Japanese people generally don't skip breakfast and eat rice with every meal. So they aren't doing intermittent fasting and they are constantly eating one of the foods TFA says not to eat.
I am not saying it's bad; eating fewer calories has its benefits. However, the effectiveness of intermittent fasting, especially as portrayed in the media, has been quite overblown, IMHO. I think one of the main sources of this is from a study that suggested longevity improvements in lab mice. Unfortunately, studies involving lab mice, especially those concerning metabolism, translate poorly to humans.