Discovered: The science behind failed weight-loss methods; the truth about multivitamins; old people aren't slow, just careful; the one good thing about ulcers.

• Why it's so hard to keep lost weight off. The Biggest Loser has wowed us all with its transformational powers, turning obese humans into skinny ones. It's inspirational, really. Diet and exercise do work. But have you seen those contestants months after the show's end? They get fat again. Or at least gain some of their weight back. Researchers have now figured out why those who try so hard to lose weight gain it back. "What we see here is a coordinated defense mechanism with multiple components all directed toward making us put on weight," researcher Joseph Proietto told The New York Times. "This, I think, explains the high failure rate in obesity treatment." Translation: Dieting puts ones body in a state, which, post-regimen, triggers a "post-dieting syndrome," making these people hungrier, fixated on food and unable to keep the weight off. It's cruel. And no reward for starving and spinning classes. [The New York Times]

• Old people aren't all that mentally slow. While talking to a grandparent, it might seem like their brains are getting slower as they spew what you consider offensive political beliefs during your weekly phone chats. But research says that's not so. Good news for grandma: "At least in some situations, 70-year-olds may have response times similar to those of 25-year olds," explains Ohio State researcher Roger Ratcliff. When grandpa takes forever to write down a message or type up an email, it's not because they're getting dumb, found the research. It's just that they prefer to do tasks with care. Not like your sloppy careless blogging bull-crap. [Eureka]

Read the full story at The Atlantic Wire.