Probably the main reason why Pacific Islanders are so big..
Epigenetics..
Isolated for so long from threat and danger... An unlimited food supply of high quality sources (pork, taro etc)
Taro is like the Island equivalent of Milk
Epigenetics is essentially what you do in your own life, and how it alters your individual DNA
So these fat fucks have had fat fuck ancestors after ancestors for hundreds/thousands of years
Then, research has shown that obese people do infact have thicker bones... This is because bone is a living organism and it adapts to stresses... Essentially Bones get thicker to accommodate heavier body weight.
Combine that with natural selection/warrior culture and it makes sense why they're so big