Eat meals rich in protein, and you won't be as tempted to grab a snack in between.

Researchers from University College London have determined that protein helps us lose weight, not because such foods are more filling, but rather because protein triggers the production of a hormone that stops hunger pangs so we eat less, reports the BBC News.

The best protein to eat? Soy, fish and lean meat.

The hunger-fighting hormone is a peptide called PYY, and researchers have long known that it reduces food consumption by sending signals to the brain that indicate fullness. In this study with mice, the rodents fed a high-protein diet consumed fewer calories and increased their levels of PYY, while mice who were unable to produce PYY ate more and became quite obese.

That's true with people, too. High-protein diets produce the highest PYY levels in the body, which result in the greatest curb in hunger for both normal-weight and obese people. "We have proved that if you do not have PYY, you become obese, and if you give it back, then you lose the weight again," lead researcher Dr. Rachel Batterham told the BBC.

But before you rush out and buy a side of beef, note that dieticians warn that more research is needed before people should make long-term changes to their eating habits. Still, Batterham insists, "It's not a diet that you would go on for a few months. You would go on it for life. We need to check that it would be compatible with lifestyle and look at the safety aspect."

You don't have to eat only protein to benefit. Batterham told the BBC that two less forkfuls of that baked potato and an extra slice of meat will make the difference. That is, make small reductions in how much carbohydrates you consume and increase the amount of protein you eat by just 2 percent to 3 percent.

The study was published in the research journal Cell Metabolism, 2006.

--From the Editors at Netscape