A High Protein Diet Is More Effective in Improving Insulin Resistance and Glycemic Variability Compared to a Mediterranean Diet-A Cross-Over Controlled Inpatient Dietary Study

Nutrients. 2021 Dec 7;13(12):4380. doi: 10.3390/nu13124380.

Abstract

The optimal dietary pattern to improve metabolic function remains elusive. In a 21-day randomized controlled inpatient crossover feeding trial of 20 insulin-resistant obese women, we assessed the extent to which two isocaloric dietary interventions-Mediterranean (M) and high protein (HP)-improved metabolic parameters. Obese women were assigned to one of the following dietary sequences: M-HP or HP-M. Cardiometabolic parameters, body weight, glucose monitoring and gut microbiome composition were assessed. Sixteen women completed the study. Compared to the M diet, the HP diet was more effective in (i) reducing insulin resistance (insulin: Beta (95% CI) = -6.98 (-12.30, -1.65) µIU/mL, p = 0.01; HOMA-IR: -1.78 (95% CI: -3.03, -0.52), p = 9 × 10-3); and (ii) improving glycemic variability (-3.13 (-4.60, -1.67) mg/dL, p = 4 × 10-4), a risk factor for T2D development. We then identified a panel of 10 microbial genera predictive of the difference in glycemic variability between the two diets. These include the genera Coprococcus and Lachnoclostridium, previously associated with glucose homeostasis and insulin resistance. Our results suggest that morbidly obese women with insulin resistance can achieve better control of insulin resistance and glycemic variability on a high HP diet compared to an M diet.

Keywords: Mediterranean diet; dietary intervention; glycemic variability; gut microbiome; high protein diet; insulin resistance; obesity.

Publication types

  • Comparative Study
  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Cross-Over Studies
  • Diet, High-Protein*
  • Diet, Mediterranean*
  • Female
  • Gastrointestinal Microbiome
  • Glycemic Index*
  • Homeostasis
  • Humans
  • Insulin Resistance*
  • Middle Aged
  • Obesity / diet therapy*
  • Obesity / metabolism*
  • Obesity / microbiology
  • Treatment Outcome
  • Young Adult