An increase in dietary protein improves the blood glucose response in persons with type 2 diabetes.
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.


METHODS
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.


CONCLUSIONS
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.
Gannon
Mary C
MC
Metabolic Research Laboratory and the Section of Endocrinology, Metabolism, and Nutrition, Department of Veterans Affairs Medical Center, Minneapolis, Minnesota 55417, USA. ganno004@tc.umn.edu
Nuttall
Frank Q
FQ
Saeed
Asad
A
Jordan
Kelly
K
Hoover
Heidi
H
D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000187:drug effects*; D001835:Body Weight / Q000187:drug effects; D002096:C-Peptide / Q000097:blood; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy*; D004044:Dietary Proteins / Q000378:metabolism / Q000627:therapeutic use*; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000097:blood; D008055:Lipids / Q000097:blood; D008297:Male; D008875:Middle Aged; D019518:Postprandial Period
D001786:Blood Glucose; D002096:C-Peptide; D004044:Dietary Proteins; D006442:Glycated Hemoglobin; D007328:Insulin; D008055:Lipids