Hi Chantel
Well My boy was also on Nan & I switched to Nido. Just after he turned 1, I just switched to Nido. It is as filling as Nan, coz my lb didnt show any signs of wanting more milk.
He does drink a big bottle of 225mls at a time now, he only has about 2 bottles per day.
I was lucky that my lb took to the Nido & didnt refuse it. Im sure your lg will adjust fine with Nido, as it does taste yummy
Oh one more thing.... Nido has all the vitamins & minerals in it, even if your lg is a picky eater at times. My boy has his days where he wont eat much & than will drink a big bottle of Nido.