Applied nutritional investigationDistinct metabolic pathways trigger adipocyte fat accumulation induced by high-carbohydrate and high-fat diets

ObjectiveSeveral metabolic pathways may be associated with obesity development and may be differentially modulated by dietary constituents. The aim of this study was to access the adipocyte metabolic pathways that lead to lipid accumulation in fat cells of mice fed a high-carbohydrate or high-fat diet.MethodsMale Swiss mice ages 7 to 8 wk were fed a standard laboratory rodent diet-chow diet, a high-carbohydrate (HC) diet, or a high-fat (HF) diet for 8 wk.ResultsAnimals fed the HC diet exhibited a high lipogenesis rate and lipoprotein lipase activity even in a fasted state. Peroxisome proliferator-activated receptor gamma and sterol regulatory element-binding proteins-1 mRNAs were increased in adipose tissue. The HF diet did not promote the lipogenic pathways but attenuated lipolytic activity and glucose uptake in adipocytes.ConclusionThe HC diet induces constitutive expression of lipogenic transcription factors during fasting, whereas the HF diet decreases lipolysis in adipocytes. Both pathways may contribute to increase fat stores and maintain an obese state.