Researchers at Iowa State University took 10 healthy young adults and gave them a mixed meal (14% protein, 22% fat, 64% carb) containing either glutamine or an amino acid mixture (alanine, glycine, serine). Energy expenditure and fat and carbohydrate oxidation rates were assessed for 30 minutes before and 360 minutes after meal ingestion.
Results showed glutamine enhanced fat oxidation by 42 calories compared to mixed amino acids in the late post-meal phase. Researchers concluded glutamine may enhance the action of insulin and promote blood sugar disposal. Long-term use of supplemental glutamine could effect body composition by promoting fat oxidation.