A process for the modification and regulation of lipid metabolism in a human subject in need of treatment which comprises administering to the subject, over a period ranging from about 30 days to about 120 days, at levels ranging from about 3 micrograms to about 40 micrograms, per pound of body weight, daily doses of a dopamine agonist at from about 1 to about 10 hours after the normal time of day that the prolactin level is at its peak-in a lean insulin-sensitive subject of the same species and sex, to produce a change of the neuroendocrine system of the subject to mimic that of the lean subject such that plasma triglyceride levels are reduced in said subject in need of treatment.