor - if accompanied by a healthy diet and exercise program.