A Plant-Based Dietary Intervention Improves Beta-Cell Function and Insulin Resistance in Overweight Adults: A 16-Week Randomized Clinical Trial

Nutrients. 2018 Feb 9;10(2):189. doi: 10.3390/nu10020189.

Abstract

The aim of this study was to test the effect of a plant-based dietary intervention on beta-cell function in overweight adults with no history of diabetes. Participants (n = 75) were randomized to follow a low-fat plant-based diet (n = 38) or to make no diet changes (n = 37) for 16 weeks. At baseline and 16 weeks, beta-cell function was quantified with a mathematical model. Using a standard meal test, insulin secretory rate was calculated by C-peptide deconvolution. The Homeostasis Model Assessment (HOMA-IR) index was used to assess insulin resistance while fasting. A marked increase in meal-stimulated insulin secretion was observed in the intervention group compared with controls (interaction between group and time, Gxt, p < 0.001). HOMA-IR index fell significantly (p < 0.001) in the intervention group (treatment effect -1.0 (95% CI, -1.2 to -0.8); Gxt, p = 0.004). Changes in HOMA-IR correlated positively with changes in body mass index (BMI) and visceral fat volume (r = 0.34; p = 0.009 and r = 0.42; p = 0.001, respectively). The latter remained significant after adjustment for changes in BMI (r = 0.41; p = 0.002). Changes in glucose-induced insulin secretion correlated negatively with BMI changes (r = -0.25; p = 0.04), but not with changes in visceral fat. Beta-cell function and insulin sensitivity were significantly improved through a low-fat plant-based diet in overweight adults.

Keywords: beta-cell function; diabetes; diet; nutrition; vegan.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Absorptiometry, Photon
  • Adiposity
  • Adult
  • Aged
  • Body Mass Index
  • Diet, Fat-Restricted*
  • Diet, Reducing*
  • Diet, Vegan*
  • District of Columbia
  • Energy Intake
  • Female
  • Humans
  • Insulin / blood
  • Insulin / metabolism*
  • Insulin Resistance*
  • Insulin Secretion
  • Insulin-Secreting Cells / metabolism*
  • Intra-Abdominal Fat / diagnostic imaging
  • Male
  • Middle Aged
  • Obesity / blood
  • Obesity / diagnostic imaging
  • Obesity / diet therapy
  • Obesity / metabolism
  • Overweight / blood
  • Overweight / diagnostic imaging
  • Overweight / diet therapy*
  • Overweight / metabolism
  • Postprandial Period
  • Weight Loss

Substances

  • Insulin