Should i change..........?

ok im a 14 year old boy 5'6 and weigh 415 pounds. my dad is also over weight (but hes only 250 pounds) , and my mom and 16 year old sister are really skinny. We are a Tongan family (we live in Hawaii btw) and in our culture being fat is a good thing. my parents encourage me to gain weight. in Tonga fat people are well respected and are considered attractive. i do have a GF. she is also Tongan and shes really short and thin and she is gorgeous and she loves my body. she always wants to cuddle with me and she loves giving me belly rubs. anyway the food we have is always unhealthy and my mom makes a lot of it. my mom gives her self, and sister small portions, my mom gives my dad regular portions and gives me a HUGE plate of food. so for a typical dinner i eat maybe 4-5 plates plus what ever is left over. when i was younger my parents force fed me and made me eat alot and if i didnt i would get in trouble, but now they dont force feed me any more i just eat a lot on my own terms. dont get me wrong they are good parents and they give me a lot of support and love, its just they they were raised to believe that fat is good. i do have a food addiction. when ever they bring me the big plates of food i cant help my self but to eat it all and when my mom goes grocery shopping and she brings home junk food i will eat it all. like yesterday i ate a whole box of Twinkies and for dinner my mom desided to order pizza and she ordered 4 large pizzas. My mom and sister had only 1 slice each and my dad finished the rest of that box and I had 3 whole pizzas all to my self. i was actually full after 2 1/2 pizzas but my dad just kept saying "eat the rest so we dont have any left overs" i just said what the heck and ate it all and then my dad said "thats my boy" as if he was proud. I am actually a competitive eater (im no pro, I just compete in local places, and I hold a few records in some places) when it comes to junk food i have no self control. like i said before for health reasons i would like to lose weight, but i dont want to disappoint my parents and i want to keep true to my culture. i am proud to be a Tongan and am proud of to be fat. i care alot about my culture and if i lose weight i will go against my culture. i love food and i love to eat. in a perfect world i would be over 400 pounds and still be healthy, but thats not possible. I want to be fat, but I don’t want to die young. so what should i do?