Examining the Effects of Diet on Health With an Online Program

Inclusion Criteria: 1. HbA1c 6.5%-9% at screening. 2. Aged 18 years old and older 3. BMI 25 and above. 4. Willing and able to participate in the interventions such as having sufficient control over their food intake. Must have the ability to make choices about the food they eat; cannot have a lifestyle in which they eat out most of their meals.) Exclusion Criteria: 1. Unable to provide informed consent. 2. Non English speaker. 3. No current use of insulin, no immediate plans to start or increase diabetic mediations, and no use of diabetes medications besides metformin. 4. A substance abuse, mental health, or medical condition that, in the opinion of investigators, will make it difficult for the potential participant to participate in the intervention. Such conditions may include: cancer, liver failure, unstable coronary artery disease, severe emphysema, binge eating disorder or history of binge eating disorder, bulimia or strong history of bulimia. 5. Previous use or recent changes in medications that can interfere with the measures used in the study: current use of insulin; use of systemic (oral or IV) corticosteroids in the 6 months prior to enrollment or severe autoimmune disorders or other conditions (e.g. rheumatoid arthritis, lupus), that are likely to require these medications; and initiation of new class of psychiatric medications in past 2 months. 6. Pregnant or planning to get pregnant in the next 12 months, breastfeeding or less than 6 months post-partum. 7. Current use of weight loss medications or supplements such as Alli or amphetamine-based drugs that are believed to have some effect on weight. 8. History of or planned weight loss surgery. 9. Vegan or vegetarian. The intervention diets are more challenging for vegan and vegetarian participants. 10. No or very limited internet access at a computer. Must be able to complete the online assessments and access the online class materials.