WEDNESDAY, March 23 (HealthDay News) -- New research finds that people who frequently attend religious services are significantly more likely to become obese by the time they reach middle age.

The study doesn't prove that attending services is fattening, nor does it explain why weight might be related to faith. Even so, the finding is surprising, especially considering that religious people tend to be in better health than others, said study author Matthew J. Feinstein, a medical student at Northwestern University in Chicago.

"It highlights a particular group that appears to be at a greater risk of becoming obese and remaining obese," he said. "It's a group that may benefit from targeted anti-obesity interventions and from obesity prevention programs."

Scientists have been studying links between religious behavior and health for years, and have found signs that there's a positive connection between the two. The studies suggest that religious involvement -- whether it's private or public -- is linked to things like better physical health, less depression and more happiness, said Jeff Levin, director of Baylor University's Program on Religion and Population Health.

But researchers have also found signs that people who attend services put on more weight. In the new study, which will be released Wednesday at an American Heart Association conference in Atlanta, researchers sought to follow people over time to see what happened to them. They examined a previous long-term study that tracked 2,433 people who were aged 20 to 32 in the mid-1980s.

Most of the participants were women, and 41 percent were black.

After adjusting their statistics to take into account factors such as race, the researchers found that 32 percent of those who attended services the most became obese by middle age, Feinstein said.

By contrast, only 22 percent of those who attended services the least became obese.

What might explain obesity among those who attend services regularly? There are plenty of theories.

Levin said one possibility is that those who attend services, along with activities such as Bible study and prayer groups, could be "just sitting around passively instead of being outside engaging in physical activity."

Also, he said, "a lot of the eating traditions surrounding religion are not particularly healthy; for example, constant feasts or desserts after services or at holidays -- fried chicken, traditional kosher foods cooked in schmaltz (chicken fat), and so on."

There's another question: Why might religious people be obese yet still have good health? The fact that fewer are smokers might help explain that, Feinstein said.

Whatever the case, he said, the study points to the role that places of worship could play in reducing obesity.

"They can become part of the solution," explained Dr. Daniel P. Sulmasy, a professor of medicine and ethics at the University of Chicago, perhaps by increasing awareness of obesity and holding health fairs.

"Pastors, especially those in poor neighborhoods, could champion programs for more fresh produce and less fast food in their neighborhoods," Sulmasy added.

More information

For more about obesity, visit the U.S. Centers for Disease Control and Prevention.