Science / Medicine : A New Explanation for Fat

New evidence that chubby people have sluggish nervous systems may help explain one of the great injustices of dieting--that some people burn up calories more quickly than others.

The study, published in the New England Journal of Medicine, supports the theory that many fat people get that way because their bodies are extra-fuel efficient.

Earlier research has documented that obese men and women often have lower metabolic rates. Their bodies use up less energy, even when they are doing the same things as ordinary-sized people. So they need less food.

The new study of 56 healthy men, directed by Dr. Hugh R. Peterson of the University of Louisville, may help explain at least part of how this happens. It shows that the fatter people are, the more lethargic their sympathetic nervous system, the internal thermostat that revs up the body in times of danger, stress or exertion.