Does Air Conditioning Make You Fat?

It takes energy to maintain your body temperature. Can you somehow turn that into weight loss?

Monica Reinagel, MS, LD/N, CNS
3-minute read
Episode #103

My friend Jose recently forwarded me an article suggesting that spending a lot of time in air conditioning could cause you to gain weight because your body won’t have to work as hard to cool you down. Apparently, some researchers found that in the Southern United States—where the summers are very warm—obesity rates have increased as air conditioning has become more widespread.

If that were really true, Jose reasoned, we could lose weight, save money and conserve energy—just by turning off the air conditioner in the summer! Jose is always one to look for the win-win situation.

Of course, there’s always a chance that correlations, such as the one these researchers observed between obesity rates and the number of people with central air conditioning, are just due to coincidence. And I strongly suspect that this is one of those cases.

For one thing, it doesn’t really make sense. One reason we often say “burning calories” is because burning calories creates heat.   Why would your body create heat if it were trying to cool down? 

How Does Your Body Cool Itself?

Inducing severe and potentially life-threatening heat stress doesn’t strike me as a very practical weight loss strategy. 

Actually, there is one time when your body might burn more calories when it is trying to cool down. In extremely hot conditions—dangerously hot conditions—your heart rate will increase and you’ll start panting. That is your body’s frantic attempt to cool you down by circulating blood from its overheated internal organs to the extremities, which (hopefully) are a little cooler, and by increasing evaporation from the membranes in your mouth and lungs. 


About the Author

Monica Reinagel, MS, LD/N, CNS

Monica Reinagel is a board-certified licensed nutritionist, author, and the creator of one of iTunes' most highly ranked health and fitness podcasts. Her advice is regularly featured on the TODAY show, Dr. Oz, NPR, and in the nation's leading newspapers, magazines, and websites. Do you have a nutrition question? Call the Nutrition Diva listener line at 443-961-6206. Your question could be featured on the show.