Dietary fat content alters insulin-mediated glucose metabolism in healthy men.
BACKGROUND
A high dietary fat intake is involved in the pathogenesis of insulin resistance.


OBJECTIVE
The aim was to compare the effect of different amounts of dietary fat on hepatic and peripheral insulin sensitivity.


METHODS
Six healthy men were studied on 3 occasions after consuming for 11 d diets with identical energy and protein contents but different percentages of energy as fat and carbohydrate as follows: 0% and 85% [low-fat, high-carbohydrate (LFHC) diet], 41% and 44% [intermediate-fat, intermediate-carbohydrate (IFIC) diet], and 83% and 2% [high-fat, low-carbohydrate (HFLC) diet]. Insulin sensitivity was quantified by using a hyperinsulinemic euglycemic clamp (plasma insulin concentration: approximately 190 pmol/L).


RESULTS
During hyperinsulinemia, endogenous glucose production was higher after the HFLC diet (2.5 +/- 0.3 micromol x kg(-1) x min(-1); P < 0.05) than after the IFIC and LFHC diets (1.7 +/- 0.3 and 1.2 +/- 0.4 micromol x kg(-1) x min(-1), respectively). The ratio of dietary fat to carbohydrate had no unequivocal effects on insulin-stimulated glucose uptake. In contrast, insulin-stimulated, nonoxidative glucose disposal tended to increase in relation to an increase in the ratio of fat to carbohydrate, from 14.8 +/- 5.1 to 20.6 +/- 1.9 to 26.2 +/- 2.9 micromol x kg(-1) x min(-1) (P < 0.074 between the 3 diets). Insulin-stimulated glucose oxidation was significantly lower after the HFLC diet than after the IFIC and LFHC diets: 1.7 +/- 0.8 compared with 13.4 +/- 2.1 and 19.0 +/- 2.1 micromol x kg(-1) x min(-1), respectively (P < 0.05). During the clamp study, plasma fatty acid concentrations were higher after the HFLC diet than after the IFIC and LFHC diets: 0.22 +/- 0.02 compared with 0.07 +/- 0.01 and 0.05 +/- 0.01 mmol/L, respectively (P < 0.05).


CONCLUSIONS
A high-fat, low-carbohydrate intake reduces the ability of insulin to suppress endogenous glucose production and alters the relation between oxidative and nonoxidative glucose disposal in a way that favors storage of glucose.
Bisschop
P H
PH
Departments of Endocrinology and Metabolism, Clinical Chemistry Laboratory of Endocrinology, and Biochemistry, Academic Medical Center, University of Amsterdam, The Netherlands. p.h.bisschop@amc.uva.nl
de Metz
J
J
Ackermans
M T
MT
Endert
E
E
Pijl
H
H
Kuipers
F
F
Meijer
A J
AJ
Sauerwein
H P
HP
Romijn
J A
JA
D000328:Adult; D001786:Blood Glucose / Q000378:metabolism*; D002153:Calorimetry, Indirect; D004040:Dietary Carbohydrates / Q000008:administration & dosage / Q000494:pharmacology; D004041:Dietary Fats / Q000008:administration & dosage / Q000494:pharmacology*; D004734:Energy Metabolism; D005227:Fatty Acids / Q000097:blood; D008401:Gas Chromatography-Mass Spectrometry; D015309:Glucose Clamp Technique; D006801:Humans; D007328:Insulin / Q000097:blood* / Q000378:metabolism; D007333:Insulin Resistance; D007700:Kinetics; D008099:Liver / Q000378:metabolism*; D008297:Male; D008875:Middle Aged
D001786:Blood Glucose; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D005227:Fatty Acids; D007328:Insulin