An Increase in Dietary Protein Improves the Blood Glucose Response in Persons With Type 2 Diabetes

Am J Clin Nutr. 2003 Oct;78(4):734-41. doi: 10.1093/ajcn/78.4.734.

Abstract

Background: In single-meal studies, dietary protein does not result in an increase in glucose concentrations in persons with or without type 2 diabetes, even though the resulting amino acids can be used for gluconeogenesis.

Objective: The metabolic effects of a high-protein diet were compared with those of the prototypical healthy (control) diet, which is currently recommended by several scientific organizations.

Design: The metabolic effects of both diets, consumed for 5 wk each (separated by a 2-5-wk washout period), were studied in 12 subjects with untreated type 2 diabetes. The ratio of protein to carbohydrate to fat was 30:40:30 in the high-protein diet and 15:55:30 in the control diet. The subjects remained weight-stable during the study.

Results: With the fasting glucose concentration used as a baseline from which to determine the area under the curve, the high-protein diet resulted in a 40% decrease in the mean 24-h integrated glucose area response. Glycated hemoglobin decreased 0.8% and 0.3% after 5 wk of the high-protein and control diets, respectively; the difference was significant (P < 0.05). The rate of change over time was also significantly greater after the high-protein diet than after the control diet (P < 0.001). Fasting triacylglycerol was significantly lower after the high-protein diet than after the control diet. Insulin, C-peptide, and free fatty acid concentrations were not significantly different after the 2 diets.

Conclusion: A high-protein diet lowers blood glucose postprandially in persons with type 2 diabetes and improves overall glucose control. However, longer-term studies are necessary to determine the total magnitude of response, possible adverse effects, and the long-term acceptability of the diet.

Publication types

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

MeSH terms

  • Adult
  • Aged
  • Blood Glucose / drug effects*
  • Body Weight / drug effects
  • C-Peptide / blood
  • Case-Control Studies
  • Diabetes Mellitus, Type 2 / drug therapy*
  • Dietary Proteins / metabolism
  • Dietary Proteins / therapeutic use*
  • Female
  • Glycated Hemoglobin A / metabolism
  • Humans
  • Insulin / blood
  • Lipids / blood
  • Male
  • Middle Aged
  • Postprandial Period

Substances

  • Blood Glucose
  • C-Peptide
  • Dietary Proteins
  • Glycated Hemoglobin A
  • Insulin
  • Lipids