As addendum to yesterday's conversation on obesity, one element of the diets-are-bad position that doesn't make empirical sense is the similarly counterintuitive, but well-proven, observation that limited starvation is healthy.
Compared to a control group, people who ate 25 percent fewer calories than the recommended daily allowance (and people who ate 12.5 percent fewer calories than the RDA while getting 12.5 percent more exercise) developed lower body temperatures and significantly lower insulin levels and DNA damage, which correlate with longevity. This follows previous studies in which 1) a very low-calorie diet apparently slowed heart aging in humans and 2) animals on such diets exceeded their species' maximum life spans.
The mechanism appears to be the body's release of reservatol, a DNA repairer. Studies in animals show up to 40 percent increases in longevity during calorie restriction, which is a bit hard to square with Ampersand's data showing increases in early death during diets.
Update: Both Jane Galt and Lindsay have more. Having spent a week with the latter in Amsterdam, I can assure that she will never, ever be overweight. Not because she's a particularly good eater (though she may be), but because she's got so much kinetic energy that I spontaneously entered ketosis whenever she stepped in range. A variety of studies show that the physically neurotic, which is to say the fidgety, burn 10-30 pounds a year through wriggling, squirming, tapping, jaw-grinding, pencil-tapping, and leg-shaking. Something to think about.
