Blah Blah Leptin. Where’s Jen Wade?
I know I’ve heard her talk about “leptin resistance” before, but here is today’s sciencey type news in case you are not friends with La Wade:
“The fullness hormone ‘leptin,’ produced by body fat, normally signals the brain to stop eating. But giving it to obese people doesn’t work — it turned out they do produce plenty of leptin. Now researchers at Oregon Health and Science University say the problem is in the brain…. Cowley’s group studied mice to look for the mechanism behind leptin resistance in the brain. They put groups of mice on either fatty diet or regular chow for 20 weeks — a quarter of the mouse lifespan. Mice that got obese on the fatty diet produced ten times as much leptin as lean mice, but their brains stopped responding to it….Cowley says the finding demonstrates that obesity is a disease, not a character flaw.”
They say the same thing about alcoholism, but do people really believe it? Does it really make a difference?
Posted by mo pie
Filed under: Science
I haven’t read this paper yet, but Michael Cowley is one of the most respected researchers studying the role of the brain in obesity. That being said, the research seems to be presented in a very simplistic way in this article. Certainly, genetics plays a big role in both mice’s and humans’ susceptibility to obesity, and this study underscores that. And alcoholism is a good analogy for it. But clearly, with the rates of obesity rising rapidly over a period of time too short to represent a genetic change in the population, there are clearly other factors involved.
I think leptin resistance is going to be an important thing to understand and could someday be a powerful tool for developing drugs for weight loss in significantly obese people. I wouldn’t say this study is a watershed, but it’s another piece in the puzzle that has been coming together over the last ten years or so.
I doubt leptin resistance is important to weightloss in obese people. True physical hunger has as much to do with that level of obesity as thirst has to do with alcoholism. Both are addictions. Declaring obesity an addiction won’t change the moralistic way non-overweight people look at fat people (guess what? Non-alcoholics also tend to look moralistically at alcoholics). What’s important about seeing obesity as an addiction is that once it’s accepted as such, the ways we treat obesity will become much more effective. Obesity is caused by the brain chemistry that is set in place when food becomes the main (only?) trigger for increased dopamine levels. When eating is the only way you can feel good or even normal, you’ll eat no matter how full you feel.
Leptin controls a lot more than hunger. Its main effects on body weight are actually on metabolic rate and activity level.
And I think in your post, Regina, you are using the term “obesity” interchangeably with binge eating. You’re right that binge eating is very much like an addictive behavior, but not all obese people binge. (You’re also right that binge eating is an understudied and underappreciated aspect of obesity).
I think the main value in understanding leptin resistance is that it will enable us to use leptin as an effective therapeutic tool for the treatment of obesity. And given the potent effects of the leptin system, I’d be shocked if it weren’t useful for people who binge-eat, too.