As a trained anthropologist just let me say this:
There are no early accounts of polynesians which describe them as being fat. None.
Like other ethnic groups, it appears that polynesians don't do particularly well with modern food preparations. If Jabari comes here and follows Derrick and Gordo to subway for 4 foot-longs a day, then that wouldn't be great (it's not good for Derrick or Gordo either).
I have no doubt that if Jabari is motivated to have a big svelte body, then he can do it. He needs a good nutritionist.
(BTW, why don't more of these millionaires have specialized nutritionists?? For me, this is probably the most surprising thing about the NBA... this is one area where a lot of players could improve).