Patently false assertion. I'm ethnically a pacific islander who grew up on a small island in Micronesia and I can assure you that local island dishes are quite unhealthy.
It's easy to attribute dishes as healthy when just considering fish and taro, but this fails to acknowledge its traditional preparation with high amounts of coconut milk, salt, and sugar. Seriously, when was the last time you saw a nutritional facts label for any traditional dish? I can only speak anecdotally in that traditional Samoan dishes are not unlike Micronesia to the degree that Georgia Southern foods are clearly distinct from Alabama's flavor (that is to say they're not).
I think one of the biggest problems is the dependence of poorer remote islands in the Pacific on less perishable foods: think canned goods like Spanish sausage, Spam, sardines, Palm corned beef (from NZ), etc. or cheap frozen meats by the box, e.g. ribs, chicken, turkey legs, etc.
When I was growing up, my father would make the ocassional business trip to the FSM (specifically Palau). He'd bring boxes of frozen ribs and chicken with him and exchange for coolers of fresh lobster with his local contacts. Throw in a few cases of canned Budweiser and those business negotiations always turned out great. This might sound crazy to people who grew up in 1st-world countries, but it's a thing, and if you grew up on the islands as I did, then you know precisely what's up.
Just a couple of quotes from the article that my assertion is based on fact.
Experts say the region’s health crisis is primarily driven by a decades-long shift from traditional diets based on root crops toward ones that are high in sugar, refined starch and processed foods.
It is so wrong what is being done to exploit these nations by providing a food supply that is not, in the long term, better for health,...
As I've pointed out in a previous comment, when was the last time you saw a label of nutritional facts on any local dish anywhere in the Pacfic that allowed vetting of such a claim? When traditional preparation methods of natural foods are simply dismissed without consideration, it's easy to attribute these foods as anything but unhealthy. That's the misjudgement I see having personally grown up on a wee little-known island in the Pacific.
The quotes in the article point out the seriousness of the issue primarily driven by foreign food products high in sugar, refined starch and processed foods. I'm definitely in agreement with this claim, but it does not--indeed cannot--assert as fact that locally-produced foods are intrinsically healthy, and by that I specifically mean how they're traditional prepared.
Which begs the question: Was rigorous Western medicine on the scene prior to foreign influence that it was able to ascertain the health baseline of an indigenous population prior to its exploitation? If foreign dietary choices disappeared overnight, that doesn't necessarily mean that overall population health will realize some normalcy comparable to the rest of the 1st world. I believe there are deeply rooted cultural norms distinct to each island that have yet to be addressed.