SEATTLE — Regular yoga practice may help prevent middle-age spread in normal-weight people and may promote weight loss in those who are overweight, according to a study in the July/August issue of Alternative Therapies in Health and Medicine.

Funded by the National Cancer Institute, the study involved 15,500 healthy, middle-aged men and women who were asked to complete a written survey recalling their physical activity (including yoga) and weight history between the ages of 45 and 55. The study measured the effect of yoga on weight change, independent of other factors such as diet or other types of physical activity. For the study, regular yoga practice was defined as practicing at least 30 minutes once a week for four or more years.

The researchers found that between the ages of 45 and 55, most people gained about a pound a year, which is a common pattern as people age and do not adjust their caloric intake to their declining energy needs.

However, men and women who were of normal weight at age 45 and regularly practiced yoga gained about 3 fewer pounds during that 10-year period than those who didn't practice yoga, said Alan R. Kristal, Dr.P.H., the study's lead author.