|Oxidized Linoleic Acid Metabolite (HNE)|
"...In conclusion, oxidative stress or more precisely the level of oxidative damage to lipids and consequently proteins, as measured by free MDA and by HNE–protein adducts, was significantly increased in obese humans if compared to healthy controls."
"Measurement of HNE-protein adducts in human plasma and serum by ELISA—Comparison of two primary antibodies"
They were testing a mechanism to measure HNE levels, not obesity per se, but it's an interesting result nevertheless.
Obesity is, of course, correlated with the rest of the metabolic syndrome.