if your doing it by mass, this will also effect the tall amongst us.

Being well over 6ft means that i'm naturally heavier than a 5ft something and generally struggle to fit within average size seating on aircraft. My issue is that of length rather than width.

I do what I can by getting an aisle seat, but its not exactly comfortable having knees wedged under my chin as the gap between seats as tiny and upgrades arent cheap.

Should you really penalize people because of their genetics?