Evaluating a small change approach to preventing long term weight gain in overweight and obese adults--Study rationale, design, and methods.

Despite the rapid rise in obesity worldwide, few strategies have been effective in treating this epidemic. An emerging strategy is to focus on preventing excessive weight gain rather than weight reduction. The proposed intervention, small change approach (SCA), is an innovative weight gain prevention strategy in which individuals monitor their usual nutrition and physical activity patterns and then make modest but sustainable alterations through behavioral intervention techniques (self-regulation, goal setting) enough to reduce overall energy balance by 100 to 200 kcal per day (e.g., reduce caloric intake by 100 kcal per day and/or increase daily step count by 2000 steps (100 kcal) per day). The primary aim of the trial is to determine whether small changes in energy expenditure and/or energy intake prevent weight gain in overweight and obese men and women long-term. The pre-specified primary and secondary assessments are at 2 and 3 years post-randomization respectively. The primary outcome is change in body weight. Secondary outcomes include body composition variables (adipose tissue distribution and lean mass distribution) and cardiorespiratory fitness (VO2peak). We randomized 320 primarily White (n=305) overweight and obese men and women to one of 2 conditions: 1) usual care (UC), 2) small change approach (SCA). Participant involvement in the study is 3 years; 2 year intervention with a 1 year follow-up. Our study findings will indicate whether there is value in clinicians adopting a SCA to lifestyle counseling for their patients who are overweight and obese.