Health Article

Good, I thought I was just always hungry! A recent study done in collaboration with researchers at Yale University and the University of Texas at Austin found results which reinforce the notion of obesity as similar to drug addiction.

From the Associated Press:

Drink a milkshake and the pleasure center in your brain gets a hit of happy — unless you're overweight. It sounds counterintuitive. But scientists who watched young women savor milkshakes inside a brain scanner concluded that when the brain doesn't sense enough gratification from food, people may overeat to compensate.

A healthy diet and plenty of exercise are the main factors in whether someone is overweight. But scientists have long known that genetics also play a major role in obesity — and one big culprit is thought to be dopamine, the brain chemical that's key to sensing pleasure.

Eating can temporarily boost dopamine levels. Previous brain scans have suggested that the obese have fewer dopamine receptors in their brains than lean people. And a particular gene version, called Taq1A1, is linked to fewer dopamine receptors.

"This paper takes it one step farther," said Dr. Nora Volkow of the National Institutes of Health, a dopamine specialist who has long studied the obesity link. "It takes the gene associated with greater vulnerability for obesity and asks the question why. What is it doing to the way the brain is functioning that would make a person more vulnerable to compulsively eat food and become obese?"

From US News & World Report:

A gene could help prod people to overeat and gain excess weight, new research shows.

The finding probably won't provide a "magic bullet" for weight loss, but it does reinforce the value of good eating habits and exercise, especially for young people, scientists say.

The study, reported in the Oct. 17 issue of Science, is the latest in a series focusing on the brain's response to food using the neurotransmitter dopamine. Cells in the brain's "reward" centers release dopamine when people eat, causing that feeling of pleasure, researchers explain.

Previous studies have shown that some people have fewer brain cell receptors for dopamine, which leads them to eat more to gain the same pleasurable effect. The new study used scans of the brain pleasure centers of a group of women. They revealed a sluggish dopamine response in the brains of some of the women.

"This is the first imaging study which found less activation of dopamine receptors in [some] humans," said study lead author Eric Stice, a scientist at the Oregon Research Institute in Portland.

Women with one form of the D2 dopamine receptor gene had the lowest pleasure response when drinking a milkshake, the scans showed. They had to consume more of the shake to get the same pleasure response. Follow-up study found that these women were also more likely to gain weight over the following year.