[quote]WestCoast7 wrote:
Eat more, more often also, in addition to training. This will help speed your metabolism up.[/quote]
Great advice, for many people.
However, I don’t think he needs to speed up his metabolism. He needs to slow it down, like I do. I’ve been focusing on stuffing myself, 4 times a day (up 12 lbs in just over a month approx. [however, like OP, I was underweight, so hold the applause]). His belly just isn’t that big.
My breakfast this morning was:
10oz+ lean ground beef (we bought a side of grass fed beef, otherwise, I wouldn’t be scared of medium ground beef)
1 cup of almonds (yes, 800 cals worth)
2 eggs my son didn’t eat (he ate 2)
1 kiwi
1 orange
2 tsp (teaspoon, not tbsp) of fish oil
a couple digestive enzymes
and maybe ;), 3 homemade peanut butter cookies (peanuts, egg, sugar, that’s it).
If I wasn’t running my 4 yr old to school, I probably would have ate more.
On my non-training days, I add in more carbs, as too many make me groggy!
Oh look, it’s dinner time! 
[quote]dgallagher88 wrote:
I’m hoping if I build up more muscle it won’t appear to be bigger than everywhere else.
[/quote]
As Westcoast7 said, provided you don’t have any digestive issues, this should be the result!