Three weeks on a high-fat diet increases intrahepatic lipid accumulation and decreases metabolic flexibility in healthy overweight men.

Abstract

CONTEXT:

In rodents, high-fat diets increase intrahepatic lipid (IHL), but human studies are scarce.

OBJECTIVE:

Our objective was to examine whether high-fat diets influence IHL, intramyocellular lipids (IMCL), and insulin resistance.

DESIGN:

Twenty overweight men were randomly allocated to low- or high-fat groups (age, 54.0 ± 2.3 and 56.4 ± 2.5 yr; body mass index, 29.3 ± 0.6 and 28.3 ± 0.5 kg/m(2), respectively). Both groups started with a 3-wk low-fat diet [15% energy (En%) as protein, 65 En% as carbohydrates, 20 En% as fat], after which half of the subjects switched to a 3-wk isocaloric high-fat diet (15 En% protein, 30 En% carbohydrates, 55 En% fat). After 3 and 6 wk, IHL and IMCL content were assessed by (1)H magnetic resonance spectroscopy and a muscle biopsy, and insulin sensitivity was studied using a hyperinsulinemic-euglycemic clamp. An additional liver scan was performed after 1 wk in the high-fat group.

RESULTS:

IHL decreased by 13% in the low-fat group and increased by 17% in high-fat group (P = 0.047). IMCL content was unaffected (P = 0.304). Insulin sensitivity was unaffected. At wk 3, IHL correlated negatively with insulin sensitivity (r = -0.584; P = 0.009, all subjects combined). Metabolic flexibility, defined as change in respiratory quotient upon insulin stimulation, was decreased after 3 wk of the high-fat diet (change in respiratory quotient was +0.02 ± 0.02 vs. -0.05 ± 0.1 in low-fat vs. high-fat group, P = 0.009). Basal plasma glucose increased after the high-fat diet (P = 0.038). Plasma parameters insulin, free fatty acids, high-sensitivity C-reactive protein, and liver enzymes and body weight were unaffected by diet.

CONCLUSION:

A 3-wk high-fat diet leads to IHL accumulation and a decreased metabolic flexibility, but insulin sensitivity is unaffected.

• Authors: Noud A van Herpen, Vera B Schrauwen-Hinderling, Gert Schaart, Ronald P Mensink, Patrick Schrauwen
• Journal: The Journal of clinical endocrinology and metabolism (J Clin Endocrinol Metab) Vol. 96 Issue 4 Pg. E691-5 (Apr 2011) ISSN: 1945-7197 [Electronic] United States
• PMID: 21252252 (Publication Type: Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)

Chemical References

• Dietary Fats

Topics

• Diet, Atherogenic
• Diet, Fat-Restricted
• Dietary Fats (pharmacology)
• Eating (physiology)
• Health
• Humans
• Insulin Resistance (physiology)
• Lipid Metabolism (drug effects)
• Liver (metabolism)
• Male
• Metabolism (drug effects)
• Middle Aged
• Muscle, Skeletal (drug effects, metabolism)
• Overweight (metabolism)
• Time Factors