Two-year follow-up of a postpartum weight loss intervention: Results from a randomized controlled trial

We recently reported that a 12-week diet intervention among postpartum women produced a weight loss of 12% after 1 year, compared to 5% in controls. Here, we present 2-year results after 1 year of unsupervised follow-up. In total, 110 women with a self-reported body mass index of ≥27 kg/m² at 6-15-week postpartum were randomized to diet group (D-group) or control group (C-group). D-group received a 12-week diet intervention by a dietitian followed by monthly e-mails up to the 1-year follow-up. C-group received a brochure on healthy eating. No contact was provided from 1 to 2 years to either group. Eighty-nine women (81%) completed the 2-year follow-up. Median (1st; 3rd quartile) weight change from 0 to 2 years was -6.9 (-11.0; -2.2) kg in D-group and -4.3 (-8.7; -0.2) kg in C-group. There was no group by time interaction at 2 years (p = .082); however, when women with a new pregnancy between 1 and 2 years were excluded, the interaction became significant (-8.2 vs. -4.6 kg, p = .038). From 1 to 2 years, women in D- and C-group gained 2.5 ± 5.0 kg and 1.1 ± 4.4 kg, respectively (p = .186). Women who gained weight from 1 to 2 years reported a decrease in self-weighing frequency compared to women who maintained or lost weight (p = .008). Both groups achieved clinically relevant 2-year weight loss, but the significant between-group-difference observed at 1 year was not maintained at 2 years in the main analysis. However, when women with a new pregnancy between 1 and 2 years were excluded, a significant weight loss effect was observed also at 2 years.