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Updated: Aug 13, 2026
Study of In Vivo Glucose Metabolism in High-fat Diet-fed Mice Using Oral Glucose Tolerance Test (OGTT) and Insulin Tolerance Test (ITT)
Published on: January 7, 2018
Fat oxidation before and after a high fat load in the obese insulin-resistant state
Ellen E Blaak1, Gabby Hul, Camilla Verdich
1Department of Human Biology, Nutrition Research Centre, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands. e.blaak@hb.unimaas.nl
Background:
Obesity may be associated with a lowered use of fat as a fuel, which may contribute to the enlarged adipose tissue stores.
Aim:
The aim of the present study was to study fatty acid use in the fasting state and in response to a high fat load in a large cohort of obese subjects (n = 701) and a lean reference group (n = 113).
Methods:
Subjects from eight European centers underwent a test meal challenge containing 95 en% fat [energy content 50% of estimated resting energy expenditure (EE)]. Fasting and postprandial fat oxidation and circulating metabolites and hormones were determined over a 3-h period.
Results:
Postprandial fat oxidation (as percent of postprandial EE, adjusted for fat mass, age, gender, center, and energy content of the meal) decreased with increasing body mass index (BMI) category (P < 0.01), an effect present only in those obese subjects with a relatively low fasting fat oxidation (below median, interaction BMI category x fasting fat oxidation, P < 0.001). Fasting fat oxidation increased with increasing BMI category (P < 0.001), which was normalized after adjustment for fat-free mass and fat mass. Furthermore, insulin resistance was positively associated with postprandial fat oxidation (P < 0.05) and negatively associated with fasting fat oxidation (expressed as percent of EE), independent of body composition.
Conclusions:
The present data indicate an impaired capacity to regulate fat oxidation in the obese insulin-resistant state, which is hypothesized to play a role in the etiology of both obesity and insulin resistance.
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