The Effects of Dairy Intake on Insulin Resistance: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

Nutrients. 2019 Sep 17;11(9):2237. doi: 10.3390/nu11092237.

Abstract

The incidence of type 2 diabetes mellitus (DM) has increased in the US over the last several years. The consumption of low-fat dairy foods has been linked with decreasing the risk of DM but studies have yet to show a clear correlation. We conducted a systematic review and meta-analysis of randomized clinical trials (RCTs) evaluating the effects of dairy intake on homeostatic model assessment of insulin resistance (HOMA-IR), waist circumference, and body weight. In MEDLINE and Embase, we identified and reviewed 49 relevant RCTs: 30 had appropriate data format for inclusion in the meta-analysis. Using the Review Manager 5 software, we calculated the pooled standardized mean differences comparing dairy dietary interventions to control for our outcomes of interest. For HOMA-IR (794 individuals), we found a mean difference of -1.21 (95% CI -1.74 to -0.67; p-value < 0.00001; I2 = 92%). For waist circumference (1348 individuals), the mean difference was -1.09 cm (95% CI 1.68 to -0.58; p-value < 0.00001; I2 = 94%). For body weight (2362 individuals), the dairy intake intervention group weighed 0.42 kg less than control (p-value < 0.00001; I2 = 92%). Our findings suggest that dairy intake, especially low-fat dairy products, has a beneficial effect on HOMA-IR, waist circumference, and body weight. This could impact dietary recommendations to reduce DM risk.

Keywords: dairy intake; diet; insulin resistance; low-fat dairy; waist circumference; weight loss.

Publication types

  • Meta-Analysis
  • Systematic Review

MeSH terms

  • Adult
  • Aged
  • Biomarkers / blood
  • Blood Glucose / metabolism*
  • Dairy Products*
  • Diabetes Mellitus, Type 2 / blood
  • Diabetes Mellitus, Type 2 / epidemiology
  • Diabetes Mellitus, Type 2 / physiopathology
  • Diabetes Mellitus, Type 2 / prevention & control*
  • Diet, Fat-Restricted*
  • Dietary Fats / administration & dosage*
  • Dietary Fats / metabolism
  • Energy Intake
  • Female
  • Humans
  • Insulin / blood*
  • Insulin Resistance*
  • Male
  • Middle Aged
  • Nutritive Value*
  • Randomized Controlled Trials as Topic
  • Recommended Dietary Allowances
  • Waist Circumference
  • Weight Loss
  • Young Adult

Substances

  • Biomarkers
  • Blood Glucose
  • Dietary Fats
  • Insulin