Reducing protein in the diabetic diet.

Long-term protein intake may have pathogenic influence on development of late diabetic complications. A review of the latest results in insulin-dependent diabetic patients shows that short-term lowering of protein intake reduces the characteristic early glomerular hyperfiltration as well as microalbuminuria and proteinuria in diabetic nephropathy. A sustained beneficial effect on the progression rate of nephropathy may be achieved. Based on this evidence it is advisable to avoid the traditionally high protein intake in diabetes. We suggest a protein-controlled diet--with protein comprising 14 energy %--as a goal in uncomplicated diabetes. In patients with progressive albuminuria or proteinuria prescription of a low-protein diet with 10% protein should be considered as supplementation to antihypertensive treatment. At present we do not find sufficient evidence for suggesting an intake of 10% protein (corresponding approximately to recent recommendations on 0.8 g prot/kg body weight) also in uncomplicated diabetes. Both a 10 and 14% protein diet will differ somewhat from the diet of the background population and the present diet of many diabetic patients. Therefore the introduction of such diets requires a careful individualized diet therapy in which repetitive evaluation and estimation of compliance are performed. A reduction of protein intake to 10 energy % represents a profound diet intervention.