Even mainstream science has gone back a lot on the anti-fat pro-sugar trend. I agree there has been (and there always will be) big pharma and other interests at play, so gotta be very careful with science paid for by interest groups.

The thing with the scientific method is that it takes time to confirm if an anecdote is indication of a trend and leading to an actual measurable impact. So in a sense, it's good there are people who try this kind of extreme diets as they might give some indication as to which study should be done on large samples with proper control groups.

I prefer following the current scientific consensus (fat is not as bad as what they used to say, processed food seem to be the real culprit, no need to give your kid sugar tablets for energy as I was told in my childhood, etc) and adjust as new knowledge comes about.

One should also note that in terms of food it is always very hard to fully isolate one degree of freedom and say with full certainty that it is this lifechange that is causing all the benefits.