A growing body of evidence, including research presented here Sunday, shows that eating enough fish, chicken, lean meat, low-fat dairy, beans, nuts or other protein-rich foods helps people feel full longer. And scientists are searching for the biological reasons for the increased satiety.

The latest findings might help explain why people report feeling ravenous after eating only a lettuce salad for lunch. It also could offer insight into why some dieters lose weight without getting as hungry on programs that allow ample protein, such as the Zone Diet and the South Beach Diet, and Weight Watchers, in which the typical member selects 20% to 22% of calories from protein. The Atkins diet is often high in both protein and fat.

Read more about study findings showing why Zone diet food makes people feel full for a longer period at http://www.usatoday.com/news/health/2005-10-16-protein-diet-hook_x.htm.