July 5 (HealthDay News) -- Weight-loss programs that include dietary counseling help dieters shed six percent of body weight more each year, according to a new study. For most people, that translates into a loss of 10 to 15 pounds, researchers say.

The team at the Tufts University School of Medicine, Boston, analyzed 46 studies focused on weight loss. They compared data from almost 6,400 people whose programs included dietary counseling and almost 5,500 people who were not in these types of programs.

Programs with frequent meetings and calorie restrictions resulted in more successful weight loss over time, according to the study, which is published in he Annals of Internal Medicine.

Three years later, most people maintained half the overall weight loss. However, by the end of five years, all participants had regained the weight.

"We did not know how much weight people lost on average through weight loss programs or how long it took to gain it back. This study shows that lifestyle change needs to be for the long-term," study author Dr. Michael L. Dansinger, a physician at Tufts-New England Medical Centers Division of Endocrinology, Diabetes and Metabolism, said in a prepared statement.

"Moderate weight loss -- 10 to 20 pounds -- has a dramatic effect on most of the medical problems caused by obesity," he added. "Diabetes, cholesterol, blood pressure and stroke risk all appear to be nicely reduced by a moderate amount of weight loss."

According to the Centers for Disease Control and Prevention, one in three adults in the United States is obese. Obesity contributes to chronic diseases such as diabetes and heart disease.