5 yr old regularly does this, she's hardly eaten anything today and now saying she doesn't want any tea. She's not ill, been very active all day in the park. If I don't feed her now she won't get anything later, she knows that and to be honest never asks for anything later. Maybe she does just have the appetite of a bird, and I know eventually it all evens out, but it feels all wrong to send her to bed with absolutely nothing. Today she's eaten 1 chocolate chip brioche and one half of a cream cheese sandwich. That's it. That can't be right can it?
I've always taken the view that any child offered three meals a day won't starve themselves so haven't worried tbh. Dd has the appetite of a bird and always has ha. At 12 she's small but healthy, she has eaten a slice of chocolate cake and just agreed to a pastie for dinner,I doubt she will eat it all but she ate well yesterday so not too bothered tbh.
My older dd is 22 and still can't eat a full bag of crisps. She has always had a small appetite as well. They eat what they need IME. We would all have been miserable if I had made mealtimes into a battle, as it is there is no stress or anxiety and neither of them have starved. Dd1 is 5 foot 2 and size 6 and dd2 is probably going to be about the same size. Dd1 is taller than I am and I suspect dd2 will be too so they are the height they would be expected to be.
I say "okay, you can go to bed with a hungry tummy".
And we leave it at that. It helps that I never offer snacks - the merest whiff of a biscuit can put even my older kids off their lunch. Mine are all growing just fine, but sometimes aren't hungry. I know they'd eat if offered something like a cheese sandwich instead of say vegetable curry, but they need to learn to eat a balanced and varied diet, so if they stop eating the curry after a forkful I'm fine with that - they'll eat more if they're really hungry.