Scientists say genes are often the culprit By Sandi Doughton
Seattle Times staff reporter
HARLEY SOLTES / THE SEATTLE TIMES
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Rebecca Hildreth started dieting in the fourth grade. Now 29, the Woodinville woman can't recall a day when she wasn't starving herself — or feeling guilty for eating. She has lost weight at least 20 times, and gained it all back.
"It's just a horrible feeling," said Hildreth, who stands 5-foot-5 and weighs more than 300 pounds. "It's worse than anything else in the world."
Like most overweight people, she blames herself for lacking the willpower to stay slim.
"Isn't that what people think?" she asked. "They view you as lazy and undisciplined."
Scientists in the burgeoning field of obesity research don't see it that way.
There's now irrefutable evidence that body weight is largely a function of genes — as much so as height or a family propensity for breast cancer. Those genes are the blueprint for an intricate web of brain chemicals and hormones that regulate appetite and metabolism. In people prone to obesity, new studies show, the system is geared to pack on pounds with exquisite ease while making it devilishly difficult to shed weight.
The findings help explain why diets almost always fail and why gastric bypass and other stomach-reduction surgeries are currently the only way most seriously obese people can slim down permanently.
Drug companies are scrambling to translate recent discoveries into anti-obesity drugs, and experts predict a new generation of medicines will hit the market in five to 10 years.
In the meantime, researchers say, people struggling with their weight — and society's scorn — should take some comfort from the new understanding of why some people get fat and others stay thin.
"Obesity is not a personal failing," said Jeffrey Friedman, a leading geneticist at Rockefeller University in New York City. "Some people are predisposed to become obese and some are not."
Genes and lifestyle
That doesn't mean people can't change their weight through diet and exercise.
Genetics determines the "body-weight ballpark" each person is born into, said endocrinologist David Cummings of the Veterans Affairs Puget Sound Health Care System.
Heavy parents have heavy children, and not just because of lifestyle. Adopted children have body weights more similar to their biological parents than their adoptive parents, Cummings pointed out. Identical twins raised in different households have nearly identical body weights.
"The evidence is very strong that body weight is mostly genetic, with some environmental contributions," he said.
Online resources
･ Jessica and Leo Loos, who both underwent gastric-bypass surgery recently, are chronicling their experience: www.jeleo.com
･ American Society for Bariatric Surgery: www.asbs.org
