The earliest signs of renal impairment in the diabetic patient traditionally marked the onset of an era of frustration for both physician and patient. Aside from meticulous control of hypertension, there was little to do to alter the inexorable course to dialysis or transplantation. However, if the recent reports touting the benefits of low-protein diets are correct, all of this may soon change; these diets may delay or prevent end-stage renal insufficiency. The question is whether these diets are safe as well as efficacious.The diabetic patient is of special concern. These diets will be superimposed on existing abnormalities in insulin-mediated processes. Even subtle changes in substrate metabolism can be expected to have a profound cumulative impact over years of treatment. Our ability to detect evidence of early nephropathy makes it tempting to apply this therapy for relatively long periods.Low-protein diets, as they are currently formulated, are composed of unstandardized and variable combinations of carbohydrate (CHO), fat, and protein. There is no agreement on the degree of protein reduction or optimum ratios of complex to simple CHO, unsaturated to saturated fat, and biologically high-quality to lowquality protein. Thus, whereas these diets may be the Creatinine 1 (JLM = 0.011 mg/dlCreatinine clearance 1 ml/s = 60 ml/min