Just Avoid Dessert and Increase Your Activity Level - That's the Cure for Being Fat...NOT
Posted Jan 11 2010 4:08pm
If you treat yourself to a chocolate chip cookie every day, what does that daily dose of 60 calories mean to your long term weight? You would think, all things being equal, that that calorie load would translate into tens of extra pounds over a lifetime. So, while you were svelte when you were in your twenties, that regular cookie intake makes you fat when you are in your fifties. Policy, therefore, should be directed at all the little stuff, like sweetened beverages, portion sizes and moderation, right? If we all only learned to eat a little bit less, especially as children, we'd all be skinny as adults? Goodbye obesity epidemic?
The Disease Management Care Blog liked this idea because it eats cookies rarely. On the other hand, it knows it remains stubbornly overweight. What gives?
Not so fast, say Martijn Katan and David Ludwig with an explanation in the January 6 issue of JAMA. It turns out that human metabolism is wired to expend greater energy as weight goes up, and to preserve energy as weight declines. Not only do energy requirements change as a function of moving fewer or greater poinds, there are also countervailing changes in hormone levels, nervous system activity and the efficiency of the body's energy conservation.
As a result, they write, 'small changes in lifestyle would have a minor effect on obesity prevention.' This means significant and sustained weight loss fall well outside the ability of most persons who are not actively and agressively dieting on a daily basis and even then, most are destined to gain it all back anyway.
To address the societal imbalance between energy input (food calories) and output (the activities of living, supplemented by exercise), exhortations to avoid that cookie and go for a daily walk are unlikely to make Americans generally skinnier. Instead, we're going to need to reconsider the idea that minor painless adjustments in diet and exercise are the fix for the obesity epidemic. We may need to think about getting real with better attention to calorie content, increasing appropriate government regulation, getting public health involved, reexamining agricultural policy and changing the environment to promote much higher levels of physical activity.