Diet, insulin secretion and insulin sensitivity--the Dose-Responses to Exercise Training (DR's EXTRA) Study (ISRCTN45977199)

Br J Nutr. 2014 Nov 14;112(9):1530-41. doi: 10.1017/S0007114514002426. Epub 2014 Sep 18.


Intakes of saturated fat (SF) and dietary fibre, body mass and physical activity are all associated with the incidence of type 2 diabetes mellitus. Their relative importance for the maintenance of normal glucose metabolism is not fully known. In a population-based sample of 1114 individuals, aged 58-78 years, dietary intakes were assessed by 4 d food records and cardiorespiratory fitness as maximal oxygen uptake. Insulin secretion, insulin sensitivity, the early-phase disposition index (DI30) and the total disposition index (DI120) were assessed based on an oral glucose tolerance test. Linear associations were modelled using linear regression. Combined effects were studied by introducing SF and fibre intakes, as well as cardiorespiratory fitness and waist circumference (WC) as dichotomised variables in general linear models. Intakes of dietary fibre and whole-grain bread were positively associated with insulin sensitivity, independent of physical fitness and WC. In women, dietary fibre intake was also positively associated with DI30. The negative association of high WC with DI30 was attenuated by a combination of low SF intake and high cardiorespiratory fitness. In conclusion, dietary fibre and a combination of low SF intake and high cardiorespiratory fitness may contribute to the maintenance of normal glucose metabolism, independent of WC.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Blood Glucose / analysis
  • Body Mass Index
  • Bread
  • Diet Records
  • Diet*
  • Dietary Fats / administration & dosage
  • Dietary Fiber / administration & dosage
  • Edible Grain
  • Exercise Test
  • Exercise*
  • Fasting
  • Female
  • Finland
  • Glucose Tolerance Test
  • Humans
  • Insulin / metabolism*
  • Insulin Resistance*
  • Insulin Secretion
  • Male
  • Middle Aged
  • Oxygen Consumption
  • Physical Fitness
  • Waist Circumference


  • Blood Glucose
  • Dietary Fats
  • Dietary Fiber
  • Insulin

Associated data

  • ISRCTN/ISRCTN45977199