Why we eat: the science of obesity.

• Author: Mencimer, Stephanie
• Position: Book Review

THE HUNGRY GENE: The Science of Fat and the Future of Thin by Ellen Ruppel Shell Atlantic Monthly Press, $25.00

TWO YEARS AGO, A YOUNG ORGAN transplant doctor told me a harrowing story. Recently he had stood by and watched helplessly as a 15-year-old African-American girl died from an enlarged heart. A transplant might have saved her, but high blood pressure, diabetes, and a body mass of more than 400 pounds made surgery impossible. The memory haunted him as he continued to treat more and more children experiencing the deadly effects of chronic obesity. Mostly poor black kids, they marched through his office suffering from high cholesterol, high blood pressure, enlarged hearts, and adult-onset diabetes that promised to fill their future with kidney failure, amputations, blindness, and early heart attacks and strokes.

Despite the staggering numbers of kids like this who were showing up in District doctors' offices, little was being done about it. The public schools had long since sacrificed physical education to budget cuts; understaffed cafeterias served students Domino's pizza to be washed down with 20ounce bottles of Powerade from school vending machines. The American Diabetes Association, headquartered in nearby Alexandria, Va., did not have a single program in the District for adults, much less children. Even as the casualties mounted, no one was sounding the alarm about all these fat kids. Eventually, though, I discovered that one group of people had taken a keen interest in the local obesity epidemic: drug company researchers. D.C. had so many fat kids, most of whom also had fat parents, that it was a veritable gold mine for gene-hunters looking for new drugs to treat Type 2 diabetes and obesity.

I thought about these kids--and the scientists pursuing them--as I read Ellen Ruppel Shell's new book, The Hungry Gene. As the co-director of the science journalism program at Boston University, Shell's specialty is scientists, and her book is largely a story about them. Her characters run the gamut from geneticists to nutritionists studying indigenous people of Micronesia, where a traditional diet of fish and breadfruit has been replaced by, of all things, Spam. The sum of all their tales isn't particularly heartening for those who may be carrying around a few extra pounds.

As Shell explains, humans are hardwired to get fat. Put us within arm's reach of too much junk food, liberate us from manual labor, and very few will avoid gaining a spare tire. "Obesity represents a triumph of instinct over reason, and as such it embarrasses us," writes Shell. "We prefer to think of ourselves as rational beings, in firm control of our destinies or, at the very least, of our bodies. But the deciphering of the genetic underpinnings to weight regulation has ascertained that it is to some degree...