NEW YORK (Reuters) - Diet changes, exercise and other behavioral tactics do help obese adults shed some pounds with or without the help of medication, according to a study published Monday. In the new review, of 58 clinical trials, researchers found that behavioural programs helped obese people lose an average of 7 pounds more over 12 to 18 months, versus people who received no special therapy most of whom lost little to no weight. And the more intensive the program, the better, said lead researcher Dr. Erin S. LeBlanc of the Centre for Health Research at Kaiser Permanente in Portland, Oregon. On average, people who had 12 to 26 sessions in a comprehensive weight-loss program over one year lost 9 to 15 pounds. Comprehensive meant that a program offered a range of tactics such as exercise sessions, goal-setting and overcoming day-to-day barriers to keeping up a healthy lifestyle. And adding medication seemed to boost weight loss a bit, LeBlancs team found. Its estimated that one-third of U.S. adults are obese, and cutting those excess pounds is notoriously difficult. In trials that tested intensive behavioural therapy plus the weight-loss drug orlistat (Xenical), people lost an average of 11 to 22 pounds, versus 7 to 13 pounds with behavioural therapy alone.