Weight gained during pregnancy is referred to as gestational weight gain (GWG). Excess GWG is a widespread problem that occurs in 55-75% of Canadian women who enter pregnancy overweight or obese (a group that represents over 50 % of all pregnant women) and about 40% women of normal weight. Excess GWG is associated with complications of pregnancy, such as post-partum weight retention, type 2 diabetes, elevated fats in the blood, and high blood pressure and may also lead to problems with the health of the newborn child. Our research aims to find ways to control GWG by developing new and practical approaches to diet and exercise targeted to overweight pregnant women that hold promise of improving their health both during pregnancy and thereafter. The experimental intervention is a diet of higher protein provided by dairy foods combined with an exercise program modified to the abilities of overweight pregnant women; and the control is the usual advice given by their primary care providers, information on healthy pregnancy from Health Canada, and a focus group session exploring women's experiences with exercise, nutrition, and gestational weight gain. The results of this study will allow us to design future large clinical studies in all pregnant women to help control the weight gain in all pregnant women.

This will be a 2-arm randomized 1-site trial. Recruitment will be within the community care clinics by poster and flyer advertisements.

Primary research question: Among pregnant women, does introducing a structured and monitored nutrition and exercise program (treatment) in early pregnancy compared with Usual Prenatal Care (control) increase the likelihood of attaining gestational weight gain within the Institute of Medicine (IOM) guidelines over the pregnancy period?

Experimental and Control groups: Both groups of mothers and their health care providers will be given the Health Canada materials on "Healthy Weight Gain during Pregnancy", "Eating Well with Canada's Food Guide" and the "Pregnancy Weight Gain Calculator". Baseline information will be recorded for eligible and consenting women after which they will be randomized to Experimental or Control group. Nutrition intake, physical measures and physical activity will be recorded at baseline, 26-28 weeks and 36-38 weeks of gestation and 6 months post partum in the same manner for both groups. All mothers will receive the study promotional materials and small incentives. Also, all mothers will be followed by their primary care provider and have usual access to Public Health.

Inclusion Criteria:

• Healthy pregnant females > 18 years of age with singleton pregnancies (either nulliparous or multiparous); less than 20 weeks gestation; pre-pregnancy BMI of >25 and < 40 kg/m2 (owing to the fact that severe obesity with BMI> 40 may have limitations with respect to physical activity); plans to deliver at a Hamilton Health Sciences, St. Joseph's Healthcare Hamilton, Joseph Brant Hospital or by home birth but willing to attend research visits at the McMaster University Medical Centre site; approval of primary care provider; and able to provide signed informed consent.

Exclusion Criteria:

• Unable to understand some English; currently breastfeeding previous child; pregnancy resulting from in vitro fertilization; known contraindications to exercise as recommended by the Canadian clinical practice guidelines for pregnancy; severe chronic gastrointestinal diseases or conditions; refusal to consume dairy foods due to intolerance or dislike; any significant heart, kidney, liver or pancreatic diseases; pre-existing diabetes; or a depression score above 13 on the validated Edinburgh Depression scale as that is indicative of severe depression and should be referred for treatment; currently smoking.