Health: The Hormone That Says Stop Eating!

When it was first discovered, scientists dubbed peptide YY3-36 (PYY) the fullness hormone. That's because PYY--a protein produced by the gut--functions as a powerful appetite suppressant, at least in thin people. But would it work for those who need it most, the overweight and obese?

The answer, according to a study in the New England Journal of Medicine, is yes. When 24 volunteers were injected with PYY or a placebo and set loose on a buffet lunch, all the subjects who got PYY--fat and thin--packed away a third fewer calories. The same study revealed that obese people make a third...

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