What causes a sudden growth spurt in 4 year old cat causing physically bigger and heavier including head and face?
It's probably just a sign of maturity the same as 30 yr old men sometimes fill out a bit when they reach their prime, very often so do cats, if your really concerned ask your vet but in most circumstances this is normal X
Well technically weight has nothing to do with "bigger" but what I think your looking for it heavier, and 900 is heavier then 1 gram. Although if you're some sort of psychotic guy and is in fact looking for what is bigger. 900 grams of something would be bigger if it was the same object (without compression)