Obesity, high fat diet, and urine metabolites

To investigate metabolic changes in the urine of a rat model of obesity induced by a high-fat diet (HFD), rats were divided into the following four groups based on the diet type and degree of weight gain: normal-diet (ND) low gainers, ND high gainers, HFD low gainers, and HFD high gainers. Biochemical analyses of visceral fat-pad weight, plasma, and liver tissues were performed.

It was observed that the metabolic profile of urine obtained by 1H-NMR-spectroscopy-based metabolomic analysis differed between ND low gainers and ND high gainers even though these animals consumed the same normal diet. Several key metabolites in urine, such as betaine, taurine, acetone/acetoacetate, phenylacetylglycine, pyruvate, lactate, and citrate contributed to the classification of these two groups. The metabolic profile of urine also differed between ND low gainers and HFD high gainers, which consumed the different diet and showed a different weight gain.

In short, these key metabolites, including betaine, were at higher concentrations in urine for high gainers vs low gainers.

This study has identified features of urine metabolites in various groups and demonstrated the reliability of an NMR-based metabolomics approach to investigate the effects of the diet and the physical constitution on obesity.

Kim et al (2009). "(1)H-nuclear magnetic resonance spectroscopy-based metabolic assessment in a rat model of obesity induced by a high-fat diet." Anal Bioanal Chem. Epub August