Yesterday, I was doing some meal prep for the week, which meant spending a good part of my day in the kitchen. While washing blueberries, I popped a couple into my mouth. While making pumpkin bread, I tasted a little batter from the spoon. I was roasting pecans for a healthy recipe I was testing, so naturally, I sampled one. Later, I grabbed a few Brazil nuts, sat down at the computer, and got to work on a coaching plan for a client.
Nothing particularly outrageous about any of that. I was eating real, whole foods, creating healthy recipes, and going about my day. There was no bag of chips, no box of cookies, and certainly no resemblance to the food binges that were once part of my life. But when I thought about how many times I’d put something in my mouth without actually sitting down to eat a meal, I realized something interesting. My digestive system had been getting little deliveries throughout the day, whether I was hungry or not.
After losing 140 pounds and spending years changing my relationship with food, I’ve become much more aware of why, when, and what I eat. I rarely eat after 3 p.m., a considerable change from the days when a bowl of ice cream before bed was practically a nightly appointment. Yet there I was, still finding little opportunities to eat throughout the day. It wasn’t a binge, and I wasn’t particularly concerned about the calories. What interested me was something I hadn’t really considered before: What happens inside my digestive system every time I take another bite? And more importantly, what happens when I stop?
Your Digestive System Has a Schedule You Probably Never Knew About
Most of us understand the basics of digestion. We eat, our stomach gets busy, nutrients are absorbed, and eventually our bodies deal with what remains. We tend to think of digestion as something that happens because we’ve eaten, which makes sense. But there’s another process happening between meals, and until recently, I’d never even heard its name.
It’s called the migrating motor complex, or MMC. Not exactly a name that rolls off the tongue, and certainly not one that’s likely to come up over dinner. But this fascinating process helps move residual food particles, secretions, and bacteria through the stomach and small intestine during periods when we’re not eating.
Think about how much attention we give to feeding our digestive system. We talk about fiber, protein, fat, probiotics, fermented foods, carbohydrates, digestive enzymes, and which foods support a healthy gut microbiome. All worthwhile conversations. Yet there’s an entire pattern of digestive activity that occurs when food isn’t arriving, and most of us have no idea it’s happening.
The MMC operates in repeating cycles during fasting, generally lasting around 90 to 120 minutes. Its activity includes periods of relative quiet, irregular contractions, and a short phase of stronger, coordinated contractions that travel through portions of the stomach and small intestine. These movements help transport remaining material farther along the digestive tract.
And here’s where my blueberries, pumpkin bread, and pecans become relevant. Eating switches the digestive tract from its fasting pattern into the activity associated with processing a meal.
That doesn’t mean one blueberry causes a digestive disaster or that the gut stops moving altogether. It means eating changes the kind of work the digestive system is doing.
I had been thinking about food in terms of nourishment, ingredients, and how my body responded to what I ate. Now I had another question to consider: was I allowing enough uninterrupted time between eating occasions for this other digestive activity to take place?
Meet Motilin, the Hormone I Didn’t Know I Had
I’ve written about hormones before, particularly the ones that influence hunger, fullness, metabolism, and weight. In my article Hormones That Affect Weight: Get a Grip on Them Now, I explore several of these chemical messengers, including ghrelin, leptin, and insulin.
But motilin? That was a new one for me. Apparently, my body has been employing this hormone my entire life without bothering to introduce us.
Motilin is produced primarily in the upper small intestine and helps regulate the MMC, particularly some of its strongest contractions. During fasting, motilin levels rise and fall in cycles, helping coordinate movements that push material through the digestive tract. It’s part of the complicated communication between our digestive system, hormones, and nervous system.
And motilin has another interesting connection: hunger. Research suggests that certain MMC contractions, particularly those originating in the stomach, are associated with increases in hunger sensations. So that familiar stomach growl may have more going on behind it than we realize.
When Was the Last Time Your Stomach Actually Growled?
Remember being so hungry that your stomach made an announcement loud enough for someone sitting beside you to hear? Maybe it happened during a meeting, in a quiet classroom, or at some other wonderfully inconvenient moment when your digestive system decided it needed an audience.
We tend to associate that rumbling with hunger. And sometimes hunger is exactly what we’re experiencing. But those sounds, called “borborygmi,” come from gas and fluid moving through the digestive tract as its muscles contract. They can happen when we’re hungry, when we’re digesting food, or even when we don’t feel particularly hungry at all.
And let’s not confuse those empty-stomach growls with the gurgling, churning, and occasional digestive commentary that can happen after we’ve eaten too much. Those noises can occur while the stomach and intestines are busy processing food, moving gas and liquids along. In other words, a noisy belly doesn’t automatically mean the MMC is at work. Our digestive systems are capable of making themselves heard under all sorts of circumstances.
