A whole-grain cereal-based diet lowers postprandial plasma insulin and triglyceride levels in individuals with metabolic syndrome

Nutr Metab Cardiovasc Dis. 2014 Aug;24(8):837-44. doi: 10.1016/j.numecd.2014.01.007. Epub 2014 Jan 28.


Background and aim: Until recently, very few intervention studies have investigated the effects of whole-grain cereals on postprandial glucose, insulin and lipid metabolism, and the existing studies have provided mixed results. The objective of this study was to evaluate the effects of a 12-week intervention with either a whole-grain-based or a refined cereal-based diet on postprandial glucose, insulin and lipid metabolism in individuals with metabolic syndrome.

Methods and results: Sixty-one men and women age range 40-65 years, with the metabolic syndrome were recruited to participate in this study using a parallel group design. After a 4-week run-in period, participants were randomly assigned to a 12-week diet based on whole-grain products (whole-grain group) or refined cereal products (control group). Blood samples were taken at the beginning and end of the intervention, both fasting and 3 h after a lunch, to measure biochemical parameters. Generalized linear model (GLM) was used for between-group comparisons. Overall, 26 participants in the control group and 28 in the whole-grain group completed the dietary intervention. Drop-outs (five in the control and two in the whole-grain group) did not affect randomization. After 12 weeks, postprandial insulin and triglyceride responses (evaluated as average change 2 and 3 h after the meal, respectively) decreased by 29% and 43%, respectively, in the whole-grain group compared to the run-in period. Postprandial insulin and triglyceride responses were significantly lower at the end of the intervention in the whole-grain group compared to the control group (p = 0.04 and p = 0.05; respectively) whereas there was no change in postprandial response of glucose and other parameters evaluated.

Conclusions: A twelve week whole-grain cereal-based diet, compared to refined cereals, reduced postprandial insulin and triglycerides responses. This finding may have implications for type 2 diabetes risk and cardiovascular disease.

Keywords: Cereal fiber; Glucose metabolism; Insulin metabolism; Lipids; Whole-grains.

Publication types

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

MeSH terms

  • Adult
  • Aged
  • Apolipoproteins A / blood
  • Apolipoproteins B / blood
  • Blood Glucose / metabolism
  • Cardiovascular Diseases / prevention & control
  • Cholesterol, HDL / blood
  • Cholesterol, LDL / blood
  • Diabetes Mellitus, Type 2 / prevention & control
  • Diet*
  • Edible Grain*
  • Fatty Acids, Nonesterified / blood
  • Female
  • Glucagon-Like Peptide 1 / blood
  • Glycemic Index
  • Humans
  • Insulin / blood*
  • Linear Models
  • Lipid Metabolism
  • Male
  • Metabolic Syndrome / blood*
  • Middle Aged
  • Nutrition Assessment
  • Patient Compliance
  • Postprandial Period*
  • Triglycerides / blood*


  • Apolipoproteins A
  • Apolipoproteins B
  • Blood Glucose
  • Cholesterol, HDL
  • Cholesterol, LDL
  • Fatty Acids, Nonesterified
  • Insulin
  • Triglycerides
  • Glucagon-Like Peptide 1