[heptathorp]

I'm not seeing how this evidence points to overeating --> brain impairment. To me it implies brain impairment --> overeating.

> He did that by studying rats that had very specific types of hippocampal damage and seeing what happened to them.

This researcher started with mice that had damage, and observed they overate. This implies brain impairment --> overeating. The other memory studies in the article with obese or lean subjects cannot infer causality.

> However, even though we are beginning to understand that obesity affects the brain, we don't exactly know how [...]

Perhaps the connection is people with brain impairment (either genetic or damage from the environment) tend to overeat, since the brain plays a role in hunger and satiation. Is there evidence that the article omits that backs up the headline?

[ddlatham]

It doesn't directly imply that brain impairment causes overeating either. Perhaps something else is causing both. Causation is hard.

[leetrout]

That's true- and on that note I wonder if it's the gut in general and it's all related in a cycle. (Given the compounding evidence your gut directly affects your brain.)

From http://www.hopkinsmedicine.org/health/healthy_aging/healthy_...: "For decades, researchers and doctors thought that anxiety and depression contributed to these problems. But our studies and others show that it may also be the other way around," Pasricha says.