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...

Want the full story?

Subscribe Now


Get TIME the way you want it

  • One Week Digital Pass — $4.99
  • Monthly Pay-As-You-Go DIGITAL ACCESS$2.99
  • One Year ALL ACCESSJust $30!   Best Deal!
    Print Magazine + Digital Edition + Subscriber-only Content on

Learn more about the benefits of being a TIME subscriber

If you are already a subscriber sign up — registration is free!