Original Article

International Journal of Obesity (2008) 32, 481–489; doi:10.1038/sj.ijo.0803754; published online 13 November 2007

Energy replacement attenuates the effects of prior moderate exercise on postprandial metabolism in overweight/obese men

F L Burton1, D Malkova1, M J Caslake2 and J M R Gill1

  1. 1Institute of Diet, Exercise and Lifestyle, Institute of Biomedical and Life Sciences, University of Glasgow, Glasgow, UK
  2. 2Section of Vascular Biochemistry, University of Glasgow, Glasgow, UK

Correspondence: Dr JMR Gill, Institute of Diet, Exercise and Lifestyle, Institute of Biomedical and Life Sciences, University of Glasgow, University Avenue, West Medical Building, Glasgow G12 8QQ, UK. E-mail: j.gill@bio.gla.ac.uk

Received 10 June 2007; Revised 18 September 2007; Accepted 18 September 2007; Published online 13 November 2007.

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Abstract

Background:

 

The extent to which exercise-induced changes to postprandial metabolism are dependant on the associated energy deficit is not known.

Objective:

 

To determine the effects of exercise, with and without energy replacement, on postprandial metabolism.

Design:

 

Each subject underwent three 2-day trials in random order. On day 1 of each trial subjects rested (control), walked at 50% maximal oxygen uptake to induce a net energy expenditure of 27 kJ kg-1 body mass (energy-deficit) or completed the same walk with the net energy expended replaced (energy-replacement). On day 2 subjects completed an 8.5-h metabolic assessment. For 3 days prior to day 2, subjects consumed an isocaloric diet, avoided planned exercise (apart from exercise interventions) and alcohol.

Subjects:

 

A total of 13 overweight/obese men (age: 40plusminus8 years, body mass index: 31.1plusminus3.0 kg m-2).

Measurements:

 

Postprandial triglyceride, insulin, glucose, non-esterified fatty acid and 3-hydroxybutyrate concentrations and substrate utilization rates were determined.

Results:

 

Energy-deficit lowered postprandial triglyceride concentrations by 14 and 10% compared with control and energy-replacement (P<0.05 for both). Energy-deficit increased postprandial 3-hydroxybutyrate concentrations by 40 and 19% compared with control and energy-replacement (P<0.05 for both). Postprandial insulin concentrations were 18 and 10% lower for energy-deficit and energy-replacement compared with control and 10% lower for energy-deficit than energy-replacement (P<0.05 for all). Postprandial fat oxidation increased by 30 and 14% for energy-deficit and energy-replacement compared to control and was 12% higher for energy-deficit than energy-replacement (P<0.05 for all).

Conclusion:

 

Exercise with energy replacement lowered postprandial insulinaemia and increased fat oxidation. However an exercise-induced energy deficit augmented these effects and was necessary to lower postprandial lipaemia.

Keywords:

exercise, energy deficit, postprandial, triglyceride, insulin, fat oxidation

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