Abstract
Control of body fat accumulation by dietetics is very important from a viewpoint of lifestylerelated disease prevention. We studied the effects of molecular species of dietary fat on body fat accumulation. Intake of saturated fatty acids, compared with that of unsaturated fatty acids, decreased diet-induced thermogenesis by a decline of sympathetic activity, reduced Na+, K+-ATPase activity by lowering the level of serum thyroid hormone, and increased the activity of lipoprotein lipase in adipose tissue, thus promoting the accumulation of body fat. In a double-blind, controlled trial in healthy subjects, dietary medium-chain triacylglycerols suppressed the accumulation of body fat. Suitability of medium-chain triacylglycerols for high-temperature cooking was vastly improved by transesterification with long-chain triacylglycerols. Diet-induced thermogenesis was greater for ester-exchange triacylglycerols than for long-chain triacylglycerols in healthy humans. We also demonstrated that ester-exchange triacylglycerols suppressed the accumulation of body fat in healthy subjects. These results suggest not only the quantity but also the quality of fat intake needs to be considered in diet management for obesity prevention.
