Thanks for responding Gary. They throw away both sweet and salty. What is BM please?

I recommend researching the way autism effects eating disorders. This is just normal behavior for someone with disordered eating. It’s not exactly a product of autism but it does contribute. Here’s some advice; get your kid a good therapist. Find them someone who will first help understand why they feel that way and how to overcome it. It’s very common for teens at that age to develop disordered eating habit and struggle with identity like in your childs case, gender neutrality. I could go on, but your child's behavior is pretty common in kids around 12-17 and has close to nothing to do with ASD. My daughter had a similar phase around 13-15 and it was really tough for her especially with the gender struggles . You see, disordered eating patterns are a sign of other mental illnesses having to do with a difficulty to accept oneself. In this case, puberty. Kids with autism experience puberty much differently and it’s known to be the most tormenting experience for them. The main reason why is change. Change is really hard for kids with ASD, and that’s something that parents often forget. Changes in the body are very difficult for them to deal with which causes the struggle with identity and image in turn causing eating disorders and many other mental illnesses. Like I said before, finding the appropriate help for your child is important but keep in mind it wont be easy. My daughter has a clear aversion to therapy because she doesn’t get anything out of the ones that don’t actually help her, she knows this, and never wants to show up for sessions because no therapist understands her case. So keep this in mind, get a therapist who has experience with ASD. It’s been a while since you posted this but I hope I could have been of assistance.

@A MyAutismTeam Member B.M. is Bowel Movement, Pooping.
Sounds like you have a 'Blan' eater on your hands.
Some think that it's easier, but it's not, it means that you have to avoid adding anything to their meals, but may I suggest adding Butter/Margarine to foods like Oatmeal and Baked Beans.

Mentioned Users

A MyAutis...

It could be a texture issue.
Do you know their food preference?
Are they a 'Sweetie'? (Preferring sweet foods)
Are they a 'Saltie'? (Preferring salty foods)
Are they a 'Blan'? (Preferring neither sweet or salty foods)
Maybe it goes deeper into their Psyche' and they need professional help.
Are regular B.M.'s a thing with them?