someone posted about anorexia. Our son has something very similar. But can Obsessive Compulsive Disorder (OCD) cause this? I can describe. He is always 5-10 pounds underweight. I would say closer to ten pounds at the moment. If under any stress, it jumps up to ten pounds. He will drink shakes to try to get his weight up a little ESP if he goes to ten pounds underweight, so that right there doesn't sound like anorexia. He is extraordinarily picky about his food. It must be healthy. And he eats small amounts. If something is healthy and delicious and not too fattening, he will actually eat a very large portion. But I can only think of two things that fit this description and one is a salad. He is very prone to suggestion. If a relative stops eating beef for example, he might stop eating beef for a year. He has resumed eating beef, but only rarely...not like he ate it before. He doesn't love veggies, so his choices are kind of narrow. He won't eat candy. On a rare occasion (his birthday for example) he will have a tiny piece of cake. He is clearly skinny , yet if you observed his eating habits/style other than those occasional shakes when he is very underweight, he eats like a person on a strict weight reduction diet. He claims he is trying to eat to gain weight. He even periodically records his intake and says he is eating 2000 calls a day. I'm on a weight loss diet and I don't see how this is possible. A little chicken and salad for example is not much dinner for example for a man. He eats very little bread and avoids fats like butter. Maybe this is simply a healthy diet for the most part. It seems a bit concerning that someone who is underweight would have so many restrictions. Is this all Obsessive Compulsive Disorder (OCD) stuff?