I'm not proposing that every person invents own diet, just to use common sense if a diet works for you and another doesn't.
As to how to identify who's lying, how about people telling lies? When Atkins wrote the book in the seventies, his critics told that his diet didn't work and provoked a series of terrible side effects, none of what was true.
The fact was that thousands of people were trying the diet and it worked and it didn't make them sick. So where did the criticism come from? You can tell me that there are unknown risks and ask for caution. But if someone is saying in no uncertain terms what they said in the face of evidence, that's a strong indication that they have no interest in truth.
Of course, diet is not the only matter in what some powerful entities try to manipulate the public, it happens in a variety of matters where science, politics and private interests meet. The first principle here is follow the money.
It's funny that you should bring up Atkins and then suggest "following the money"... Atkins Nutritionals sued some of the people that you are labelling as liars, and lost all of their lawsuits. If there's one thing I've learned from my two decades living in America it's that when a corporation loses a lawsuit to individuals here, the individuals are probably barking up the right tree.
Have you considered the possibility that what you are terming "liars" is just "people that disagree with my strongly-held belief"?
> choose your poison: do you think it's safer to be fat?
This is a false dichotomy. The choice is not keto or obesity. And losing/maintaining weight is one of the short-term & measurable goals I was alluding to. It's trivially achievable in a fairly short time with various approaches and keto is certainly one of them. Many of the others require less self-discipline than keto however, and a number of those have orders of magnitude more man-years of aggregated long-duration testing behind them.
> But don't believe the army of liars that's been spreading FUD consistently over the years.
That's good advice, but how do I identify which one is the army of liars and which one is the army of truth? :)