DS never had formula at all. He just refused it, so good job I stayed off work lol.
He had cow's milk from 9 months (go on health authorities shoot me) although not as a main drink, like I said, he still had breast milk til late on. he does like his milk though I have to say. He has at least a pint a day. Usually a cup in the morning and a cup in the evening now. Sometimes he has one in the day too. Also, before anyone says anything, cutting back on milk made no difference to how much he ate either.
If the energy is there I wouldn't worry, certainly never any concern for my DS there.
Not only does he not eat a huge amount, he is very very fussy. I tend to ignore it now to be honest and just put everything on his plate anyway. If you offer him something, he will always try it (unless he is in a bad mood/tired), even if he then spits it out.
He has always always hated carrots, right from being tiny. I mostly made food for him but sometimes I would give him a jar, but he never ate them as they always contained carrot! In the last fortnight, he has started eating raw carrot, so a break through there!!
I can't do anymore than I do, he doesn't eat cake or biscuits or hardly any chocolate - not because I don't let him (I have no hangs up about any food, everything in moderation) but he just doesn't like them!!
If you are as chilled as you can be, it will come through in him too. I weighed DS today at home and at 2 yrs and almost 2 weeks he is 24 and a half pounds!! I had a look and when he was 13 months he was 2lbs 11, so at min he is Still in the weight range for some rear facing car seats
Hope you are ok