Branched fatty acid esters of hydroxy fatty acids (FAHFAs) are lipids recently discovered to be modulated by dietary influences such as fasting and high-fat feeding, and they play a role in enhancing insulin sensitivity. These compounds typically feature a carbon-16 or carbon-18 fatty acid (e.g., palmitoleic, palmitic, oleic, or stearic acid) esterified to a carbon-16 or carbon-18 hydroxy fatty acid. A specific example is 12-SAHSA, which consists of stearic acid linked to 12-hydroxy stearic acid. Notably, 12-SAHSA levels are found to be moderately increased in the serum of glucose tolerant AG4OX mice, a model characterized by adipose tissue-specific overexpression of the Glut4 glucose transporter.