Yeah, ok, good point on the soy thing, however, we are looking at an entire race here, not an individual, and dietary things of this level are not typically race selective (we are talking about pretty fundamental biological processes that are common across all mammals). In short, unless Japanese people react differently to estrogen, it is incredibly unlikely that the estrogen-like compounds in soy would affect them any differently from anyone else.
Now, you have a much better argument in the fact that we don’t have any studies proving that they are not affected by those compounds, however, I think that it would be a bit obvious if they were. I mean, the most serious concern is male breast development, which is something that has never been observed in Japanese males. If the problem is not significant enough for us to know about, it is probably not significant enough for us to care about. (Keep in mind that studies like this are conducted by feeding rats enormous amounts of the chemicals being tested. To my knowledge, no study on this has actually been done on humans, and the quantities required would scale to the point of absurdity. In short, even if this applies equally to humans, you would probably have to consume large amounts of the chemicals themselves, extracted from soy, to see any effect.)
And no, I am not aware of any studies. In fact, I am not aware of any studies on this subject targeting humans at all. Rats are typically used, because they have similar biology to humans, but doing this kind of study on humans is ethically questionable. So, all they would have to go on is observation, and thus far I know of no studies that have observed any negative side effects of consuming soy on humans. (I have not looked into this in a while, so it is possible there are some recent ones. That said, I suspect we would have already heard about any that turned anything up, given the publicity it got when scientists only theorized that soy might cause problems.)
I found a source for the 40% thing yesterday, but I don’t remember were from (and I don’t have time to find it right now). It looks like percentage of calories from oils ranges from around 30% to 40% on average though. It is as low as 25% in some places, and as high as 45% in others. The 60% I believe I read in a study done in Australia, and it was not a regional average. They had a number of individuals within their sample that consumed that much, and none of them had any health problems related to it. The study ultimately recommended lower fat intake than that (based on the minimum recommended intakes for carbs and protein), but not a lot lower (wish I could recall; the minimum values left a lot of room for flexibility).
I don’t know anything about alcoholism over there at all, but that is an interesting question. I wish I could help you (and frankly, now I am curious).
And I am curious about keto diets as well. I have heard a lot of unsubstantiated claims, sometimes from doctors that seem more like quacks, but I have not seen any serious studies on them. Most of what I have seen is personal experiences, which show only that people exist who can survive on a keto diet. I kind of suspect they are similar to vegan diets. Many people can handle them, but a significant number get seriously sick from a vegan diet. (I have a friend who’s sister tried a vegan diet, and she did all the research to do it right. She ended up very sick, and in the end she gave it up. It only took around a day for her to start recovering once she started eating meat again. It was not a religious or ideological thing. She thought it could help with some minor health problems she had. It turns out this is not uncommon, though many people get sick because they don’t do it right.)