determined using quantitative RT-PCR relative to that of the housekeeper beta-2 microglobulin. Results: Relative duodenal expression of GPR40 and CD36 was increased, while GPR119 and 120 was decreased in overweight compared to lean subjects, however these changes were not significant; FA receptor expression was unaltered by acute lipid exposure in either group. Changes in expression of GRP40 and GPR119 during lipid infusion, in contrast, were significantly and positively correlated in both lean (r2 = 0.79; P < 0.01) and overweight subjects (r2 = 0.92; P < 0.001). Conclusion: In humans, overweight is not associated with dysregulated expression of the intestinal FA receptors. Transcriptional control of the shortchain FA receptor, GRP40, and oleoylethanolamide receptor, GRP119, however, is likely to be positively regulated by a common regulatory pathway in the human duodenum during lipid exposure. This active study will yield new information on whether dysregulation of intestinal FA receptors, and/or their signalling, occur in humans with obesity.