Increased Weight Reduces The Brain's Response To Tasty Food

Increased Weight Reduces The Brain's Response To Tasty Food.
Most common man doubtlessly find drinking a milkshake a pleasurable experience, sometimes extremely so. But apparently that's less apt to be the case among those who are overweight or obese.

Overeating, it seems, dims the neurological answer to the consumption of yummy foods such as milkshakes, a new study suggests. That effect is generated in the caudate nucleus of the brain, a region involved with reward.

Researchers using going magnetic resonance imaging (fMRI) found that that overweight and obese people showed less activity in this brain precinct when drinking a milkshake than did normal-weight people.

"The higher your BMI [body mass index], the moderate your caudate response when you eat a milkshake," said study lead author Dana Small, an ally professor of psychiatry at Yale and an associate fellow at the university's John B. Pierce Laboratory.

The execute was especially strong in adults who had a particular variant of the taqIA A1 gene, which has been linked to a heightened jeopardize of obesity. In them the decreased brain response to the milkshake was very pronounced. About a third of Americans have the variant.

The findings were to have been presented earlier this week at an American College of Neuropsychopharmacology encounter in Miami.

Just what this says about why multitude overeat or why dieters say it's so hard to by highly rewarding foods is not entirely clear. But the researchers have some theories.

When asked how pleasant they found the milkshake, overweight and obese participants in the study responded in ways that did not differ much from those of normal-weight participants, suggesting that the key is not that obese people don't enjoy milkshakes any more or less.

And when they did brain scans in children at gamble for obesity because both parents were obese, the researchers found the opposite of what they found in overweight adults.

Children at jeopardy of obesity actually had an increased caudate response to milkshake consumption, compared with kids not considered at hazard for obesity because they had lean parents.

What that suggests, the researchers said, is that the caudate response decreases as a outcome of overeating through the lifespan.

"The decrease in caudate response doesn't precede weight gain, it follows it. That suggests the decreased caudate reaction is a consequence, rather than a cause, of overeating."

Studies in rats have had comparable results, said Paul Kenny, an associate professor in the behavioral and molecular neuroscience lab at the Scripps Research Institute in Jupiter, Fla.

When rats were given access to extraordinarily palatable, effectively rewarding food for extended periods, they became obese. The fatter they got, the more the comeback in their brain reward centers decreased.

"Over time, the reward systems began to averse down. They were not functioning properly. We think something similar may be going on in humans."

"As you go through your passion and continue to eat these highly palatable foods, you are overstimulating your brain reward center. Over time, the way fights back, and it tones itself down -- which is why the higher the BMI, the less energy you see in the reward area."

Among other things, the brain's caudate nucleus is involved with regulating impulsivity, which is reciprocal to self control, and addictive behaviors.

"The caudate is a region of the brain that receives dopamine. What this mastermind response could mean is that overeating causes adaptations in the dopamine system, which could confer further imperil of overeating."

The question for dieters, then, is whether the caudate response can be restored to normal if they lose weight. The researchers said they didn't certain but planned to test that.

Research in people with other addictions suggests that, over time, there may be some earn to normalcy in the brain's reward processing but perhaps never a rank return to where you started.

A second study to be presented at the meeting found that that the brains of obese people responded differently than the brains of customary weight people to anticipated food or monetary rewards and punishments.

It found that pot-bellied individuals showed greater brain sensitivity to anticipated reward and less sensitivity to anticipated unenthusiastic consequences than normal-weight people. The study was done by researchers at the University of Kansas Medical Center.

Because the findings from both studies were to be presented at a medical meeting, they should be viewed as prelude until they are published in a peer-reviewed journal.

About 30 percent of the U.S. folk is classified as obese, and the medical consequences of that cost more than $100 billion annually, said Dr. Nora Volkow, chief of the U.S. National Institute on Drug Abuse and an scholar on the neurobiology of obesity.

One of the primary culprits behind obesity is the constant availability of "excessively productive food" that, when eaten often, may alter the brain's reward system.

"It's increasingly being recognized that the imagination itself plays a fundamental role in obesity and overeating" saas ko sleeping pills deke.