On a recent full flight from HNL-LAX, there was a pax who was obese weighing about 400lbs. There was absolutely no way the pax would fit in the economy seat without taking up nearly all of the occupied next seat. The FAs didn't know what to do since there was no alternative place to seat the heavy set pax. Finally, the pax was offloaded and the flight continued. It made me wonder whether UA has a policy on what do in these situations. In fairness to UA, it would seem reasonable to make the pax buy 2 seats but I'm not sure that's a viable alternative for most people.