Could AC Be Making Us Fatter?

By Stepfanie Romine, for SparkPeople

Air conditioning might be among the modern conveniences taking its toll on our waistlines.

In a study published in the International Journal of Obesity, biostatistician David Allison, Ph.D., and colleagues suggest that America's reliance on AC might be a contributing factor in our obesity crisis.

Allison, a faculty member at the University of Alabama-Birmingham, found a significant "reduction in variability of ambient temperature." The use of AC is now widespread, especially in the South, where obesity rates are highest, and the human body is accustomed to being kept at a fairly steady temperature year-round. Allison and colleagues found that our reliance on central air and heat means we expend less energy, thus burning fewer calories, because we don't have to work as hard to heat up or cool down our bodies.

While climate control is just one of countless contributing factors that have led to the obesity crisis, it is interesting to note that of the 10 states with the lowest obesity rates, all but two (California and Hawaii) are in the northern half of the country, while seven of 10 of the heaviest states are located in the South (Ohio, Indiana, and Delaware are the heaviest states up north).

Another story on the findings points out that Europeans who live in climates similar to the southern states are not as obese--again, while not singling out AC use as a primary cause, it should be noted that southern France and Italy, for example, rely on heavy shutters, thick walls and other old-fashioned forms of climate control than we in the States do.

I've noticed that in both developing and developed countries outside the US, AC use is less prevalent--in Italy, France, Spain, Turkey, Guatemela, and Honduras, I felt much more comfortable on hot days. I love that in other countries, you feel the heat, and a little bit of sweat doesn't gross people out. It's summer, it's hot, we're supposed to sweat!

Just after reading this story about Allison's findings, I happened across a New York Times Opinion section debate on air conditioning: Should Air-Conditioning Go Global, or Be Rationed Away? While I won't dive into the environmental, political, or economic arguments here, I will recommend this take on the subject: Let's Not Let A.C. Turn Us Soft.

Before I started avoiding AC, I was much "softer."

In my youth, I complained relentlessly in summer that the one window unit in our apartment was not adequate. Later, when we moved into a home built in 1912, I didn't understand the work that would have gone into retrofitting such a place with central air. I sweated and I pouted, grateful that I spent summers babysitting for a family with AC. When I moved into my first apartment junior year of college, it had central air, and I was so excited!

But over the years, partly due to my travels and shivering all day long in newspaper offices, I changed my mind about AC.

I gave it up for good last summer. Though there have been some uncomfortable nights--trying to sleep when it's 90 degrees isn't always easy--I feel stronger physically. When I go for runs at night or spend weekend afternoons on the bike path, I don't feel the effects of the heat as I did in years past. I still take the same precautions: sunscreen, hat, layers, plenty of fluids, but spending time outdoors is a treat not a punishment.

A couple of years ago, I confessed that I gain a few pounds every summer. Well, in the summers since I wrote that, I haven't gained weight. I credit that to many things, but partially to being in tune with the climate, which helps me tune in to my hunger. If I had the AC on, I wouldn't mind eating a heavier dinner or turning on the oven. These days, I do everything I can to avoid heating up the kitchen, so I turn to lighter food--lots of salads, chilled bean dishes, and sandwiches. I honestly wait for a cooler night or a weekend morning when I have some extra time, and I cook big batches of basic foods: beans, whole grains, and the like. When I'm hot, my food cravings are different. I don't want heavy foods (though I do still like a really good beer on a hot night); I crave water-rich fruits and veggies.

Here's what else I do to stay cool:

  • Drink water. Lots of it. My rule is that if I'm sweating, I'm sipping. At home, my water bottle is always within reach.

  • Take cold showers. This was a tough one for me, but now I love the refreshing feeling of a cool (lukewarm, really) shower rather than a hot one. Even lowering the temperature 10 degrees can help, and then you don't have to step out into a steamy bathroom. (Bonus: I stop sweating after my summer workouts sooner than when I took hot showers.)

  • Wear fewer clothes. For those of you who live in families or with roommates (or for those who frequently host guests), it might not be as practical, but I live only with my boyfriend. I wear as little as possible that's still decent: a tanktop and running shorts or short, loose sun dresses when I'm at home. He often hangs out in shorts and no shirt.

  • Use fans. I keep an oscillating fan on my desk, we keep ceiling fans running all the time, and use a box fan to create a cross-breeze at night.

  • Keep curtains drawn and blinds closed. My home office is in a corner of the living room that faces south and thus receives quite a bit of light--and heat. To cope with the afternoon sun, I lower the blinds 3/4 of the way and close them.

  • Appreciate the warmth. I relish the warm (warm!) breeze that blows in the window and allows me to smell the trees and flowers outside.


Whether my avoiding AC has any impact on my weight, I don't know for sure. What I do know is that summer's hottest days are easier to deal with now. My seasonal allergies have all but disappeared, too. I appreciate every moment of summer, heat and all.


Related links:

Beat the Heat During Your Summer Workouts

Tips for Staying Cool and Healthy During Extreme Heat

Taking Precautions When Exercising Outdoors


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