The present invention relates generally to a method of increasing lipid oxidation in a mammal and to agents useful for same. More particularly, the present invention relates to a method of increasing lipid oxidation in a mammal by administering a ligand which interacts with the IL-6 receptor and signals via interaction with a gp130/LIF receptor heterodimer. In a related aspect, the present invention provides a method of increasing insulin sensitivity in a mammal. The method of present invention is useful, inter alia, in the treatment and/or prophylaxis of conditions characterized by unwanted lipid accumulation (such as obesity, obesity induced-metabolic disorders, type II diabetes, dyslipidemia, glucose intolerance, insulin resistance, obstructive sleep apnea, cardiovascular disease or non-alcoholic fatty liver disease) or inadequate insulin sensitivity.