time out for 16 month old...

Thanks :)
I dont let him watch tv much, he watches it for about 15 minutes in the morning when i make breakfast and around 20 minutes in the evening!
We do try to be away from junk food as well. and he is really not screaming for 45 minutes or even 30 minutes... i walk away when he does start and usually it stop within 10- 15 minutes even shorter most of the time....
the only time i feel i have him thinking that i am giving in is, when i say that lets go for a walk and then I am putting on my shoes, coat and he is all ready to go and he is screaming to go and we end up going in 5 minutes or so....

but his teacher's concern was the screaming that he starts even its for 2 minutes but he does start it and then if he gets busy with something else....he will stop...
I guess my main questions is that is time out really necessary or right thing at this age?