Kenneth Ferraro says it's clear that religious people, on average, are healthier than non-religious people.

"They tend to have healthier lifestyles," said Ferraro, a medical sociologist at Purdue University in Indiana. "They are much less likely to smoke, to use alcohol and chemicals, to be sexually promiscuous."

He theorized that because many religions teach self-discipline, religious people would be less likely to be obese than the non-religious, but he had no evidence to support the idea.

What he learned through extensive research was different. Obesity is much more common among religious people than among the non-religious.

"Many religious people tend to use food in the way the non-religious use alcohol, as a social lubricant," he said. It doesn't make sense that obesity would be common among religious people.

"The popular dictum of `moderation in all things' is consistent with many religious views on diet and body weight," he said. "Gluttony was frequently portrayed in the Bible as a sign of moral weakness or lack of discipline: `Be not among winebibbers or among gluttonous eaters of meat; for the drunkard and the glutton will come to poverty.' "

So he analyzed data on religion, religiosity, mental and physical health, self-esteem and body mass index, the calculation that indicates whether an individual is thin, average or overweight.

His most surprising finding was that the most devout people were heavier than those who were less devout or totally nonaffiliated.

Devoutness was measured by church attendance and participation, reliance on and belief in prayer, and whether the individual read religious books, watched religious programs on TV or listened to them on radio.

Ferraro used two primary sources of data: information compiled by MicroCase Corp. on the prevalence of obesity and its relationship to religion in each state in the United States and the Americans' Changing Lives (ACL) national survey, headed by James House, a University of Michigan sociologist of 3,617 Americans 25 and older.