Viscous dietary fibers added to a high fat diet decrease adiposity, improve glucose control and alter fuel utilization in obese rats

Abstract

Viscous dietary fibers reduce the postprandial rise in blood glucose and decrease adiposity in normal and diabetic rats. The purpose of this study was to examine the effects of viscous fibers on fat mass and fuel utilization in a model of diet‐induced obesity. Wistar rats were fed a high fat diet (60% energy from fat) containing 5% fiber as either cellulose (non‐viscous) or one of two highly viscous fibers ‐ hydroxypropyl methylcellulose (HPMC) or guar gum. After 10 weeks of feeding, the HPMC and guar groups had lower fat pad weights and total body fat mass compared to the cellulose group. The guar group had a decreased glucose tolerance test area under the curve (AUC) indicating improved glucose control. AUC during a meal tolerance test was not different with viscous fiber treatment. However, after 3 weeks of feeding, the respiratory quotient (RQ) AUC over 24 hours was increased with HPMC and guar compared to cellulose, implying greater carbohydrate oxidation. The RQ AUC during fasting did not differ between the HPMC and cellulose groups but after a meal it was greater in the HPMC and guar groups. This suggests a quicker transition from fatty acid to carbohydrate oxidation, possibly through decreased insulin resistance. These results indicate that consumption of viscous fibers with a high fat diet can improve glucose control, lower adiposity and increase fuel flexibility.Grant Funding Source: MN Agricultural Experiment Station, MN Obesity Consortium