Women with a history of gestational diabetes mellitus (GDM) have an increased risk of developing type 2 diabetes later in life. In our 2012 pilot study we created and tested a web-based lifestyle intervention program adapted from the NIH sponsored Diabetes Prevention Program (DPP), modified specifically for women with a recent history of GDM. This program, delivered in the first year postpartum, encouraged weight loss, dietary changes, and physical activity. The purpose of the current study, called Balance After Baby Intervention 2 (BABI-2), is to study a larger group of women with two years of follow-up. We will assess whether women assigned to the intervention group lose more weight and decrease their risk factors for type 2 diabetes.