Context: There are insufficient data on the long-term, nonsurgical, nonpharmacologic treatment of obesity.
Objective: To determine changes in weight over 5 years in participants enrolled between April 1, 2007, and December 31, 2014, in a medically supervised weight management program at Kaiser Permanente Northern California Medical Centers. The program consisted of 3 phases: Complete meal replacement for 16 weeks; transition phase, 17 to 29 weeks; and lifestyle maintenance phase, 30 to 82 weeks.
Design: Retrospective observational study of 10,693 participants (2777 available for analysis at 5 years); no comparator group.
Main outcome measures: Average change in weight from baseline to follow-up.
Results: Average age was 51.1 (standard deviation = 12.4) years, and 72.8% were women. Average baseline weight in the entire cohort was 112.9 kg (standard error [SE] = 0.23). Weight (kg) significantly changed over time: 4 months, -17.3 (SE = 0.12); 1 year, -14.2 (SE = 0.12); 2 years, -8.6 (SE = 0.14); 3 years, -6.9 (SE = 0.17); 4 years, -6.5 (SE = 0.16), and 5 years, -6.4 (SE = 0.29); p < 0.0001). In those with 5-year follow-up, weight loss between 5.0 and 9.9% below baseline occurred in 16.3% (SE = 0.004, 95% CI = 15.3% - 17.2%) and weight loss of 10.0% or more of baseline occurred in 35.2% (SE = 0.01, 95% CI = 33.6% - 36.7%).
Conclusion: The average weight change of obese adults who participated in a medically supervised weight management program, with available 5-year data, was a statistically and clinically significant 5.8% weight loss from baseline.