Abstract
Objectives
The objective of this study was to investigate the main and interactive effects of fat and sodium content of the diet on food intake, body weight and composition, glucose metabolism and blood pressure in male Wistar rats.
Methods
Male Wistar Rats (n = 48, initial body weight: 115.30 ± 1.73 g) were allocated into 4 groups (n = 12/group) and received one of the following diets: Normal sodium normal fat (NSNF), normal sodium high fat (NSHF), high sodium normal fat (HSNF), high sodium high fat (HSHF) diet for 12 weeks. Body weight (BW) and food intake (FI) were measured weekly. Short-term food intake (1, 2 and 12 hours food intake after 12 hours fasting) was measured at week 6. Body composition and organs’ weight were measured at week 12. Systolic (SBP) and diastolic (DBP) blood pressure, pulse and fasting blood glucose (FBG) were measured and oral glucose tolerance test (OGTT) was conducted at weeks 1, 4, 8 and 12.
Results
Regardless of sodium content, a greater FI (both gram and cal) was observed in rats fed normal fat diet compared with those fed high fat diet. Consistently, FI (g) at 1, 2 and 12 hours was higher in rats fed a normal fat diet. However, no difference in calorie intake was observed at any time point. Higher BW and fat (%) was observed in high fat diet groups. Moreover, greater kidneys’ weights was observed in high sodium diet groups. Fasting blood glucose was higher in rats fed a normal sodium diet compared with those fed a high sodium diet while the tAUC glucose response to glucose preload was higher in rats fed a high fat diet compared with those fed a normal fat diet which is consistent with higher body weight in high fat diet groups. Regardless of fat content of the diet, pulse was higher in rats fed a high sodium diet compared with those fed a normal sodium diet. No effect of either dietary sodium or fat content of the diet on SBP or DBP was observed.
Conclusions
Fat but not sodium content of the diet is a determining factor in regulation of FI and BW. Moreover, both fat and sodium content of the diet influence the glucose metabolism potentially through different mechanisms. While pulse is influenced by sodium content, the results of this study do not support the effect of sodium or fat content of the diet on either SBP or DBP.
Funding Sources
UNF, Brooks College of Health internal grant.