The US obesity epidemic is being transmitted to the next generation. Growing evidence suggests that both a mothers' weight at pregnancy onset, and excessive weight gain during pregnancy, are associated with increased risk of pregnancy-related complications such as gestational diabetes and pre-eclampsia, and an increased risk that her child will become obese and face obesity-related health issues in later life.

Currently, over one-third of reproductive-aged women in the U.S. are obese [body mass index (BMI) ≥ 30]. Our research team has shown that we can improve birth weight outcomes in babies of obese women who start a weight-management intervention program at 14 to 15 weeks of their pregnancy (soon after their first prenatal visit). However, organogenesis and metabolic programming begin early in the first trimester, well before the first prenatal visit. Therefore, waiting to address mothers' weight, physical activity, and diet quality until the first prenatal visit is not optimal. Given the need to reach overweight and obese women prior to pregnancy, and the Institute of Medicine's (IOM's) recent recommendation, based on observational studies, that women should reach a healthy weight before conceiving, this randomized clinical trial will evaluate a comprehensive preconception weight loss program.

The goals are to help overweight and obese women (BMI ≥ 27) who are considering pregnancy to adopt improved dietary and physical activity habits and lose weight prior to becoming pregnant, and then help them maintain those habits and prevent excessive weight gain during their pregnancy. We model this intervention after successful, frequent-contact interventions designed by ourselves and other investigators. We start with face-to-face counseling followed by frequent telephone counseling contacts. The expected outcomes for mothers include reduced pregnancy-related weight gain (primary) and lower weight at the start of pregnancy (secondary) and for babies, decreased risk of exceeding national norms for weight at birth (secondary).

Inclusion Criteria:

• Current Kaiser Permanente Northwest (KPNW) member
• Expects to be KPNW member for at least 2 more years
• Body Mass Index (BMI) ≥ 27
• Not currently pregnant
• Access to computer with Internet
• Completion of screening diet assessment
• English speaking

Exclusion Criteria:

• Taking medication (insulin or pills) for treatment of diabetes
• Gastrointestinal disease requiring special diet or medications (for example, ulcerative colitis, celiac sprue, phenylketonuria)
• Currently receiving treatment for cancer
• Renal disease (kidney disease requiring special diet or medication)
• History of bariatric surgery
• Use of prescription weight loss medications in the last three months
• Another household member already participating in the Prepare study

Any information from this study we present in reports or publications will not identify any individual.