Short-term low carbohydrate/high-fat diet intake increases postprandial plasma glucose and glucagon-like peptide-1 levels during an oral glucose tolerance test in healthy men.
OBJECTIVE
Postprandial hyperglycemia increases the risks of development of type 2 diabetes and cardiovascular diseases. The purpose of this study was to determine whether a 3-day low-carbohydrate/high-fat diet (LC/HFD) alters postprandial plasma glucose and incretin levels during oral glucose tolerance test (OGTT) in healthy men.


METHODS
Nine healthy young men (age (mean ± s.e.), 27 ± 1 years; body mass index, 22 ± 1 kg/m(2)) consumed either a normal diet (ND: energy from ∼22% fat) or a LC/HFD (energy from ∼69% fat) for 3 days each. The total energy intake from each diet was similar. An OGTT was performed after each 3-day dietary intervention. Postprandial plasma glucose, insulin, free fatty acid and glucagon-like peptide-1 (GLP-1) levels were determined at rest and during the OGTT.


RESULTS
Plasma glucose levels and incremental area under the curve during the OGTT were significantly higher in the LC/HFD trial than in the ND trial (P=0.024). In addition, increase in GLP-1 levels was significantly higher in the LC/HFD trial than in the ND trial (P=0.025). The first-phase insulin secretion indexes were significantly lower in the LC/HFD trial than in the ND trial (P<0.041).


CONCLUSIONS
These results demonstrate that even short-term LC/HFD increased postprandial plasma glucose and GLP-1 levels in healthy young men. A decrease in first-phase insulin secretion may partially contribute to the short-term LC/HFD-induced increase in postprandial plasma glucose levels.
Department of Health and Sports Sciences, Kyoto Pharmaceutical University, Kyoto, Japan. numashige@mb.kyoto-phu.ac.jp
S
S
Numao
H
H
Kawano
N
N
Endo
Y
Y
Yamada
M
M
Konishi
M
M
Takahashi
S
S
Sakamoto
D000328:Adult; D001786:Blood Glucose / Q000032:analysis*; D001823:Body Composition; D015992:Body Mass Index; D059305:Diet, High-Fat / Q000009:adverse effects*; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D002149:Energy Intake; D005230:Fatty Acids, Nonesterified / Q000097:blood; D052216:Glucagon-Like Peptide 1 / Q000097:blood*; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000097:blood / Q000378:metabolism; D000078790:Insulin Secretion; D008297:Male; D009043:Motor Activity; D019518:Postprandial Period / Q000187:drug effects*
D001786:Blood Glucose; D004040:Dietary Carbohydrates; D005230:Fatty Acids, Nonesterified; D007328:Insulin; D052216:Glucagon-Like Peptide 1