Hi M.!
I was just responding to another girl who's 11 mo old wont eat. I have a little guy turning 2 this week and BOY have we been through a lot of "phases" when it comes to eating. It's not easy, but there are tricks! A friend of mine has a son who was WAY small for his age, her dr told her to make him milkshakes, put peanut butter on things, get the instant breakfast type drinks to add in some calories.
Sometimes, with my son, I've had to just find some "staples" of foods that he likes and let him have them for the sake of getting food in him.
One thing I would caution you against is projecting yourself on to him. If you don't like a certain food, don't automatically not feed it to him... try everything. Even if he hasn't like it in the past, try try again.
Some things that might be good... Hand him a whole banana and let him go to town (of course watching him)... My son WILL NOT eat it if I chop it up, but will chow down if it's whole. (even when he was younger) The Del Monte cups of oranges tend to be something kids will eat... maybe cut them up into smaller pieces for him (watch out for acid daiper rash though, I can't give my son too much in a day). Eggo Waffles (I get whole wheat to try to be more nutritious) are good also. It seems that my friends who have boys and my son all tend to go towards being able to "Be big"... They like to hold big pieces and just knaw on them to their hearts content.
Krusteaz (sp?) has these mini pancakes that my son will chow on in the morning too.
Anyway... there are things out there that I am sure will get him excited to eat. Don't be too concerned though. My son doesn't weigh all that much more now then he did at his 1yr appt and that is normal. He's turning 2 on tuesday and he's 28 pounds. Just weigh him every once in a while and make sure he's not losing and try to get some higher calorie foods into him in the meantime.
Sorry if this isn't very helpful, I just put my son down and I'm 28 weeks pregnant and OUT OF IT! ha ha ha... Good luck, feel free to e-mail if you have any specific questions!
N.