Tuesday, March 2, 2010

NYT: In Obesity Epidemic, What's One Cookie?

Check out this genius post by Tara Parker-Pope of The New York Times' "Well" blog.

One excerpt that I found particularly insightful (the beginning of the post):
The basic formula for gaining and losing weight is well known: a pound of fat equals 3,500 calories.

That simple equation has fueled the widely accepted notion that weight loss does not require daunting lifestyle changes but “small changes that add up,” as the first lady, Michelle Obama, put it last month in announcing a national plan to counter childhood obesity.

In this view, cutting out or burning just 100 extra calories a day — by replacing soda with water, say, or walking to school — can lead to significant weight loss over time: a pound every 35 days, or more than 10 pounds a year.

While it’s certainly a hopeful message, it’s also misleading. Numerous scientific studies show that small caloric changes have almost no long-term effect on weight. When we skip a cookie or exercise a little more, the body’s biological and behavioral adaptations kick in, significantly reducing the caloric benefits of our effort.
And another:
As a recent commentary in The Journal of the American Medical Association noted, the “small changes” theory fails to take the body’s adaptive mechanisms into account. The rise in children’s obesity over the past few decades can’t be explained by an extra 100-calorie soda each day, or fewer physical education classes. Skipping a cookie or walking to school would barely make a dent in a calorie imbalance that goes “far beyond the ability of most individuals to address on a personal level,” the authors wrote — on the order of walking 5 to 10 miles a day for 10 years.

This doesn’t mean small improvements are futile — far from it. But people need to take a realistic view of what they can accomplish.
And another:
A person’s weight remains stable as long as the number of calories consumed doesn’t exceed the amount of calories the body spends, both on exercise and to maintain basic body functions. As the balance between calories going in and calories going out changes, we gain or lose weight.

But bodies don’t gain or lose weight indefinitely. Eventually, a cascade of biological changes kicks in to help the body maintain a new weight. As the JAMA article explains, a person who eats an extra cookie a day will gain some weight, but over time, an increasing proportion of the cookie’s calories also goes to taking care of the extra body weight. Eventually, the body adjusts and stops gaining weight, even if the person continues to eat the cookie.

Similar factors come into play when we skip the extra cookie. We may lose a little weight at first, but soon the body adjusts to the new weight and requires fewer calories.
And one more:
Dr. Ludwig still encourages individuals to make small changes, like watching less television or eating a few extra vegetables, because those shifts can be a prelude to even bigger lifestyle changes that may ultimately lead to weight loss. But he and others say that reversing obesity will require larger shifts — like regulating food advertising to children and eliminating government subsidies that make junk food cheap and profitable.

“We need to know what we’re up against in terms of the basic biological challenges, and then design a campaign that will truly address the problem in its full magnitude,” Dr. Ludwig said. “If we just expect that inner-city child to exercise self-control and walk a little bit more, then I think we’re in for a big disappointment.”
Great stuff. Check out the full post here.

1 comment: