Just Do It

Deirdre Barrett

by Monica Weymouth

Wed., Sept. 5, 6 p.m., free, Robin's Bookstore, 108 S. 13th St., 215-735-9600, www.robinsbookstore.com

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Stress, breakups, holidays, cupcakes: We have quite a few excuses for our chubby thighs. Harvard psychologist Deirdre Barrett offers another explanation for failed diets and unused gym memberships in her new book, Waistland: A (R)Evolutionary View of our Weight and Fitness Crisis (W.W. Norton, $24.95). Evolution, she argues, is the real culprit behind increasing obesity rates.

"We were designed for the African savannah," says Barrett. "It's hard for us to be in this setting with all these junk foods available and no intrinsic reason to exercise." When she couldn't find a book to explain this to her frustrated clients — many who were simply told to "listen to their bodies" — she decided to write one herself. Our hunter-gatherer instincts, she says, make us reach for sugary, fatty, high-calorie foods and conserve energy. Although we recognize that our pets and zoo animals need meat, grains and pellets full of nutrients, we consider chips and candy "human food." Similarly, although we make sure that hamsters have exercise wheels and understand that dogs need walks to be happy, most people rarely get on the treadmill themselves.

Fortunately, Waistland doesn't just set us up for certain scientific failure. In order to overcome natural impulses, Barrett suggests psychological interventions such as hypnoticlike imagery to see yourself and food realistically. Cognitive behavioral approaches in which you examine the thoughts and rationalizations behind food choices can also be helpful. "It's still possible to lose weight and be healthy," says Barrett. "But it has to be a radical decision."