Fear of fruits and vegetables - fear of spending the night with friend or relatives

Not sure what is going on with this, we were told he would grow out of it...almost 14 - no movement or change. Health is becoming an issue, but he is beginning to worry about obesity now as his body is growing. Not sure what the root of this is, but it may be in this SPD family. My other son has a strong case of ADHD. He is on meds and doing much better, but has a lot of the OCD symptoms described in SPD. Clothes much fit just right on his body. Any thoughts, we are exhausted trying to help my youngest.