The NY Times has a fascinating article about weight-loss research that is sure to surprise a lot of folks and piss off those companies who make money pushing diets and diet foods.
Researcher Dr. Jules Hirsch has devoted his life's work to studying the differences between obese and normal-sized individuals, and what he had discovered is that all of us have a natural normal weight range of about 10-20 pounds. It can be heavy or light, depending on our genetics, but it can't be permanently altered. Which means that the rare obese person who is able to keep the weight off is in a constant state of semi-starvation, a state that takes iron will to maintain.
The researcher came to his conclusions by forcing fat people to diet and normal-sized prisoners to become obese. As soon as his subjects were released from his studies, their body mass reverted to its previous state. He also compared the body mass indexes of adoptees and twins to determine that nature, not nurture is responsible for our size.
My personal experience supports Dr. Hirsch's conclusions. Both of my parents maintained normal weights without much trouble and--pregnancy excepted--I've never strayed far from 134-140 pounds, no matter how much or little I'm exercising.
But we don't get to pick out parents, and some people won't win the genetic lottery. For that reason, Dr. Hirsch suggests that our anti-obesity efforts might best be directed at those whose overweight parents put them at an elevated risk of obesity.
I say bring back recess and daily P.E. and use taxation and incentives to decrease our reliance of cars and encourage walking, biking and mass transit. No matter what our size, we'll be in better health. And so will our planet.