Protein co-ingestion strongly increases postprandial insulin secretion in type 2 diabetes patients

J Med Food. 2014 Jul;17(7):758-63. doi: 10.1089/jmf.2012.0294. Epub 2014 Mar 10.


The capacity of nutritional protein to induce endogenous insulin secretion has been well established. However, it is not known whether such a response is applicable in a diverse population of type 2 diabetes patients. The aim of the present study was to assess the impact of co-ingesting either intact or hydrolyzed protein with carbohydrate on postprandial plasma insulin and glucose responses in type 2 diabetes patients. Sixty longstanding, male, type 2 diabetes patients participated in a study in which we determined postprandial plasma insulin and glucose responses after ingesting a single bolus of carbohydrate (0.7 g/kg: CHO) with or without an intact protein (0.3 g/kg: PRO) or its hydrolysate (0.3 g/kg: PROh). Results showed that protein co-ingestion strongly increased postprandial insulin release, with the insulin response +99 ± 41 and +110 ± 10% greater in the CHO+PRO and CHO+PROh experiments when compared with the CHO experiment. The insulinotropic properties of protein co-ingestion were evident in nearly all patients, with 58 out of 60 patients responding >10% when compared with the insulin response following carbohydrate ingestion only (CHO). The concomitant plasma glucose responses were 22 ± 32 and 23 ± 36% lower in the CHO+PRO and CHO+PROh experiments, respectively. We conclude that protein co-ingestion represents an effective dietary strategy to strongly augment postprandial insulin release and attenuate the postprandial rise in glucose concentration in type 2 diabetes patients.

Keywords: glucose; insulin; milk protein; protein hydrolysates.

Publication types

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

MeSH terms

  • Adult
  • Aged
  • Blood Glucose / metabolism
  • Cross-Over Studies
  • Diabetes Mellitus, Type 2 / blood*
  • Dietary Carbohydrates / administration & dosage*
  • Dietary Proteins / administration & dosage*
  • Double-Blind Method
  • Humans
  • Insulin / blood
  • Insulin / metabolism*
  • Insulin Secretion
  • Male
  • Middle Aged
  • Postprandial Period*
  • Protein Hydrolysates / administration & dosage


  • Blood Glucose
  • Dietary Carbohydrates
  • Dietary Proteins
  • Insulin
  • Protein Hydrolysates