I am the mother of three boys and have lots of experience with eating issues. My youngest, who is now 4 would only eat fruit when he was 2. My middle one, now a teen, only ate pb&j. If your son does not have a medical problem, as many mentioned, perhaps it's just the normal phase of 2 year olds that prefer only one food, or type of food. I've heard of many children only wanting a very limited diet at this age - someone I know son only wanted eggs and nothing else, another girl I know will only eat dry cereal and yogurt. Check the medical possibilities and if it's nothing - don't worry - they grow out of it.