Dailymail lol.
Anyway, while in principle it makes perfect sense, in reality you penalise tall people who already have to suffer the lack of legroom (like myself), penalise muscular people (like myself)... so do you do a calipers test?
I will say though that if you are too fat to fit in one seat pay for two. I was stuck beside a fat fat piece of shit on a flight to France en route to Brazil and his fat triceps and sweaty back were on my body. I elbowed the cu nt (6am flight) til he moved over and the fat shit slept til the stewardess walked by with muffins - at which point he rose up and grabbed a handful.
I changed top in Charles de Gaulle airport I was so disgusted that his fat sweaty cells had touched my clothing.