One-year weight losses in the Tianjin Gestational Diabetes Mellitus Prevention Program: A Randomized Clinical Trial.

Aims: To report the weight loss findings after the first year of a lifestyle intervention trial among women with gestational diabetes mellitus (GDM). Methods: A total of 1180 women with GDM were randomly assigned (1: 1) to receive a 4-year lifestyle intervention (intervention group, n = 586) or standard care (control group, n = 594) between August 2009 and July 2011. Major elements of the intervention included 6 face-to-face sessions with study dieticians and two telephone calls in the first year, and two individual sessions and two telephone calls in each subsequent year. Results: Among 79% of participants who completed the year 1 trial, mean weight loss was 0.82 kg (1.12% of initial weight) in the intervention group and 0.09 kg (0.03% of initial weight) in the control group (P=.001). In a prespecified subgroup analysis of people who completed the trial, weight loss was more pronounced in women who were overweight (body mass index = 24 kg/m(2)) at baseline: mean weight loss 2.01 kg (2.87% of initial weight) in the intervention group and 0.44 kg (0.52% of initial weight) in the control group (P<.001). Compared with those in the control group, women in the intervention group had a greater decrease in waist circumference (1.76 cm vs 0.73 cm; P=.003) and body fat (0.50% vs 0.05% increase; P=.001). Conclusion: The 1-year lifestyle intervention led to significant weight losses after delivery in women who had GDM, and the effect was more pronounced in women who were overweight at baseline.