A total of 269 women were included in the analyses. The incidence of GDM was 13.9% in the intervention group and 21.6% in the control group ([95% CI 0.40-0.98%] P = 0.044, after adjustment for age, prepregnancy BMI, previous GDM status, and the number of weeks of gestation). Gestational weight gain was lower in the intervention group (-0.58 kg [95% CI -1.12 to -0.04 kg] adjusted P = 0.037). Women in the intervention group increased their leisure time physical activity more and improved their dietary quality, compared with the women in the control group.