Look, there's chef Emeril Lagasse on cable television's Food Network, heaping mounds of butter into the saute pan, melting globs of it in the double boiler, slapping squares of it into the mixing bowl. When he isn't shouting "Bam!" as he spatters food with seasonings, he's declaring, "Pork fat rules!"

Fletcher, a former executive director of the Tufts University Diet and Nutrition Letter, looked at the survival strategies of 208 people who kept off 20 or more pounds for more than 10 years. Their average loss was 64 pounds.

Her subjects all developed their own methods of weight loss and maintenance, dozens of which are described in her books, but Fletcher says their successful campaigns generally began when they realized they wanted to be thin more than they wanted that double-fudge brownie.