Palmitoleic acid is a common constituent of the triglycerides of human adipose tissue. Palmitoleic acid-based diets raise low-density lipoprotein cholesterol and diminish high-density lipoprotein cholesterol, even when dietary intake of cholesterol is maintained at a low level. Palmitelaidic acid is the trans isomer of the 16:1 fatty acid palmitoleic acid. While its effects on cholesterol levels are poorly studied, palmitelaidic acid can have very different effects from those of palmitoleic acid on lipid metabolism and mobilization. Palmitelaidic acid methyl ester is an ester version of the free acid which may be more amenable for the formulation of fatty acid-containing diets and dietary supplements.