How do i get my dog to stop chewing and eating everything?

I have a 13 month old Westie (West Highland Terrier) named Simon. He's adorable, loveable, and sweet, but there is a MAJOR problem. he chews everything! he eats shoes, chews, on plastic, he has ruined tons of dog toys, and even ruined a doll. I don't know what to do, my mom told me that maybe he's just a puppy and he'll grow out of it, but he hasn't and he's already a year old. Any advice would be helpful,thanks:)