Inclusion Criteria:  Age ≥18 years; Delivered a baby at HUP or PAH within 3-12 months prior to study start; BMI ≥ 27 kg/m2 Diagnosis of one of the following medical conditions: chronic hypertension, gestational hypertension, preeclampsia, eclampsia, gestational diabetes, or diabetes mellitus (type 1 or 2) based on diagnosis codes in the EMR Has online access through smartphone or computer and has email address Ability to read and provide informed consent to participate in the study  Exclusion Criteria:  Delivered prior to 32 weeks gestation in the EMR Documentation of fetal demise or neonatal demise in the EMR Currently pregnant or planning to get pregnant within the next 5 months Does not speak English  Answers yes to any of the following questions:  Are you currently participating in any other weight loss or physical activity studies? Do you have any medical conditions or other reasons why you could not participate in a 16-week weight loss or physical activity program? Participants will be excluded after completing the run-in period if they do not complete the daily food log or their baseline BMI is < 27 kg/m2