I once had a fat cat. (Rascal) I'll give him fame.
My friend said you should put him on a diet.
Years later at age 17 I could put my hand on his back and touch my middle finger to thumb he was no more than a silver dollar sized.
In the end I was glad I let him enjoy life. No diet. Let him eat what he wanted. Cat never heard of a diet. He just liked to eat a bit more.
And in the end he lived as long as most of my cats do.
I learn from my cats as I see the entirety of life. We will all be skinny soon enough. Real skinny.