Actually... all kidding aside... What Im trying to express is that a man of his size, with some weight can in fact wield a knife without a problem
What are you talking about? Anyone with an arm and a hand can wield a knife. It's not that difficult.
I've seen skinny little upstarts no more than 130# cleanly slice the dickens out of water bottles, etc. And I've seen big, chunky, if-it-ain't-fried-it-ain't-food redneck-lookin' guys do the same.
I'm 6'4" and 205#; BMI indexes may tell me I'm overweight but screw it, I feel good and can usually move around real quick at the tender young age of 38. Just not for very long
When I was 260#, forget it, I got winded opening a bag of chips
Whether or not I was a fat ba$tard had no bearing on my ability to abuse a side of beef or make a mess of cardboard.
I agree that it is a sad state of affairs when we start judging people, or placing value on people by their looks/weight.
Just to play devil's advocate

....
Would you hire a phys ed teacher who was wider than he was tall?
Would you trust a woman in a loincloth and 6 months of jungle-funk to sell you a house?
Would you agree to watch a suitcase at the airport for a bearded man in a turban?
Would you date a woman who was amazingly nice, but astoundingly hideous? How bout if she was ridiculously wealthy? (switch the gender, and this one gets the ladies in an uproar... how many attractive, smart women date fat, ugly, broke guys?!?)
Go ahead, y'all tell me you don't judge people on appearance.
Again, just playing devil's advocate, please don't take anything personal.