The key is consistancy...if you sometimes give in and sometimes don't, he wont get the message that mealtime is when you eat. You may have to cut out the snacks between meals if you are giving them to him now so he will be hungry enough at mealtime. Water and milk throughout the day will keep him going like Rachel said and nothing with sugar or high fructose corn syrup in it...these things will affect his appetite...even fruit juice should be limited to about 6 oz a day and cut with half water if they are not big on drinking water alone. It may take a week of following the routine to see results, but he will eventually get back on board when he gets hungry. Toddlers are funny eaters anyway though, some days they wont hardly eat anything and other days you can't seem to fill them up, lol, that is how my 3 yr old grandson is. I keep baby carrot sticks and ranch dressing, pretzels, apples and I grill a couple of extra chicken breasts to have on hand and even if he doesn't want what is for dinner, he sits with us and can eat those things and get nourishment from them. Finger foods are great for your son's age where they want to touch and feel what they eat and feed themselves. Hope this helps.