I have two DC 6 and 4. The 6 year old has low interest in food and is quite fussy - as a result he is getting increasingly skinny to the point I think he really needs to put on a few pounds. The 4 year is on the other hand has a voracious appetite, hoovers up anything put in front of him and certainly doesn’t need more calories than he currently gets.
How can I try to bulk up DS6s diet without DS4 getting the too much? I can’t rely on portion sizes as DS6 often leaves food on his plate.