We recently reported that in subjects with untreated type 2 diabetes, a 5-week diet of 30:30:40 carbohydrate:protein:fat ratio resulted in a significant decrease in 24-hour integrated glucose, total % glycohemoglobin and total cholesterol compared to a control diet of 55:15:30 carbohydrate:protein:fat given at the beginning of the 5 week period. Body weight was stable and insulin was unchanged. We now present data on other hormones and metabolites considered to be affected by dietary macronutrient changes. The test diet resulted in an elevated fasting plasma total IGF-1, but not growth hormone. Urinary free cortisol was increased. Serum renin and urinary aldosterone remained unchanged. Blood pressure was stable. Serum creatinine and uric acid were increased. Urinary microalbumin was decreased. Creatinine clearance, serum B₁₂, folate, homocysteine, TSH, and free T₄ were unchanged. Total T₃ was decreased. Plasma -amino nitrogen, urea nitrogen and serum albumin were increased. Urea production rate was increased such that a new steady-state was present. The calculated urea production rate accounted for 84% of protein ingested on the control diet but only 68% on the test diet, suggesting net nitrogen retention on the latter. The lack of negative effects, improved glucose control and a positive nitrogen balance suggest beneficial effects for subjects with type 2 diabetes at risk for loss of lean body mass. Nevertheless, the long-term effects and general applicability of the diet remain to be determined.