Myth: There is one right "way" to eat, and once you discover it, you're going to be slim, happy and healthy.
Truth: Because people's bodies and goals are different, "right" and "wrong" can be completely different for different people.
So there are diets that say to eat no carbs.
And then there's diets that say that to eat carbs, but only when you balance them with protein.
And then there's diets that say to eat carbs and protein, but never at the same time.
What's going on here? Why can't anybody agree?
What you have to remember is that different diets have different purposes. They're each trying to make your body do different things.
For example, a lot of the "no-carb" diets are trying to trigger a specific reaction in your body--a thing called ketosis. The entire goal of this type of diet is that one single thing. Dieticians disagree about whether ketosis is a good thing or a bad thing, but they all agree a no- or low-carb diet will get you there.
The types of diet that require you don't eat combinations of food--they usually say to eat nothing but fruit until noon, and then make sure time passes between when you have carbs and when you have protein--are actually less about weight loss, and more about keeping your system clean. Since different chemicals are required to digest carbs than protein, your body can process them faster if you only throw one of them at a time into your system.
On the other hand, diets that ask you to eat foods in combination are trying to do the opposite--since digestion burns calories, the longer the digestion process takes, the better. Combinations of food slow the rate of absorption into your body, giving you the chance to burn that energy before it gets stored.
So if it seems like two food statements are in conflict (This article says I should eat broccoli, but this one says I shouldn't) stop and look at what the reasoning for each statement is. A difference in recommendation is usually because of a difference in goal.