Dietary Methionine Restriction Increases Fat Oxidation in Obese Adults with Metabolic Syndrome

Pennington Biomedical Research Center, Baton Rouge, Louisiana 70808, USA.
The Journal of Clinical Endocrinology and Metabolism (Impact Factor: 6.21). 02/2011; 96(5):E836-40. DOI: 10.1210/jc.2010-2493
Source: PubMed


In preclinical reports, restriction of dietary methionine intake was shown to enhance metabolic flexibility, improve lipid profiles, and reduce fat deposition. The present report is the outcome of a "proof of concept" study to evaluate the efficacy of dietary methionine restriction (MR) in humans with metabolic syndrome.
Twenty-six obese subjects (six male and 20 female) meeting criteria for metabolic syndrome were randomized to a diet restricted to 2 mg methionine/kg body weight per day and were provided capsules containing either placebo (n = 12) or 33 mg methionine/kg body weight per day (n = 14). Energy expenditure, body composition, insulin sensitivity, and biomarkers of metabolic syndrome were measured before and after 16 wk on the respective diets.
Insulin sensitivity and biomarkers of metabolic syndrome improved comparably in both dietary groups. Rates of energy expenditure were unaffected by the diets, but dietary MR produced a significant increase in fat oxidation (MR, 12.1 ± 6.0% increase; control, 8.1 ± 3.3% decrease) and reduction in intrahepatic lipid content (MR liver/spleen attenuation ratio, 8.1 ± 3.3% increase; control ratio, 2.2 ± 2.1% increase) that was independent of the comparable reduction in weight and adiposity that occurred in both groups.
Sixteen weeks of dietary MR in subjects with metabolic syndrome produced a shift in fuel oxidation that was independent of the weight loss, decreased adiposity, and improved insulin sensitivity that was common to both diets.

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    • "Additional studies will be required to systematically measure the in vivo rates of these components to identify the specific difference in the way juvenile and adult rats respond to MR. However, we note that in adult subjects with metabolic syndrome, dietary MR for 16 weeks increased overall fatty acid oxidation and reduced hepatic lipid levels (20). "
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