Does my 3 year old nephew have a eating disorder?

Basically what's going on is he used to eat a lot of food when he was still on bottled milk. Then he was taken off the bottled milk and his eating habits have changed drastically. He has no interest in food, and he has lost 7 pounds in 2 months. It's almost like he's controling his eating and anytime you try to feed him he looks at the plate and will freak out and shake his little hand "no" at the plate and run and hide. I am extremely worried for my nephew. Is it just a phase, or does he need doctors help?

Yes, something needs to change. At age 3 he should not be losing weight, and 7 pounds is substantial. Why is he not allowed to drink milk? Is he allergic? Yes, do make sure that he and his parents get a doctor's advice.

go see his doctor! he will want sweets!
Take him to a doctor.
My goodness, yes I pretty sure your nephew has an eating disorder. I would definitely take him to a doctor.
His doctor needs to see him soon. Does he drink milk from a sipper cup. He should have learned to do this before being taken off the bottle. Try the cup with milk along with the meal.