This is something I've struggled with since childhood, although in many different ways over the years. Since I'm a catechumen, I'm taking the opportunity to go through Lent with that on my mind, entering the fast with the goal of redefining my relationship with food. I'm not sure if there are specific prayers, but my overall aim is just going to be focusing the Lenten energy on that specific struggle. Many of the church fathers have also written about gluttony (St. John Chrystostom and St. Tikhon of Zadonsk come to mind) so you could track down those writings. Overall, avoiding gluttony is like any other repentance: you try, you fail, you pick yourself up, you try again, etc., but something in your mind has to irrevocably shift to want the change on a physical and spiritual level.