title: Alteration of postprandial glucose and insulin concentrations with meal frequency and composition.
abstract: A frequent eating pattern may alter glycaemic control and augment postprandial insulin concentrations in some individuals due to the truncation of the previous postprandial period by a subsequent meal. The present study examined glucose, insulin, C-peptide and glucose-dependent insulinotropic peptide (GIP) responses in obese individuals when meals were ingested in a high-frequency pattern (every 2 h, 6M) or in a low-frequency pattern (every 4 h, 3M) over 12 h. It also examined these postprandial responses to high-frequency, high-protein meals (6MHP). In total, thirteen obese subjects completed three 12 h study days during which they consumed 6276 kJ (1500 kcal): (1) 3M - 15 % protein and 65 % carbohydrate; (2) 6M - 15 % protein and 65 % carbohydrate; (3) 6MHP - 45 % protein and 35 % carbohydrate. Blood samples were collected every 10 min and analysed for glucose, insulin, C-peptide and GIP. Insulin total AUC (tAUC) and peak insulin concentrations (P< 0·05) were higher in the 3M condition than in the 6M condition, but there were no differences in glucose tAUC between the conditions. The 6MHP regimen (glucose: 3569 (se 83) mmol/l × min (64·3 (se 1·5) g/dl × min), insulin: 1·577 (se 0·146) pmol/l (22·7 (se 2·1) μIU/dl) for 12 h) lowered glucose and insulin excursions more so over 12 h than either the 3M regimen (glucose: 3913 (se 78) mmol/l × min (70·5 (se 1·4) g/dl × min), insulin: 2·195 (se 0·146) pmol/l × min (31·6 (se 2·1) μIU/dl × min) for 12 h) or the 6M regimen (glucose: 3902 (se 83) mmol/l × min (70·3 (se 1·5) g/dl × min), insulin: 1·861 (se 0·174) pmol/l × min (26·8 (se 2·5) μIU/dl × min) for 12 h; P< 0·01). Insulin secretion, GIP concentrations and the glucose:insulin ratio were not altered by meal frequency or composition. In obese subjects, ingestion of meals in a low-frequency pattern does not alter glucose tAUC, but increases postprandial insulin responses. The substitution of carbohydrates with protein in a frequent meal pattern results in tighter glycaemic control and reduced postprandial insulin responses.
authors.affiliation: Department of Nutrition and Exercise Physiology,University of Missouri,217 Gwynn Hall,Columbia,MO65211,USA.
authors.forename: Jill A
authors.initials: JA
authors.lastname: Kanaley
authors.affiliation: Department of Nutrition and Exercise Physiology,University of Missouri,217 Gwynn Hall,Columbia,MO65211,USA.
authors.forename: Timothy D
authors.initials: TD
authors.lastname: Heden
authors.affiliation: Department of Nutrition and Exercise Physiology,University of Missouri,217 Gwynn Hall,Columbia,MO65211,USA.
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.affiliation: School of Psychology and Exercise Science, Murdoch University,Murdoch,Western Australia,Australia.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Fairchild
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000032:analysis*; D002096:C-Peptide / Q000097:blood; D004040:Dietary Carbohydrates / Q000008:administration & dosage; D004044:Dietary Proteins / Q000008:administration & dosage; D002149:Energy Intake; D005215:Fasting / Q000097:blood*; D005260:Female; D005749:Gastric Inhibitory Polypeptide / Q000097:blood; D006801:Humans; D007328:Insulin / Q000097:blood*; D007700:Kinetics; D008297:Male; D062407:Meals; D008875:Middle Aged; D009765:Obesity / Q000097:blood*; D019518:Postprandial Period / Q000502:physiology*; D013997:Time Factors
chemical_list: D001786:Blood Glucose; D002096:C-Peptide; D004040:Dietary Carbohydrates; D004044:Dietary Proteins; D007328:Insulin; D005749:Gastric Inhibitory Polypeptide