Sequential effects of a high-fat, calorie-dense diet or a high-fiber diet on gene expression, body weight and associated metabolic responses in C57/BL6J Mice

Abstract

This thesis sequentially examined the feeding behaviour in female C57BL/6J mice and the transcriptomic profile of genes involved in lipid metabolism over a period of 10 weeks in response to consuming a high-fat, calorie-dense (HFC) diet. In parallel, plasma lipid, leptin and insulin levels were measured. The results suggested that the early responses to HFC feeding were possibly aimed at reducing food intake, down-regulating lipogenic hepatic genes and up-regulating genes involved in fatty acid oxidation. However, prolonged HFC feeding appeared to disrupt this adaptation, leading to marked increases in food intake and body fat. The thesis proposed a possible model linking leptin signalling, hepatic lipid metabolism and the control of food intake. In a separate experiment, the thesis also examined the effects of a high-fiber diet on the genes involved in lipid metabolism. Both experiments provided important molecular insights into the genes involved in regulating lipid and energy stores.