Apolzan JW, et al. -

Researchers wanted to find reliable predictors of long-term weight loss (LTWL) because they could help improve weight management. Out of the 3,234 randomly assigned to metformin, intensive lifestyle intervention (ILS), or placebo, 1,066 lost at least 5% of baseline weight in the first year and they were followed for 15 years. After 1 year, 28.5% of participants in the metformin group, 62.6% of the ILS group, and 13.4% in the placebo group had lost at least 5% of their weight. The mean weight loss relative to baseline sustained between years 6 and 15 was 6.2% in the metformin group, 3.7% in the ILS group, and 2.8% in the placebo group, following the treatment phase. Overall, the authors concluded that those who were originally assigned randomly to metformin had the greatest loss in years 6 to 15 when looking at the people with a weight loss of at least 5% after 1 year. The most consistent predictors of LTWL maintenance across all groups were older age and the amount of weight initially lost.