It’s 3 p.m.  You have work to do but you can’t focus.  The pastry shop on the first floor is screaming at you.  Every cell of your being is pleading with you to run down and buy a chocolate croissant.

But you’ve decided to be strong.

You try to push forward with your work, but it’s a slog.  You’re barely making progress, in spite of what feels like Herculean efforts.

And all the while, the very physical sensations in your body are demanding that chocolate croissant.  You know that if you could just quell this craving, you’d go back to feeling OK and you could concentrate on your work.  But what about the promise you made to yourself about not eating pastries in the afternoon?

Your body says “This is no time to stick to the plan.  This is a special circumstance!  You can go back on your diet after you have the croissant.  You’ll feel better.”

“It’s all in your head,” you tell yourself.  “You’re not hungry.”

I know this scene all too well.  I’ve been there a million times, too.  And I’ve tried to persuade myself that I wasn’t hungry.  Real hunger feels different.  A craving comes from the mind, not the stomach.

Or does it?

It could be that there are certain bacteria in your gut that are hungry.  I think of them as little aliens in my gut.  Different microbes thrive on different foods.  If you feed the croissant microbes, those are the ones who will multiply and take over.   If you feed them celery, they starve.  And while they’re starving, they’ll trigger cravings in your body to get what they need to survive.

Meanwhile, the celery-loving microbes will have a feast.   They’ll get stronger and they’ll multiply.

According to IFL Science, gut microbes manufacture special proteins that are similar to hormones that regulate hunger.  In a sense, these microbes are telling your body what they need to survive.  http://www.iflscience.com/health-and-medicine/how-bacteria-our-gut-affect-our-cravings-food/

If your gut is full of celery-craving microbes that have no interest in chocolate croissants, sticking to your plan would be much easier.

You’ve probably experienced this yourself.  When you’re in “healthy eating mode,” after your body gets used to it, you find that you crave fresh fruits and vegetables.  You may have also found, during other times in your life, that the more crap you eat, the more crap you crave, and the less yummy fruits and vegetables seem.

Of course, this is a huge over-simplification.  No matter how many celery-loving microbes I have in my gut, I still enjoy the occasional chocolate croissant.  But it’s nice to choose when I want to have one instead of being at the mercy of aliens in my gut.