Appetite and the Brain
I hesitate writing about some of the biology related to eating and weight because I don’t want readers to feel that their biology is fixed and a done deal. There are genetic and metabolic factors which strongly influence appetite and body size, but lifestyle still plays a large role in both. I blog about biology because I want readers to be well informed.
The article “Gut brain link tied to overeating” by Cristy Gelling (Science News, 10/5/13) describes how overeating can be, in part, caused by faulty communication between the gut and brain. Experiments on mice may lead to a strategy of repairing that faulty communication in compulsive eaters. Here’s the gist of the study done with mice based on the supposition that “the more food a person consumes, the less responsive the brain becomes to the pleasure of eating.” In these experiments, it turns out that “by restoring normal communication between the gut and brain, researchers resensitized overfed rodents to the pleasures of both fatty and healthy foods.”
The articles explains that, “In the brain, a chemical called dopamine surges in response to pleasurable experiences like eating, having sex and taking certain drugs. But brain-scanning studies suggest that obese individuals have muted dopamine responses to food. The changes could lead overeaters to seek more and more food to get a pleasurable response.” Researchers suspect that a specific molecule modifies appetite. When given to overfed mice, “the mice had a dopamine surge when fat reached the gut, ate less, and lost weight.” Scientists are thinking that giving overweight humans this molecule might help them eat less and slim down as well.
Of course, researchers don’t know whether approaches which are successful in the lab with rodents are going to work as well or at all with humans. So, where does that leave you? There are several ways you can work this issue. First and foremost is eating mindfully. The slower you eat, the more you’ll enjoy the taste and texture of food. The more you let food sit on your tongue, the more chance taste buds have to sop up flavor. By homing in on taste and satiation, you can then sense that point when your appetite tells you (even subtly) that it’s had enough of a particular food. Second, you can consider that you may be someone who doesn’t easily reach a sense of satisfaction and, therefore, will want to switch your focus to hunger and fullness. Because of your unique biochemistry, you may not recognize satisfaction, but you can tell how your stomach feels and how clothes sit around your tummy whether you have eaten enough. You can also eyeball what seems like enough food for you, eat that amount, and be done.