The difference from before sugar and processed food in Thailand, is they eat natural rice to every meal as before, but they eat more meat especially pork, and added processed ingredients, which leads to much more calories. Their weight gain have nothings to do with rice, same as potato do not have anything to do with obesity in the west.
Ballanced diet is nothing new, and certainly not invented by processed food inventors. Balanced food is natural seasonal food from what was available in the old days.
It is as simple as we had one day a week with snacks and sweets which was saturday, and one day with desserts sunday! We ate healthy all year based on seasonal food available. Thats maybe a different meaning in other countries such as Usa, who maybe was first out with industrialized food, and Thailand maybe one of the last. I see big difference from 20 years ago and today here in Thailand, and how all food have changed even street food.