Joopz / Itsy,
Like I always said, look at the growth chart as a whole. Don't compare with others, just monitor his own chart. Then you don't have to worry much. If you remember sandwich, she shared that the PD picked up his #1 physical developmental problem using the growth chart. Imagine if she didn't keep track of his growth in growth chart. It's important to monitor the growth chart, but NOT to compare with others, and NOT to worry how heavy or how light he is.
Children don't inherit parents' size, it's not like parents is small size, children are going to be small size. There are children who are big while their parents are small, or vise versa. Though they did get the genes from the parents, but the size of a kid (ie, weight and height) are very complex traits and the genes are quantitative and not qualitative, and it's largely affected by nutrition and exercise. Though in general, if one of the parents is tall, the child is most likely not going to be short, cos tall is the dominant gene. But for weight, there is no dominant gene. So the kid can be heavy or light totally independant of the parents.
I am not so sure about pedisure. How would it help to fatten up a kid? How much different it can be from other brand, it's not like they can anyhow add in things right? Don't know, maybe you can compared the nutritional values of Pediasure with other brands and see what's the different?