Georgia State researcher examines how your brain talks to blubber

Biologist Timothy Bartness developed an interest in obesity research after studying how hamsters fattened up to prepare for winter
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More than three decades ago, biologist Timothy Bartness studied how Siberian hamsters fattened up during the summer and early fall to prepare for winter food shortages. Curious about the idea of the brain telling the body to plump up, Bartness developed an interest in obesity research. He now directs Georgia State University’s Center for Obesity Reversal and recently received a $2.5 million award from the National Institute of Diabetes and Digestive and Kidney Diseases to study how the body breaks down fat.

Illustration by Renaud Vigourt
Illustration by Renaud Vigourt

Your research explores how the brain communicates with fat. Can we convince our brains to tell our fat to go away? I think a lot of people would like that. The finding that’s attributed to us is that the brain is connected to white fat—that’s the kind people with obesity have too much of. For the first time, we discovered which areas of the brain were connected to fat via the sympathetic nervous system.

What do nerves in fat cells do? First, they are the trigger for fat breakdown. But the second role of the sensory nerves is that the brain needs to know how the fat’s doing: Is it too much? Is it not enough? What happens, unfortunately, when you try to lose weight—which usually means losing fat—the body engages a host of systems to counteract your effort. Communication comes back to the brain, “Hey, we’re losing a whole lot of fat,” and the brain gets engaged to slow down the metabolism and activation of sympathetic nerves that break down the fat. It’s nature’s dirty trick from our perspective, but for our ancestors and in animals, it’s a way to conserve the saved energy in fat.

Is there a practical application for these findings? It’s always a goal, but it’s not as easy as it sounds. One possibility would be to find something that would cause the sympathetic nervous system to turn on. There are drugs that do that, like amphetamines and cocaine, but they have side effects like addiction and increased heart rate. The ideal would be to find something that would turn on this system and just cause fat to be broken down. Alternatively, maybe you can fool the brain into thinking you’re fat when you’re thin through the sensory nerves that feed back from fat to the brain; then it wouldn’t engage in these other processes, and it would be easier to maintain the lost weight. It’s not impossible, but it is difficult. The chance of having some magic pill that allows you to eat what you want and not gain weight is zero. If people are waiting for that, they’re going to be waiting a long time.

This article originally appeared in our November 2014 issue.

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