Ds & food. What more can I do?

[Seniorschoolmum]

I have a year 8 ds and recently it became clear that he is much skinnier than his class mates.

He eats burgers, sausages, pizza etc & likes fruit & veg but has a small appetite. He deosn’t like food with sauces like curry and doesn’t eat many sweeta although he does like cake.
He has plenty of energy and seems healthy but he is so skinny his shoulder blades poke out. A couple of people have commented and I’m starting to worry. What am I not doing?

Is he actually underweight? In relation to his height? Is he very active? Perhaps his classmates aren't at healthy weights.

He’s down at the bottom edge of the 25th percentile.

He says he has enough to eat. I try to ensure his food is well balanced, plenty of protein and carbs. He’s also the smallest in his class although me and his df are both above average height.
The comments, coming close together have got me worried.

Very likely a growth spurt at that age. My cousin was painfully thin between 13-16 and is a normal man now. Keep feeding him what you are and don’t panic.

My DS is and has always been the same. He's now 13 and will eat an adult portion but is painfully thin (currently off the bottom of the percentile chart). However since he has plenty of energy and is very healthy i don't worry about it too much. I try to sneak in extra calories when i can - like letting him have milkshakes when we're out.

Just ignore the comments and keep feeding him what you are doing.