My husky looks really skinny and it bothers me, any tips? (pictures inside)

So my husky is about 4½ months now, hes happy, active, loves to cuddle and play and seems to be fine.

It bothers me that he looks so skinny, according to the things I've read, he has the weight hes supposed to, he weighs around 13-14 kilos.

I feed him twice a day with this special concentrated puppy food, according to the food, I should give him 100 grams, twice a day, I'm however giving him 150 grams twice a day + treats and stuff.

He doesn't seem hungry, he doesn't beg for food at all, when I'm eating dinner or something, he couldn't care less. of course he gets excited when it's feeding time, but otherwise he doesn't show any signs of hunger. I'm thinking about upping the food dosage to 3x 150gram a day instead of 2x 150 grams, any pointers on how to get him fatter?

Here are some pictures of him: http://imgur.com/a/uOwIZ