A high-protein breakfast induces greater insulin and glucose-dependent insulinotropic peptide responses to a subsequent lunch meal in individuals with type 2 diabetes.
BACKGROUND
The previous meal modulates the postprandial glycemic responses to a subsequent meal; this is termed the second-meal phenomenon.


OBJECTIVE
This study examined the effects of high-protein vs. high-carbohydrate breakfast meals on the metabolic and incretin responses after the breakfast and lunch meals.


METHODS
Twelve type 2 diabetic men and women [age: 21-55 y; body mass index (BMI): 30-40 kg/m(2)] completed two 7-d breakfast conditions consisting of 500-kcal breakfast meals as protein (35% protein/45% carbohydrate) or carbohydrate (15% protein/65% carbohydrate). On day 7, subjects completed an 8-h testing day. After an overnight fast, the subjects consumed their respective breakfast followed by a standard 500-kcal high-carbohydrate lunch meal 4 h later. Blood samples were taken throughout the day for assessment of 4-h postbreakfast and 4-h postlunch total area under the curve (AUC) for glucose, insulin, C-peptide, glucagon, glucose-dependent insulinotropic peptide (GIP), and glucagon-like peptide 1 (GLP-1).


RESULTS
Postbreakfast glucose and GIP AUCs were lower after the protein (17%) vs. after the carbohydrate (23%) condition (P < 0.05), whereas postbreakfast insulin, C-peptide, glucagon, and GLP-1 AUCs were not different between conditions. A protein-rich breakfast may reduce the consequences of hyperglycemia in this population. Postlunch insulin, C-peptide, and GIP AUCs were greater after the protein condition vs. after the carbohydrate condition (second-meal phenomenon; all, P < 0.05), but postlunch AUCs were not different between conditions. The overall glucose, glucagon, and GLP-1 responses (e.g., 8 h) were greater after the protein condition vs. after the carbohydrate condition (all, P < 0.05).


CONCLUSIONS
In type 2 diabetic individuals, compared with a high-carbohydrate breakfast, the consumption of a high-protein breakfast meal attenuates the postprandial glucose response and does not magnify the response to the second meal. Insulin, C-peptide, and GIP concentrations demonstrate the second-meal phenomenon and most likely aid in keeping the glucose concentrations controlled in response to the subsequent meal. The trial was registered at www.clinicaltrials.gov/ct2/show/NCT02180646 as NCT02180646.
Departments of Nutrition and Exercise Physiology and.
Young-Min
YM
Park
Departments of Nutrition and Exercise Physiology and.
Timothy D
TD
Heden
Departments of Nutrition and Exercise Physiology and.
Ying
Y
Liu
Departments of Nutrition and Exercise Physiology and.
Lauryn M
LM
Nyhoff
Departments of Nutrition and Exercise Physiology and Medicine, Division of Gastroenterology and Hepatology, University of Missouri, Columbia, MO.
John P
JP
Thyfault
Departments of Nutrition and Exercise Physiology and.
Heather J
HJ
Leidy
Departments of Nutrition and Exercise Physiology and kanaleyj@missouri.edu.
Jill A
JA
Kanaley
D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D062408:Breakfast; D002096:C-Peptide / Q000097:blood; D018592:Cross-Over Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000178:diet therapy*; D004032:Diet; D015930:Diet Records; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D004044:Dietary Proteins / Q000008:administration & dosage*; D002149:Energy Intake; D005260:Female; D005749:Gastric Inhibitory Polypeptide / Q000097:blood*; D005934:Glucagon / Q000097:blood; D052216:Glucagon-Like Peptide 1 / Q000097:blood; D006801:Humans; D006943:Hyperglycemia / Q000097:blood / Q000178:diet therapy; D007328:Insulin / Q000097:blood*; D062409:Lunch; D008297:Male; D008875:Middle Aged; D019518:Postprandial Period / Q000187:drug effects; D016037:Single-Blind Method; D055815:Young Adult
D001786:Blood Glucose; D002096:C-Peptide; D004040:Dietary Carbohydrates; D004044:Dietary Proteins; D007328:Insulin; D005749:Gastric Inhibitory Polypeptide; D052216:Glucagon-Like Peptide 1; D005934:Glucagon
GIP; GLP-1; glucagon; high carbohydrate; postprandial glucose; second-meal phenomenon; type 2 diabetes