I can attest to this. I live in NZ, I have friends from the Islands, I've been to birthdays seen their relatives eating in a sitting what I would in a week. And aside from the fatty cuts of meat their meals consist of a lot of carbs and veg, so it's not like on balance it's just the lamb flaps that cause the problems, they just eat too fucking much. The weirdest thing is that there seems to be very little middleground, they're either overweight or they're impressively built, lean and muscular.