There may be a link between the obesity epidemic and endocrine disruption and metabolic interference. Studies conducted on mice exposed to phthalates in utero did not result in metabolic disorder in adults.[49] However, "in a national cross-section of U.S. men, concentrations of several prevalent phthalate metabolites showed statistically significant correlations with abnormal obesity and insulin resistance."[49] Mono-ethylhexyl-phthalate (MEHP), a metabolite of DEHP, has been found to interact with all three peroxisome proliferator-activated receptors (PPARs).[49] PPARs are members of the nuclear receptor superfamily.