How body work is a complex subject indeed. But if you remember, this all began as a response to joshgel complaining that it's impossible to tell good advice from bad one.

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.