Maureen Michael likes food. Most days, she has three or four meals, and on occasion she eats yet another in the middle of the night. But she rarely worries about her weight, and at 5-foot-8 and 155 pounds, she looks quite trim.
"I eat anything, and I eat a lot," the 51-year-old District of Columbia resident said. "I like large portions. I have one of those metabolisms, I guess."
Just the other day, Michael ate a salad and two large helpings of spaghetti and meatballs for dinner — after having a hearty bowl of ice cream. For breakfast the next morning, she ate two scrambled eggs, half a package of Polish sausage, English muffins and orange juice. For lunch, she consumed a 12-inch seafood sub and some Doritos, and that night's dinner featured two pork chops, potatoes and broccoli.
That Michael's weight remains steady even though she eats whatever she wants and does not exercise interests scientists studying the nation's obesity epidemic. By looking at people who are near their ideal body weight, these reseachers at the National Institutes of Health's Metabolic Clinical Research Unit in Bethesda, Md., hope to figure out what causes so many others to be overweight or uncontrollably fat.
Michael is among the one-third of American adults who are at a good weight relative to their height and build. Another third are overweight, and the rest are obese. Unlike Michael, very few people keep their weight in check without paying attention to what they eat and being conscientious about physical activity.
For years, people have been told to diet, control their appetites, use a little willpower. But more and more scientists believe the obesity epidemic has been triggered by a combination beyond an individual's control: genes, and how they interact with an environment of abundant, tasty, inexpensive and hard-to-resist food.