OMG I was almost in tears reading this thinking that you might be a terrible mother. What does that make me. My daughter just turned 3 last month and she only weighs 22.6 lbs. Some kids are just SMALL. I know that our DR has always been concerned about her weights and we have met with nutritionist, but if they won't eat then what do you do. PLEASE don't feel bad. My nephew was very small and he would eat NOTHING until he turned 5. Now he eats EVERYTHING. He is still very small, but you seriously can't feed the boy enough. My heart is bleeding for you, please just love your son for who he is and don't get down on yourself. If your doctor makes you feel bad then GET A NEW ONE!