Hi Opal, Here’s a site with accessible answers to some of your questions. http://depts.washington.edu/pku/diet.html The doctor will tell you how specifics about his formula, but this website should clarify what foods will be okay for him when he’s older. Also, here’s a really neat website with comprehensive information on lots of genetic conditions. It covers what it’s like to have the condition, what causes, how is it treated, how common is it, etc. http://ygyh.org/pku/whatisit.htm Happy reading!