Limiting weight gain in overweight and obese women during pregnancy to improve health outcomes: a randomised trial.

Women randomised to the Dietary and Lifestyle Advice Group will receive a comprehensive intervention to limit weight gain in pregnancy that includes a combination of dietary, exercise and behavioural strategies, delivered by a research dietician and trained research assistants. Women will be provided with dietary advice consistent with current Australian dietary standards, that maintains a balance of carbohydrates, fat and protein. Women will be encouraged to reduce their intake of foods high in refined carbohydrates and saturated fats, while increasing their intake of fibre, and promoting consumption of two serves of fruit and five serves of vegetables each day. Exercise advice will focus on encouraging women to adopt a more active lifestyle, primarily by increasing the amount of walking. Tailoring of the intervention will be informed by stage theories of health decision making that propose that individuals progress through a series of cognitive phases when undertaking behavioural change. Initially, there will be a 1 hour planning session with a research dietician, in which women are provided with written dietary and activity information, an individual diet and physical activity plan, a food and activity diary, recipe book and example menu plans. Women will be encouraged to set achievable goals for dietary and exercise change, supported to make these lifestyle changes and to self-monitor their progress. Additionally, women will be encouraged to identify potential barriers and enablers to facilitate the implementation of their goals. This information will be reinforced during subsequent inputs at regular intervals during pregnancy, provided by the research dietician (at 28 weeks’ gestation) and trained research assistants (via telephone call at 22, 24, and 32 weeks’ gestation and a face-face visit at 36 weeks’ gestation).