i had same with my daughter when she was a toddler,so rather than make meal times a battlefield, for a couple of weeks i just used to randomly through the day leave healthy snacks,grapes,cheese,strawberries,bite sized pieces of pitta bread, bread with cheese spread etc dotted round the room then let her see me just pick the odd thing up and eat it with no fuss or attention drawn to it, within a couple of days she was doing the same, once she was happily eating more i just put one plate of food out, then slowly adjusted it to fit in with mealtimes and giving it ho her when we had meals.Its not the ideal way to feed a todler,but i was just happy she was eating lol.She is 17 now and still has a very small appetite,but she is health and happy,i often wonder why i worried so much,but hey thats called being a mum i guess :-) good luck,im sure he will grow up to be the same x