Partial restoration of dietary fat induced metabolic adaptations to training by 7 days of carbohydrate diet.

Full Abstract

We tested the hypothesis that a shift to carbohydrate diet after prolonged adaptation to fat diet would lead to decreased glucose uptake and impaired muscle glycogen breakdown during exercise compared with ingestion of a carbohydrate diet all along. We studied 13 untrained men; 7 consumed a high-fat (Fat-CHO; 62% fat, 21% carbohydrate) and 6 a high-carbohydrate diet (CHO; 20% fat, 65% carbohydrate) for 7 wk, and thereafter both groups consumed the carbohydrate diet for an eighth week. Training was performed throughout. After 8 wk, during 60 min of exercise (71 +/- 1% pretraining maximal oxygen uptake) average leg glucose uptake (1.00 +/- 0.07 vs. 1.55 +/- 0.21 mmol/min) was lower (P < 0.05) in Fat-CHO than in CHO. The rate of muscle glycogen breakdown was similar (4.4 +/- 0.5 vs. 4.2 +/- 0.7 mmol. min(-1). kg dry wt(-1)) despite a significantly higher preexercise glycogen concentration (872 +/- 59 vs. 688 +/- 43 mmol/kg dry wt) in Fat-CHO than in CHO. In conclusion, shift to carbohydrate diet after prolonged adaptation to fat diet and training causes increased resting muscle glycogen levels but impaired leg glucose uptake and similar muscle glycogen breakdown, despite higher resting levels, compared with when the carbohydrate diet is consumed throughout training.

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Author information

Author/s: Helge, Jørn W (JW); Watt, Peter W (PW); Richter, Erik A (EA); Rennie, Michael J (MJ); Kiens, Bente (B);

Affiliation: Copenhagen Muscle Research Centre, Department of Human Physiology, University of Copenhagen, DK-2100 Copenhagen Ø, Denmark. jhelge(-atsign-)mgi.ku.dk

Journal and publication information

Publication Type: Journal Article; Research Support, Non-U.S. Gov't

Journal: Journal of applied physiology (Bethesda, Md. : 1985) (J Appl Physiol), published in United States. (Language: eng)

Reference: 2002-Nov; vol 93 (issue 5) : pp 1797-805

Dates: Created 2002/10/16; Completed 2003/04/10; Revised 2006/11/15;

PMID: 12381768, status: MEDLINE (last retrieval date: 12/26/2008)

Sourced from the National Library of Medicine. Abstract text and other information may be subject to copyright.

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MeSH headings (categories)

This article was linked to the MESH Headings shown below.

Adaptation, Physiological - physiology
Adult
Dietary Carbohydrates - administration & dosage
Dietary Fats - administration & dosage
Dose-Response Relationship, Drug
Glucose - metabolism
Glycogen - metabolism
Humans

Humans
Leg - blood supply
Male
Muscle, Skeletal - drug effects; metabolism
Osmolar Concentration
Physical Education and Training
Regional Blood Flow
Rest - physiology

Associated Chemicals: Dietary Carbohydrates (0) ; Dietary Fats (0) ; Glucose (50-99-7) ; Glycogen (9005-79-2)

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