I want a diet chat for 12 years old child.
What should we eat in our :-
Breakfast
Lunch
Evening snacks
Dinner

A 12 year old should not be on a diet to lose weight ( if that is the type of diet you are discussing) without consulting a doctor for over all health issues.

Too many 12 year olds are skinny and think they are fat.

But a well balanced diet and exercise like for anyone