Baseline obesity status modifies effectiveness of adapted diabetes prevention program lifestyle interventions for weight management in primary care.

OBJECTIVE: To examine whether baseline obesity severity modifies the effects of two different, primary care-based, technology-enhanced lifestyle interventions among overweight or obese adults with prediabetes and/or metabolic syndrome.

PATIENTS AND METHODS: We compared mean differences in changes from baseline to 15 months in clinical measures of general and central obesity among participants randomized to usual care alone (n = 81) or usual care plus a coach-led group (n = 79) or self-directed individual (n = 81) intervention, stratified by baseline body mass index (BMI) category.

RESULTS: Participants with baseline BMI 35+ had greater reductions in mean BMI, body weight (as percentage change), and waist circumference in the coach-led group intervention, compared to usual care and the self-directed individual intervention (P < 0.05 for all). In contrast, the self-directed intervention was more effective than usual care only among participants with baseline BMIs between 25 ≤ 35. Mean weight loss exceeded 5% in the coach-led intervention regardless of baseline BMI category, but this was achieved only among self-directed intervention participants with baseline BMIs <35.

CONCLUSIONS: Baseline BMI may influence behavioral weight-loss treatment effectiveness. Researchers and clinicians should take an individual's baseline BMI into account when developing or recommending lifestyle focused treatment strategy. This trial is registered with ClinicalTrials.gov NCT00842426.