(HealthScout). Cut just a few calories from your diet and you could cut your risk of diabetes in half. Or maybe more.

And while you're at it, your blood pressure may drop as well.

All it takes is to lose a pound a year, says Lynn L. Moore, MD, an assistant professor of medicine at Boston University and lead author of a recent study on weight loss and diabetes.

"There are substantial health benefits to a very modest weight loss, as long as the weight loss is sustained over time," Moore says.

"The people who were successful here didn't necessarily lose a lot of weight," she says. "They lost a small amount over a longer time."

Obese middle-age adults who lost as little as a pound a year reduced their risk of adult-onset diabetes (type 2) by as much as 62 percent, she says. Results of the study appeared in a recent issue of the journal Epidemiology.

To lose a pound a year, Moore says, you simply need to cut 10 calories a day -- less than the amount in a couple of potato chips. But the key is keeping the weight off.

The researchers examined data on 618 middle-age men and women who either had lost weight or had kept their weight stable over a 16-year period. All participated in the Framingham Heart Study, a long-term examination of more than 5,000 residents of the Massachusetts city that began in 1948.

For heavier people, bigger payoffs
People who lost a pound a year for eight years, then kept the weight off for eight more years, reduced their risk of diabetes between 37 percent and 62 percent, depending on how heavy they were to begin with, the study says.

The heavier the participants were at the start, the greater their benefit from the small weight loss.

Those who continued to lose a pound a year for all 16 years reduced their diabetes risk even more -- in some cases by as much as 82 percent, according to the study results.

"The point of it being a very modest, gradual weight loss is important," says Dr. Robert Sherwin, president of the American Diabetes Association and a professor at the Yale University School of Medicine.

"People focus too much on weight loss from the perspective of appearance," Sherwin says. "If you lose a pound or two a year and you're substantially overweight, that's not going to have much of an impact on your appearance. But it can have a positive effect on your health."

The typical American adult gains at least a pound or two each year during middle age, Moore says.

"So for people who are entering those middle adult years, the thing to do is not allow yourself to gain that pound or two a year," she says. "People lose control before they realize it."

Nearly 15 million Americans have adult-onset diabetes. But diabetes is only one of the many diseases that can be made worse by obesity, which both Moore and Sherwin call one of the biggest challenges facing the American medical community today.

"It's a major public health problem in this country," Moore says. "The fact that our children are much more obese than they were 20 years ago is a substantial problem. These children are going to be developing the chronic diseases of adulthood at a much earlier age."

Diabetes' staggering cost
Sherwin says diabetes already costs society $100 billion a year. "If we keep on at the rate we're going, in 25 years it will be a trillion [dollars]," he says.

But losing weight doesn't stave off just diabetes.

Losing a pound a year also can significantly lower the risk of high blood pressure, Moore says.

People in an earlier study she conducted who lost a pound a year for only four years -- but who kept the weight off for four more years -- lowered their risk of high blood pressure by about 25 percent, Moore says. "

Just think about that a little bit," says Dr. Robert H. Eckel, chairman of the nutrition committee of the American Heart Association. "That's important information."

"The motto here is, keep weight maintenance as a goal," Eckel says.