Fit After Baby: Increase Postpartum Weight Loss in Women

Eligibility Details: Inclusion Criteria: 1. Age 18-45 2. Postpartum Body Mass Index (BMI): 26- 45 kg/m2 (≥24 for Asians) 3. Positive history of one or more of the following complications in most recent singleton or twin pregnancy: 1. Gestational diabetes mellitus (by Carpenter-Coustan criteria, IADPSG (International Association of the Diabetes and Pregnancy Study Groups) criteria, or a documented clinical diagnosis). Women with a glucose value >200 mg/dL after a 50-g glucose challenge test at >12 weeks gestation will also be included. 2. Preeclampsia (high blood pressure and proteinuria diagnosed after 20 weeks gestation) 3. Gestational hypertension (new hypertension diagnosed after 20 weeks without proteinuria) 4. Pre-term delivery (32-37 weeks) 5. Small for gestational age (<10th percentile for gestational age) 4. Access to and be willing to use a wi-fi enabled iPhone (5 or higher) or iPod (5 or higher). 5. Capable of providing informed consent 6. Between 4 weeks and 16 weeks after delivery Exclusion criteria include: 1. Personal history of Type 1 or 2 diabetes 2. Personal history of breast cancer or any other type of cancer other than a basal cell skin cancer; 3. Personal history of major chronic illness all to be assessed by the study physician for ability to participate, including: 1. cardiovascular disease (coronary artery disease, congestive heart failure, valvular heart disease, stroke, transient ischemic attack, or intermittent claudication), 2. kidney disease affecting kidney function severe enough to affect participation, 3. liver disease affecting liver function severely enough to affect participation, 4. venous or arterial thromboembolic disease, 5. untreated adrenal insufficiency, 6. depression requiring hospitalization within the past 6 months, or 7. non-pregnancy related illness requiring overnight hospitalization in the past 6 months; 4. Underlying disease/treatment that might interfere with participation in/completion of the study (e.g. significant gastrointestinal conditions, major psychiatric disorders affecting the ability to participate, and others at the discretion of the study clinician); 5. Re-current pregnancy; 6. Diagnosis of diseases associated with glucose metabolism; 7. Current or planned participation in a commercial weight loss program (i.e. Jenny Craig) over the duration of the study; 8. Previous or planned bariatric surgery; 9. Taking certain prescription medications including 1. high dose glucocorticoids, 2. atypical antipsychotics associated with weight gain (such as risperdal (risperidone), clozapine (clozaril), olanzapine (zyprexa), quetiapine (seroquel), etc.) or 3. weight loss medications including prescription (Qsymia, phentermine, topiramate, Belviq, Contrave, Saxenda, Orlistat), or non-prescription (Alli) medications; 10. Taking metformin or other medications known to affect glucose metabolism; 11. Other active medical problems detected by examination or laboratory testing, at the discretion of the physician; 12. Any fasting blood glucose > 126 mg/dl, any HbA1c at or above 6.5%, or any plasma glucose >200 mg/dl during the first trimester.