Dietary Lipids Are Largely Deposited in Skin and Rapidly Affect Insulating Properties

This study demonstrates that the skin plays a significant role in energy expenditure and metabolism, particularly in response to dietary lipids. In mice, a high-fat diet quickly reduces heat transfer through the skin, while a diet preventing obesity increases energy loss. The skin is identified as the primary site for dietary fat deposition, with triglycerides being absorbed by the epidermis and dermal white adipose tissue, remaining for weeks. Caloric restriction leads to thinner skin and reduced lipid assimilation. The study highlights the importance of including skin in physiological studies of lipid metabolism due to its large lipid reservoir and adaptable thermal properties.