Key Protein Shows Promise as Natural Diet Aid

A protein found naturally in the body could bring scientists a step closer to developing a natural and effective diet pill, according to a new British study.

Volunteers injected with the protein PYY two hours before mealtime consumed 30% fewer calories when they sat down to eat, without experiencing any difference in the taste of the food or other apparent side effects.

“PYY appears to be a major factor limiting appetite after meals,” researchers from Hammersmith Hospital in London said in the current issue of the New England Journal of Medicine.

But it could be a while before the latest PYY research benefits overweight consumers. Long-term tests have not been done, and the protein, also known as peptide YY3-36, cannot be taken in pill form because it is quickly broken down by the stomach.

Scientists would have to develop a more resilient form or discover a chemical that mimics PYY, which fools the brain into thinking that the body has been fed.

Two hours after PYY was given intravenously, 12 obese patients ate 30% fewer calories from an all-you-can-eat buffet than they did after a saltwater injection. Twelve lean volunteers ate 31% fewer calories. The effect persisted for at least another 10 hours, and even after 24 hours, people in the obese group had eaten 17% fewer calories.