Epidemilogical studies have shown that whole grains consumption prevents obesity and type 2 diabetes. Brown rice induces less postprandial blood glucose increase compared with white rice. Recently, brown rice consumption has been proved to exhibit anti-obese effect in humans. Whereas several components in rice bran have been shown to have beneficial function for prevention of obesity and type 2 diabetes, active components in brown rice have not been fully clarified. Our recent studies have demonstrated that dietary consumption of triterpene alcohol and sterol preparation (TASP) from rice bran prevented high-fat diet-induced obesity and reduced postprandial blood glucose increase in mice. Moreover, TASP consumption significantly reduced postprandial hyperglycemia in humans. Reduction in postprandial glucose-dependent insulinotropic peptide increase in blood and inhibition of sodium-dependent glucose transporter 1 translocation to the plasma membrane are likely to underlie the beneficial function of TASP. Brown rice-derived TASP can be industrially produced from rice bran that is being discarded on a massive scale. Application of TASP to functional food development can be expected to be quite useful for prevention and improvement of obesity and type 2 diabetes. Present paper would review our recent findings of physiological function of rice bran-derived TASP and its underlying mechanisms.