Can We Solve Our Obesity Crisis By Transforming Fast Food?
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Any veteran of a high-school reunion has noticed what happens to some of their friends when they hit their 30s. They start to puff out, even while purporting to eat and exercise the same as they always have. Until they figure out that their bodies now require less food, the gain continues. It's possible that an age-related slowdown in metabolism is programmed into our genes, but such a pathway is far from known.
The mouse gene discovery also supports a long speculated relationship between diet, genetics and obesity, called the "thrifty gene" hypothesis. It credits high rates of obesity in certain Native American populations to their genes being "thrifty" with ingested calories, thanks to generations of near-starvation conditions. The Pima tribe of Arizona, for example, has nearly double the obesity rate of Mexico. According to this hypothesis, when carriers of the thrifty gene, or genes, are given the rich food of the modern Western diet, their bodies save every calorie they can, in the form of fat, for a caloric rainy day.
As the evidence mounts for a genetic component of obesity--one that likely interacts with diet--we should be open to the great complexity in which the ultimate causes of obesity are enshrouded. There is also growing evidence that the timing of eating and exercise, with respect to each other, can influence how many calories are burned in a given workout. Exercising during an hours-long fast appears to burn more calories than the same activity in a non-fasted state.
Wherever they lead, the roots of obesity are not as straightforward as Freedman describes. I won't argue that there isn't room for improvement in the quality of fast food. But I can't see how bashing Pollanites, a segment of the population that's noticeably non-obese, will help. And I can't see how the obesity problem is likely to be solved by doubling down on the very system that helped create it.