Some of those rumblings during fasting can be associated with MMC activity. So the noise isn’t necessarily an emergency announcement demanding immediate food. Your digestive tract might simply be doing what digestive tracts do. Who knew?
What interests me is how many of us rarely experience that sensation anymore. If we’re eating breakfast, snacking midmorning, eating lunch, grabbing something in the afternoon, having dinner, and snacking again before bed, when do we actually get hungry? Not bored, not tempted, not interested in something delicious, but physically hungry?
Of course, hunger doesn’t always announce itself with a growl, and a silent stomach doesn’t mean we’re eating too frequently. But the question is worth asking, especially if we’ve become accustomed to responding to every opportunity to eat rather than recognizing what our bodies are telling us.
As I’m writing this, I’m 19 hours into a fast, and my stomach just gave me a good, unmistakable growl. Normally, when that happens, I drink a glass of water and carry on. Since learning about the MMC, I’ve been curious about whether drinking water affects this digestive process. Turns out, plain water generally doesn’t interrupt the MMC the way eating does, although it can temporarily influence stomach contractions and movement.
What About Bloating, Gut Bacteria, and SIBO?
Let’s talk about bloating. That delightful experience when your pants fit perfectly in the morning, but by late afternoon, you’re considering whether unbuttoning them in public is socially acceptable. We’ve probably all had an encounter with an unhappy digestive system, but there’s more happening in our intestines than an occasional disagreement with lunch.
Our small intestine naturally contains bacteria, but generally far fewer than our colon. The MMC helps move leftover food particles, digestive secretions, and bacteria farther along the digestive tract. Think of it as helping keep traffic moving in the right direction instead of letting everything pile up and create a digestive traffic jam. And let’s face it, nobody wants a traffic jam in their intestines.
When that movement becomes impaired, bacteria can accumulate in excessive numbers in the small intestine, potentially contributing to small intestinal bacterial overgrowth, or SIBO. Symptoms can include bloating, gas, abdominal discomfort, diarrhea, and sometimes constipation. Impaired intestinal motility is one recognized contributor, although SIBO has several possible causes.
Now, here’s something worth considering. Our bodies, our health, and the way we respond to different lifestyle changes can be as individual as we are. What works beautifully for one person might do absolutely nothing for another. But if you’re accustomed to snacking throughout the day and don’t have a medical or nutritional reason to eat more frequently, why not experiment with giving your digestive system more time between meals for a few days and see how you feel?
Pay attention to any changes in bloating, gas, or digestive comfort. You might discover that a simple adjustment makes a difference, and wouldn’t that be a welcome surprise? No expensive supplements or complicated routines, just a little change in timing. Of course, persistent digestive symptoms deserve further investigation, and changing meal timing isn’t an established treatment for SIBO.
So, Should We Stop Snacking?
Not necessarily. But understanding the MMC gives us another reason to consider how frequently we’re eating and whether we’re allowing our digestive systems time to return to their fasting-related activity. Some digestive health experts suggest leaving approximately four hours between meals without snacking. It’s not a magic number, and researchers haven’t established one ideal interval for everyone. The size and composition of a meal can affect how long the digestive tract remains in its fed state, so four hours is a practical guideline to experiment with rather than a guarantee that the MMC will complete a particular number of cycles.
And this is what makes the discovery so interesting to me. I’ve spent years paying attention to what I eat, how I prepare my food, and how my body responds to different ingredients. Now I’m learning that the time between meals deserves some attention, too. It’s another piece of information I can use to make more informed choices, without turning my eating schedule into a rigid set of rules.
The Autophagy Connection
Autophagy and the MMC have something fascinating in common: both are associated with periods when we’re not eating, but they have very different jobs. Autophagy happens inside our cells, where damaged or unnecessary components are broken down and recycled, and fasting can influence that process. The MMC operates in our stomach and small intestine, helping move leftover material through the digestive tract between meals. Two different processes, two different jobs, and another reminder of how much is happening inside our bodies when we’re not eating. To learn more about autophagy, read my article Autophagy: The Built-In Repair System That Makes Fasting So Powerful.
Apparently, My Digestive System Still Has a Few Surprises
I’ve spent years learning about nutrition, hormones, the microbiome, fasting, and how my body responds to food. I’ve changed what I eat, when I eat, and how I think about eating. Fasting became an important part of my lifestyle, and learning about autophagy gave me a deeper appreciation for what happens inside my cells during periods without food. Now I’ve discovered the MMC, another fascinating process that operates when we’re not eating. And I find that exciting because it adds something new to what I already understand about fasting and my body.
That’s one of the central messages of The Awakened Body. Listening to our body matters, but so does learning enough about them to understand what we’re hearing. Sometimes that means recognizing a familiar signal, questioning an old habit, or discovering an entire biological process we never knew existed.