Something is making Americans fat as fuck. 

 Basically the theory is that pufa’s (seed oils) are dirty food (industrial sludge, non ancestral) which turn into dirty fuel when utilized for fat burn in the body. This produces unpleasant and negative feelings in the body and emotionally when fat stores containing PUFA’s are tapped into causing people to become hangry (distinct from hungry) and seek food more often resulting in overeating. Personally I find it a more compelling theory than sugar bad, sedentary lifestyle etc…