Effects of different amounts and types of dietary fatty acids on the body weight, fat accumulation, and lipid metabolism in hamsters

Objectives: The aim of this study was to explore the effects of different amounts of dietary fatty acids on body weight, fat accumulation, and lipid metabolism of hamsters. Methods: Sixty male golden Syrian hamsters were randomly divided into six groups. Three of the groups (the S groups) were fed experimental diets containing 5%, 15%, and 20% (w/w) fat of soybean oil (S₅, S₁₅, and S₂₀, respectively), and the other three groups (the M groups) were fed the same proportions of an experimental oil mixture (M₅, M₁₅, and M₂₀, respectively). The experimental oil mixture consisted of 60% monounsaturated fatty acids (MUFAs) and a polyunsaturated-to-saturated fatty acid ratio of 5 with a mixture of soybean and canola oils. Food consumption was measured daily, and body weights were measured weekly. Serum insulin and leptin concentrations were measured and hepatic fatty acid metabolic enzymes and adipose differentiation markers were determined using an enzyme activity analysis and quantitative polymerase chain reaction. Results: Results showed that the weight and weight gain of the S₂₀ group were significantly greater than those of the other five groups. When the total fat consumption increased, the body weight, weight gain, and adipose tissue weight of the S groups significantly increased, but there were no significant differences in these parameters among the M groups. Serum low-density lipoprotein cholesterol concentrations were significantly lower in the M₁₅ and S₁₅ groups. The S₂₀ group had significantly higher leptin and insulin concentrations and lipoprotein lipase was promoted, but the acetyl-coenzyme A oxidase and carnitine palmitoyltransferase-1, were significantly lower. Conclusions: The study demonstrated that a special experimental oil mixture (with 60% MUFAs and a ratio of 5) with high fat can prevent body weight gain and body fat accumulation by lowering insulin concentrations and increasing hepatic lipolytic enzyme activities.