Plays an important role in the formation of lipid droplets (LDs) which are storage organelles at the center of lipid and energy homeostasis (PubMed:18160536) (By similarity). Directly binds to diacylglycerol (DAGs) and triacylglycerol (By similarity). Primarily expressed in heart and skeletal muscle. Belongs to the FIT family. FIT1 subfamily.