There is not enough evidence to recommend any intervention for preventing excessive weight gain during pregnancy, due to the significant methodological limitations of included studies and the small observed effect sizes. More high-quality randomised controlled trials with adequate sample sizes are required to evaluate the effectiveness of potential interventions.
Effect of lifestyle intervention on dietary habits, physical activity, and gestational weight gain in obese pregnant women: a randomized controlled trial.
Maternal obesity and excessive gestational weight gain (GWG) are major short- and long-term risk factors for maternal and fetal complications.
                The objective was to study whether a lifestyle intervention based on a brochure or on active education can improve dietary habits, increase physical activity (PA), and reduce GWG in obese pregnant women.
                In this randomized controlled trial, 195 white, obese pregnant women [age: 29 + or - 4 y; body mass index (in kg/m(2)); 33.6 + or - 4.2] were randomly assigned into 3 groups: a group that received nutritional advice from a brochure, a group that received the brochure and lifestyle education by a nutritionist, and a control group. Nutritional habits were evaluated every trimester through 7-d food records. PA was evaluated with the Baecke questionnaire.
                Energy intake did not change during pregnancy and was comparable in all groups. Fat intake, specifically saturated fat intake, decreased and protein intake increased from the first to the third trimester in the passive and active groups compared with an opposite change in the control group. Calcium intake and vegetable consumption increased during pregnancy in all groups. PA decreased in all groups, especially in the third trimester. No significant differences in GWG and obstetrical or neonatal outcome could be observed between the groups.
                Both lifestyle interventions improved the nutritional habits of obese women during pregnancy. Neither PA nor GWG was affected.