The categories include nonvegetarians and people considered semi-vegetarians, who eat meat more than once a month but less than once a week.

WSJ: Vegetarians Live Longer Than Meat-Eaters, Study Finds

Once their stomachs are tiny, most patients not only eat far less but also lose the desire to over-eat, possibly because of changes in a hormone called ghrelin that is secreted by the stomach.

ECONOMIST: Obesity: A staple in time... | The