Mice eating a high fat diet for 13 weeks developed insulin resistance and hepatic steatosis.  A study in Food Chemistry shows that piperine in a dose fo 50 mg/kg body weight significantly increased plasma adiponectin levels in mice with high fat diet induced hepatic steatosis.  Piperine also reversed elevated plasma concentrations of insulin and blood sugar and hepatic lipid induced by a high fat diet.  Nevertheless, peiperine did not change body weight and other biomarkers.Piperine is the alkaloid that is responsible for the pungency of black pepper and long pepper.Choi S, Choi Y, Choi Y, Kim S, Jang J, Park T. Piperine reverses high fat diet-induced hepatic steatosis and insulin resistance in mice. Food Chem. 2013 Dec 15;141(4):3627-35. doi: 10.1016/j.foodchem.2013.06.028. Epub 2013 Jun 17.