Effects of total fibre or resistant starch-rich diets within lifestyle intervention in obese prediabetic adults

Starting from the evidence-based health benefits that resistant starch (RS) shows when added to the diet, our aim in this study was to evaluate the effects of increased fibre intake with two different levels of RS coming from regular daily consumed foods on normalization of glycaemia within lifestyle intervention in the population with risk factors for developing diabetes. Study included 47 overweight and obese men and women with disordered glucoregulation and dyslipidaemia, aged between 45-74, divided into RS and Fibre group. Participants were subjected to the lifestyle and dietary intervention with low-fat and high-fibre (> 25 g/day) diet for 12 months and were offered two different dietary advices aimed at increasing total fibre intake in Fibre group and at increasing RS intake in RS group. The intake of macronutrients and total fibre was similar between groups at the end of the study, but achieved RS intake was two times higher in the RS group. Decrease in total cholesterol and non-HDL-cholesterol was more pronounced in RS group in comparison with Fibre group (p = 0.010, p = 0.031, respectively), whereas in Fibre group, a more pronounced effect on glucoregulation was observed: significant fall in glycaemia after 2-h oral glucose tolerance test (7.93 vs 6.96 mmol/L, p = 0.034). At the end of the study, RS-rich diet failed to affect glycaemic control in prediabetic obese individuals in contrast to the regular fibre-rich diet, which indicated that fibre profile could be an important determinant of the effect of dietary intervention.