9 months but only 7.5kg!!!

My baby now is 9 months but he's only 7.5kg! Every month he gets 300g and his chart age/weight curve is just below the lower curve of the chart. It's very difficult to feed him, he doesn't want to eat. Even drink formula milk (he only drinks right before sleeping). When he's not about to sleep, he prefers to play than to eat.
I don't know what to do now and I worry a lot for his health! I heard that there are some brands of formula milk that makes babies want to eat (Pediasure - from Australia). Should i change milk?

[Jaz1989]

Try pediasure. they come in 4 different flavors. strawberry,chocolate,banana, and vanilla. They are packed with calories about 350 i think. My son was like that put it in a to go cup and he'll tag it along with him. It acts as a meal replacer or just a boost to get him wanting to eat more. My son is 2 years old and drinks one a day or one every other day.

[littlebit667]

Good advice Jazi.  Another thought is reflux.  It often causes children to be uncomfortable with feeding.  Has he had problems with asthma, respiratory problems, etc??  

[Atchison_5]

I would try to figure out why he is not wanting to eat.  My daughter was teeny--13 pounds at a year old, and all they wanted to do was push more calories on us, even though she obviously had other stuff going on and the Dr just couldn't figure out what it was.  Shortly after a year I figured out that she could not tolerate gluten and she started eating and gaining weight as soon as we removed all gluten from her diet.  If your child has a food allergy or intolerance he will not want to eat becaue it will make him feel sick.  

[achilles2]

Your son might have food allergies. Such as gluten, soy, dairy, ect. You want to see if you can find a good pediatric allergist immunologist.