I give mine (same ages) about the same. Both have what I would call fairly good appetites. DS would have eaten more at 13 months than he does now though (so more than DD) but I think he is eating quite a lot for a 4yo eg for breakfast they both had 1.5 weetabix, a large pot petits filous and a slice of toast. Only difference DD had full fat milk and DS has semi and I cut the crusts off DD's toast.
Mine both eat loads. We no longer buy ds1 (nearly 8) a "children's meal" because he eats as much as (or more than us), and also because he prefers "proper food", rather than what's usually on the children's menu.
DS2 (6) usually opts for chicken nuggets and chips [despairing grin]