The effect of short-term fasting on liver and skeletal muscle lipid, glucose, and energy metabolism in healthy women and men

Jeffrey D. Browning, Jeannie Baxter, Santhosh Satapati, Shawn C. Burgess

Research output: Contribution to journalArticle

37 Scopus citations

Abstract

Fasting promotes triglyceride (TG) accumulation in lean tissues of some animals, but the effect in humans is unknown. Additionally, fasting lipolysis is sexually dimorphic in humans, suggesting that lean tissue TG accumulation and metabolism may differ between women and men. This study investigated lean tissue TG content and metabolism in women and men during extended fasting. Liver and muscle TG content were measured by magnetic resonance spectroscopy during a 48-h fast in healthy men and women. Whole-body and hepatic carbohydrate, lipid, and energy metabolism were also evaluated using biochemical, calorimetric, and stable isotope tracer techniques. As expected, postabsorptive plasma fatty acids (FAs) were higher in women than in men but increased more rapidly in men with the onset of early starvation. Concurrently, sexual dimorphism was apparent in lean tissue TG accumulation during the fast, occurring in livers of men but in muscles of women. Despite differences in lean tissue TG distribution, men and women had identical fasting responses in whole-body and hepatic glucose and oxidative metabolism. In conclusion, TG accumulated in livers of men but in muscles of women during extended fasting. This sexual dimorphism was related to differential fasting plasma FA concentrations but not to whole body or hepatic utilization of this substrate.

Original languageEnglish (US)
Pages (from-to)577-586
Number of pages10
JournalJournal of lipid research
Volume53
Issue number3
DOIs
StatePublished - Mar 1 2012

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Keywords

  • Liver fat
  • Magnetic resonance spectroscopy
  • Muscle fat

ASJC Scopus subject areas

  • Biochemistry
  • Endocrinology
  • Cell Biology

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