by Barbara Berkeley, MD
During the spring, summer and fall in our Cleveland practice I can generally predict that 80% of the patients we see will be losing weight, while 20% will be struggling.
In January and February, the ratio flips.
I've often wondered why weight loss becomes so difficult as the winter wears on. This is especially true in northern Ohio, where below freezing temperatures and daily snow flurries are compounded by an unending expanse of grey sky.
Over the past year, I have become increasingly interested in studies that suggest that changes in ambient temperature may effect weight loss. Some have postulated that exposure to cold is beneficial by increasing the number of fat cells that are beige or brown---cells which actually burn calories rather than squatting like inert storage tanks.
My own personal experience tells me that trips to warm climates cause weight loss, particularly when diet and exercise are held constant. These two ends of the spectrum led me to speculate that the problem with winter weight stalling might be our indoor temperatures.
In the winter, we feel the cold but are actually not exposed to it as much as we think. We scurry from car to house, office or store and spend the great part of the day in a climate controlled environment that sits at around 70 degrees farenheit. Since a great deal of our daily energy expenditure involves small adjustments which are made by the body in the service of keeping us in homeostatic balance, we may be losing that edge during the winter.
Think of it this way: if you wanted to burn energy in your home, you could do it by either turning on your air conditioner and eating up electricity or firing up your heating system and burning gas. Either way, there is a cost to keeping your house at 70 degrees. During the winter, our constant ambient temperature makes it easy for the body to maintain a comfy 98.6 without doing any of the work or expending any energy. But suppose those little corrections up and down are just what the weight loss doctor ordered?
An article in this month's Obesity looks into this very issue, albeit with a slightly different twist. Studying people who live in higher ambient temperatures suggests that taking folks out of their TNZ (thermo neutral zone) decreases their BMI. So maybe I'm on the right track after all.
If your weight loss is stalled as winter ends, consider trying a cooler home, more time out of doors or raising your temperature through sweat-producing work outs. Let me know what you find out!