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 self-report
* Prior or planned bariatric surgery
* Have significant renal disease or dysfunction defined as Estimated glomerular filtration rate (eGFR)\<45
* Have significant hepatic dysfunction \[Aspartate aminotransferase (AST)/Alanine transaminase (ALT) ≥ 2 x upper limit of normal (ULN) or reported liver disease\]
* Self-reported average consumption of \> 14 alcoholic drink per week
* Currently enrolled or planned to enroll in weight loss program
* Hemoglobin \<9 g/dl
* Platelet count \<100
* White blood cell count (WBC) \<2.5
* Plans to relocate from the area within one years
* Use of prescription weight loss medication(s) (e.g., lorcaserin, topiramate/phentermine, phentermine, liraglutide, and bupropion/naltrexone), including off label use of drugs for weight loss or over-the-counter weigh loss medications such as Orlistat within the past 6 months.