Just set all the fat people next to each other. Make them sardines. 😁
Don’t put them all on one side of the aircraft!
It’ll just fly in circles............
The harsh reality is that weight and balance matters for aircraft flight safety. I've been on small twin turbo aircraft where a game of music chairs was played at the gate to move the fatties around after the luggage was fully loaded. Rearranging the 250 lb to 400 lb passengers is critical to safe flight. The "standard passenger" for FAA seating is based on 180 lb persons.