The differentiation of preadipocytic cells into adipocytic cells, in particular for correcting insulin-resistance disease states in mammalian organisms, notably in humans, for example type II diabetes and cardiovascular disorders such as hypertension and atherosclerosis, is stimulated by treating such preadipocytic cells, or a patient in need of such treatment, with an effective amount of (a) at least one ligand displaying affinity for the nuclear receptors for retinoic acid and/or isomers thereof, preferably at least one ligand displaying a specific affinity for the RAR receptors and even more preferably the RAR-&agr; receptor and (b) at least one fatty acid, e.g., a polyunsaturated fatty acid.