So poor people are healthier? By poor I refer to third world countries, where people can spend a day or two without eating, not in the West sense where poor means eating junk food.
There a lot of industrial diseases like myopia or bad teeth/jaws that they avoid but in exchange they suffer from different but more severe illnesses due to lack of clean water and healthcare.
I did not read the article so I can't give you an educated answer but my gut feeling is that this only works if you add high value food (proteins, nutrients, ...) after the fasting so that your body can then do something useful.
Only taking the food away or adding low quality food will most likely not solve anything