aghast
We don't understand them perfectly, and many people (maybe more than half the world?) don't actually measure out their hunger in grams and milliliters, or understand the fundamental building blocks of metabolism at the chemical level, and get buy just fine, purely trusting their guts.
One size doesn't fit all, and sometimes cravings are correct, but not all the time. Addictive substances and microbes show us that "what you want" isn't always "what you need."
Opiates have been around for centuries, and demonstrate that just because you might feel a hunger for something and find it satisfying doesn't mean it's good for you. You're body's understanding of the world around it can be distorted. Sometimes the things that distort it's intuition are odorless and colorless. Natural food does not come with labels (and even labels can be wrong), and if you're uncertain of the purity of the water you boil your meat in, well, maybe there could be something in it that is sapping and impurifying your precious bodily fluids.
Meanwhile, it might be counter-intuitive that bread mold can ward off infection, but then again we have penicillin which has proven to be a powerful and valuable anti-biotic.
So, feel free to operate on faith and emotion, but going through life with your blinders on, you might be caught off guard by things that you could have avoided if you hadn't chosen to ignore them.