June 13, 2006 Your Health
Have you ever wondered why some people can eat whatever they want, and stay thin?
As NBC's Robert Bazell explains, doctors are studying them, to get the skinny, on what makes many of us fat.
When it comes to weight gain, Katie Roberts is one of those people many others envy. "Ok, throw it again." She has stayed thin effortlessly her entire life.
"I have ice cream whenever I want, I have cookies and i don't really think about it."
"Look at the screen and pay attention to the pictures." So what is it about Robert's brain or body that allows that? "What we quickly realized is that some foods have more of an impact on some of us than other foods."
Dr. Dan Bessesen of the University of Colorado Health Sciences Center has grants to study weight gain, but he focuses much of the effort on thin people like Roberts. "
As the environment gets to a point where it's almost normal to gain weight, the unique people become the thin people and they're the people we'd perhaps all want to be like." The researchers are doing extensive metabolic studies of the thin and heavy people, but the major differences so far are in the brain. They scan brain activities as volunteers look at pictures of food and nonfood items Not surprisingly, the brain lights up differently when it sees food and it lights up even more when it sees high calorie food, compared to low calorie items "even if you don't have a weight issue, you look at some of these foods, your brain knows exactly what to do with it." The volunteers are asked to stuff themselves, overeating for three days. Then it's back to the brain scans with food pictures, and now there are big differences. "i think what we're seeing is there are changes in brain regions with overfeeding in thin people." Thin people's brains do not light up when they see food after they are stuffed, but with the heavier people, the brain still has the positive response to food, and the desire to eat, after the person is full." So the proof is in. Thin people are different, and although the difference is in the brain, it is not someone's imagination.Recent reports have shown approximately two-thirds of americans are overweight.