Effects of a 3‐day low‐fat diet on metabolic control, insulin sensitivity, lipids and adipocyte hormones in Norwegian subjects with hypertriacylglycerolaemia and type 2 diabetes

Abstract

The metabolic and hormonal impact of rapid dietary changes in type 2 diabetes has not been clarified. The objective of this study was to test whether a short‐term, low‐fat diet affected metabolic control, insulin sensitivity, lipids and adipocyte hormones in patients with type 2 diabetes with hypertriacylglycerolaemia. Nineteen outpatient subjects (10 M, 9 F) with type 2 diabetes and triacylglycerols >2.2 mmol/L at screening were included in the study. Dietary intake was assessed by weighing during two periods of 3‐day baseline diet followed by a 3‐day low‐fat dietary intervention. The two periods of baseline diet did not differ with respect to relevant variables during intervention. Subjects were advised to increase fibre‐rich and low‐fat foods and to decrease intake of visible fat in an isoenergetic manner. The percentage of energy from fat was reduced from 39 to 22 (p<0.0001), median values. Daytime blood glucose did not change and fasting insulin and fasting glucose to insulin ratios were unaffected. Total cholesterol decreased from 6.3 to 6.2 mmol/L (p<0.005), high‐density lipoprotein cholesterol from 1.13 to 1.10 mmol/L (p<0.048) and the ratio of n‐6 to n‐3 fatty acids in phospholipids from 2.5 to 1.9 (p<0.003). Concentrations of leptin decreased from 12.1 to 9.9 ng/mL (p<0.005) and adiponectin increased from 8.6 to 10.5 μg/mL (p<0.024). The effect on leptin was confined to women. A low‐fat diet intervention for 3 days in insulin‐resistant type 2 diabetes affects lipid, adiponectin and leptin levels but fails to improve insulin sensitivity and metabolic control.