First coined in mass consciousness, as far as I know, by Alexander Lowen, creator of the mind-body-emotions therapy process known as Bioenergetics, this simple, direct statement - "The body never lies" - should change everything in the same way that the other Truths About Everything should. What Lowen extensively demonstrated in several seminal books, including, Language of the Body, was that our physical bodies "speak" openly and clearly, continuously and unequivocally to us and to others. If you want to know the state of a person's inner life, beliefs and attitudes, even their emotional, physical and psychological history, you can literally read their body language like a book.
Well, there is another way that the body never lies, and that is through its genuine cravings for whatever it needs in the way of nourishment and physical support. Now, I emphasize the word "genuine" for a reason. Many of our so-called cravings do not initiate with the body, but rather in the mind, and more specifically, in the ego.
Here's the way that works - if a human being is chronically sad, for instance, which means that there is stockpiled sadness caused by unreleased grief from childhood being held in the body, the ego will take the need for emotional comfort, for getting some "sweetness" out of life, and seek a substitute fast fix solution for the problem. One such very common fix, readily available in our culture for the above reason, is... sugar! Yeah, sugar, and in large and then larger doses, too!
You see, the problem is, whenever any kind of food, substance (drugs, alcohol) or activity (work, sex) is employed as a substitute for an emotional need, addiction ultimately results because the external thing isn't meeting the true need, so more and more of the thing is sought after. ("Just one more cupcake, shot, bump or hump and I'll be nice, right?" Nope.)
Okay, back to the point of this post. The body is essentially a receiver and a messenger. It receives information from the various organs and systems that comprise our physical selves about what is currently needed for optimum health, and it transmits that information through cravings and intuitions to the mind, ideally bypassing the ego. (See the FPL post "FULL PERMISSION EATING" for more details.)
In other words, if you have done the self-work necessary to be in touch with your emotions, and therefore with your body, you can trust your desires, and you will not be prone to excess over time... once you get used to the freedom! And you won't need to rely on medical doctors or nutritionists or books to tell you what you need. You'll sense it, feel it.
So, recently, I started having a craving for oysters and anchovies and broccolini, finding their tastes and textures irresistible. That was the craving part. And I trusted it. I even found a guy in a fish market who would shuck the oysters for me... after a few attempts to do it myself, resulting in a couple of nice holes in the palm of my hand!
Simultaneously, I noticed I'd been getting a lot of muscle cramps at night, recently, and that I wasn't sleeping well, either. That's where the intuition part came in. I put the cravings and the cramps and the erratic sleeping pattern together, and what did I get?
My body needed more calcium. Calcium deficiency was causing those classic symptoms of same, and it "turned out" that the foods I was craving were all good sources of calcium.
The body never lies!