Survivorship Promotion In Reducing IGF-1 Trial

Inclusion Criteria: * Women and men ages 18 or older * Have been previously diagnosed with a malignant solid tumor, completed their required surgical, and/or chemotherapy and/or radiation curative intent therapy at least three months prior to enrollment, and have an anticipated treatment-free life span of 12 months or longer. Chemoprophylaxis with tamoxifen or aromatase inhibitors for breast cancer in women and anti- Luteinizing hormone-releasing hormone (LHRH) therapy for prostate cancer in men will be permitted. * Have a BMI of 25 kg/m\^2 or greater and weight \<=400 lbs. * Willingness to accept randomization to each of the three arms * Willingness to change diet, physical activity, and weight * Regular access to computer with a reliable Internet connection * Ability to send and receive emails * Ability to complete online forms * Access to phone * Willingness to provide written informed consent Exclusion Criteria: * Women who are breastfeeding, pregnant, or planning pregnancy within the next year * Medication-treated diabetes * Fasting blood glucose \>=200 mg/dL, or fasting blood glucose \>=126 and \<200 mg/dL and HbA1C \>=7% * Current or prior regular use of metformin within the past 3 months * Uncontrolled concurrent medical condition likely to limit compliance with the study interventions * Received any chemotherapy (unless anti-hormonal therapy) and/or radiation three months or less prior to the proposed intervention date * Have a prior history of lactic acidosis by …