I'm not sure of you have an access to a mall on the island. If you do, go to a SUYAKI restaurant called MK.
There, you have a variety of meat and vegetable and anything you can think of.
Or you can also find a 'street' version of it called 'MOO GRA TAH' -- ???????? (asked the local). Now this one is all you can eat. You pay 85-100 baht per person, but you can eat as much as you want....well, it's all you can eat. You should be able to find this on the street.
There, you can order as many meat as you can. It's pretty like 'Fondue', but except for dipping in sauce, you dip the meat or vegetables in a boiling water or grill it on top of the 'pot'(?), let it cook, take it out on your plate and eat it with any available sauces
Or you also can eat 'GAI YAANG -- Grilled chicken
YUM NUA -- Thai BBQ Beef Salad or you could also order YUM GAI instead which is Thai Chicken Salad.
Especially while you are on the island, you should be able to order any type of fish dishes. And trust me, you get a whole fish just for yourself.
We have dishes that are protein rich, you just have to know what to order.
VVV BELOW VVV --- MOO GRA TAH