2. 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 or that may need immediate changes in medical management that will affect study outcome measures. Such conditions may include cancer, liver failure, renal failure, untreated hypo or hyperthyroidism, or history of serious bulimia. Some other serious medical conditions that may alter key study outcomes or require other important diet modifications, including untreated hypothyroidism, renal failure, cirrhosis, and conditions requiring oral or parenteral glucocorticoid treatment.