Thinness May Be A Simple Matter Of Genetics, Attitude

Don’t hate my friend Diane, but she’s beauty-pageant thin and eats chocolate every day. Whether it’s a cookie, a piece of candy or an ice cream sandwich, it’s sweet, rich and fattening. And there she is, 5-8, 125 pounds and pushing 40.

Everybody knows someone who seems to defy the laws of metabolism. There’s the lanky office-mate who downs two doughnuts each morning, the slim sister who’s addicted to Ben & Jerry’s Double Chocolate Swirl.

We all know that life isn’t fair. But with the diet season well under way, can’t we at least learn something from the calorically advantaged? How can they eat all those sweets and not gain weight? “Skinny people are able to eat desserts because they eat reasonably the rest of the time,” says Marsha Hudnall, director of nutrition at Green Mountain at Fox Run, a weight-control spa in Ludlow, Vt. They’ll eat a candy bar, and that’s it. They don’t get upset about it “and go on a binge for the next two weeks,” Hudnall says.

Naturally thin people have “good internal regulation” of their appetites, says Robyn Flipse, a dietitian in Ocean, N.J. They stop eating when they’re full, and feel comfortable with their food choices, Flipse adds. Unlike those obsessed with their weight, skinny people don’t offer excuses or explanations for eating sweets in public, she says.

In fact, nutritionist Faye Berger Mitchell believes this “whole thin craze” has made people very conscious of what they eat in public, to the point where they are almost “ashamed” to enjoy food in front of others. Thin people who indulge publicly may be better off because “if you tell yourself you shouldn’t eat a candy bar at the office, who knows what you’ll go home and eat?” she says.

Not all thin people eat exemplary diets, however. Far from it, say dietitians.

“One of the misconceptions is that thin is healthy,” says Colleen Pierre, a nutritionist. The reason why you see thin people eating candy bars is because they don’t eat much else, so they don’t take in many calories, Pierre says.

“My experience with counseling (skinny) people is that they go without meals, get very hungry and have a soft drink and a candy bar. They get a quick sugar fix, which satisfies their hunger and stops them from eating other healthy foods,” she says.

Of course, these people may seek Pierre’s guidance because they can’t gain weight. As hard as it may be to believe, “people who are too thin have just as hard a time gaining weight as people who are overweight have trouble losing weight,” says Pierre.

Much of the time it’s due to factors beyond their control. That’s because, like obesity, thinness has genetic components. Some people are just born with small bones and bodies. Some “Slim Jims” have very thin muscle mass, which will never get “huge,” no matter how much weightlifting they do, says Pierre.

Aside from body shape, quick metabolism can also be hereditary, says Mitchell. Some studies have shown that people with rapid metabolism will burn excess food, even if given 500 extra calories a day, Mitchell says.