INS and metabolic syndrome: Although insulin has been reported to reduce circulating levels of AEA and 2-AG in a way inversely related to anthropometric and metabolic predictors of insulin resistance and dyslipidemia, without any specific information for PEA and OEA (36), in the present study, the finding of unchanged circulating levels of 2-AG and PEA after administration of palatable food and of all endocannabinoids after non-palatable food is possibly due to the inability of insulin to inhibit the biosynthesis, or up-regulation of the degradation, of these compounds in our insulin-resistant obese subjects (36).