Corn, beans and rice are first world problems of an American primal eater, ahaha. But seriously, there are way worse things that one can be eating. If they consume corn, beans and rice while the rest of their diet is clean, meaning no processed crap food, it doesn't surprise me that they are quiet healthy and live a long life.
yes, sugar has definitely crept into their diet (heck, sugar cane is grown there) in the form of soda and sweets, but not nearly to the extent that it has in the USA and other developed nations. I appreciate everyone's input--definitely food for thought (no pun intended!)