you poor thing. Worrying about weight gain or lack of it has got to be one of the worst things that a Mum has to endure.

My DS was born on 25th % and dropped to 10th after birth and has stubbornly stayed there. Nurses were a bit concerned in the begining as we had issue establishing breast feeding but looking back now I realise that he had just settled into his curve. I know his drop is smaller than your DSs but it could just be his "real" line. Havent heard about adding oil to diet but we tried offering all the usual fatty foods etc to see if it would bulk him up but didn't work. At 8 months your DS is probably also starting to be a lot more active than before all of which will burn the food that he consumes which will slow down weight gains.

Hang in there until you speak to your paed but try not to stress too much. I keep repeating it to myself they won't let themselves starve. And I now accept (took me 2 years lol) that he is what he is. A very busy active 2 year old who doesn't have an ounce of fat on him who eats when he is hungry and doesn't eat when he isn't (or when there's something more exciting to do : lol: )