Hello!
In this age it's a very common concern. If there's no other symtoms and a child is rejecting feed, that simply means at the moment he doesn't want to eat, so do not force feed him, just wait try after sometime
Next Steps
If you feel his weight and height are less compared to peer group, plz consult online
Health Tips
The same foods every day can be monotonous to a child.....since he is 15 m, so food options are more,u can change the diet regime intermittently