title: Diurnal trends in responses of blood plasma concentrations of glucose, insulin, and C-peptide following high- and low-fat meals and their relation to fat metabolism in healthy middle-aged volunteers.
abstract: An experiment was conducted in twelve healthy middle-aged volunteers, six of each sex, with a mean BMI of 27 kg/m2 to detect differences between morning and afternoon in postprandial blood glucose, insulin and C-peptide concentrations. These responses were measured following the consumption of isoenergetic meals that were high or low in fat content, at breakfast and at lunch. Over 4 d each subject received the high-carbohydrate (L, 5.5 g mixed fat/meal) and moderately high-fat (M, 33 g mixed fat/meal) breakfasts and lunches, in three combinations (LL, MM, LM), or they fasted at breakfast time and received a moderately high-fat lunch (NM), in three Latin squares. Each evening a standard meal was given. Plasma glucose, insulin and C-peptide responses were greater following L than M meals and within both MM and LL treatments insulin and C-peptide responses were greater following breakfast than following lunch. The incremental C-peptide response to a fatty lunch following a fast at breakfast time (NM) was similar to that to a fatty breakfast, but the incremental insulin response for the same comparison was marginally lower at lunch (P = 0.06). The relationship of C-peptide and insulin concentrations was assessed. Plasma glucose response to a fatty lunch was increased by a fatty breakfast. The relationships of these metabolic events with fat metabolism are discussed.
authors.affiliation: N.S. Research, Suffolk.
authors.forename: D L
authors.initials: DL
authors.lastname: Frape
authors.forename: N R
authors.initials: NR
authors.lastname: Williams
authors.forename: A J
authors.initials: AJ
authors.lastname: Scriven
authors.forename: C R
authors.initials: CR
authors.lastname: Palmer
authors.forename: K
authors.initials: K
authors.lastname: O'Sullivan
authors.forename: R J
authors.initials: RJ
authors.lastname: Fletcher
mesh_terms: D001786:Blood Glucose / Q000378:metabolism*; D002096:C-Peptide / Q000097:blood; D002784:Cholesterol / Q000097:blood; D002940:Circadian Rhythm; D004040:Dietary Carbohydrates / Q000008:administration & dosage; D004041:Dietary Fats / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood*; D008297:Male; D008875:Middle Aged; D019518:Postprandial Period; D014280:Triglycerides / Q000097:blood
chemical_list: D001786:Blood Glucose; D002096:C-Peptide; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D007328:Insulin; D014280:Triglycerides; D002784:Cholesterol