Using Mental Imagination to Prevent Excessive Gestational Weight Gain in Overweight and Obese Pregnant Women

Inclusion Criteria: * Participants must be pregnant women ≤ 13 week-gestation with a single fetus as assessed by ultrasound. * Participants must also have self-reported pre-pregnancy body mass index (BMI) of 25.0-45.0 kg/m2 and height (height and weight to compute body mass index). * Ability to read and speak English, * Age of 18-45 years, * Access to a working smart phone with unlimited text messaging, * Access to internet, * Receipt of prenatal care from our collaborating clinics and plan to deliver the baby at The Ohio State University (OSU) Wexner Medical Center, * Resident of Franklin Count, * Committed to the 20-week intervention. Exclusion Criteria: * Self-reported history of ≥ 3 miscarriages, * Planned termination of the pregnancy, * Diagnosed hypertension and/or type 1 or 2 diabetes, * History of or current diagnosis of an eating disorder, * Serious current physical disease (e.g., renal disease or cancer), * Past bariatric surgery, * Current or history of substance abuse in the past 6 months, * Current treatment for a serious psychological disorder (e.g., schizophrenia and bipolar disorder), * Contraindications to walking, * Consented women will become not eligible to participate in the study if they are not randomized by 16-week 6 days gestation. This is because the study intervention starts ≤ 17 weeks gestation. * Women will become not ineligible for participation if they did not complete the baseline data.