LoBAG30 Diet in Patients on Metformin

Subjects will ingest a control diet (55% carbohydrate (CHO), 15% protein, 30% fat) or a LoBAG30 diet (30% CHO, 30% protein, 40% fat) in a parallel design with block randomization in pairs of two. Subjects will return to the study center twice each week while on the diets to have blood glucose, glycohemoglobin, lactate, weight and blood pressure measured, and to have urine assayed for urea and creatinine. At the beginning and end of the 5 week study period, the subjects will be admitted to the study center for 28 hours during which time blood will be drawn for 24 hour profiles of glucose, insulin, other hormones and several metabolites. For those subjects randomized to the LoBAG30 arm of the study, the control diet will be given during the first 24 hour study period; the assigned diet will be given at the end of the 5 week period.