A low‐fat diet improves peripheral insulin sensitivity in patients with Type 1 diabetes

Abstract

Aims To compare the effects on insulin sensitivity, body composition and glycaemic control of the recommended standard weight‐maintaining diabetes diet and an isocaloric low‐fat diabetes diet during two, 3‐month periods in patients with Type 1 diabetes. Methods Thirteen Type 1 patients were included, of whom 10 completed the cross‐over study. Ten non‐diabetic, matched control subjects were also examined. Body composition was estimated by dual‐energy X‐ray absorptiometry (DXA) whole‐body scanning, diet intake was monitored by 7‐day dietary record and insulin sensitivity was measured by the insulin clamp technique at baseline and after each of the diet intervention periods. Results On an isocaloric low‐fat diet, Type 1 diabetic patients significantly reduced the proportion of fat in the total daily energy intake by 12.1% (or −3.6% of total energy) as compared with a conventional diabetes diet (P = 0.039). The daily protein and carbohydrate intake increased (+4.4% of total energy intake, P = 0.0049 and +2.5%, P = 0.34, respectively), while alcohol intake decreased (−3.2% of total energy intake, P = 0.02). There was a significant improvement in insulin sensitivity on the isocaloric, low‐fat diet compared with the standard diabetes diet [7.06 ± 2.16 mg/kg/min (mean ± sd) vs. 5.52 ± 2.35 mg/kg/min (P = 0.03)]. However, insulin sensitivity remained 33% lower than in the control subjects (P = 0.021). No significant changes occurred in body weight or body composition. Glycated haemoglobin rose during both diet intervention periods (P = 0.18), with no difference between the two diets. Conclusions Change to an isocaloric, low‐fat diet in Type 1 diabetic patients during a 3‐month period resulted in significant improvement in insulin sensitivity without improvement in glycaemic control. However, insulin sensitivity remained 33% lower than in control subjects. Diabet. Med. (2006)