There are both biological and physiological reasons why at various times throughout the day we feel “hungry.” We all need energy to survive, and finding that fuel is a drive that is innate in all living organisms. It is not surprising then that our body consists of complex systems that control our urges to eat, food intake, and digestion, all driven by hormones. But in the 21st century, all the constant stimulus can disrupt this, causing our bodies to send hunger cues much more often than we want or need.
So what can we do to stop it?
The Gastrointestinal (GI) Tract
The GI tract is muscular canal through our body whose main role is digestion, but it does so much more. We tend to think of digestion as starting in our stomach, but in reality it begins in our brain and is organized by our nervous system well before food ever reaches our mouth.
As our stomach empties, the release of the “hunger hormone,” ghrelin increases. Ghrelin is found in cells in our stomach which stimulates appetite and says it’s time to eat. This activates neurons in our hypothalamus that signal us to get up and get moving to find food. When we see or think about food, the brain informs the rest of our body to prepare for food. At each stage of digestion, the next part is told to expect food and nutrients to be coming soon. So, if food seems to be nearby, our brain messages our mouth to start salivating, our stomach to prepare by secreting digestive enzymes, and so on.
Once we find and eat some food, it takes time – about 15 minutes – for that to travel through the esophagus and into our stomach. In our stomach, there are stretch receptors that signal to our brain it is filling up, which is something that we can – and should – learn to tune into (more on this in a bit). While in the stomach, food is churned and mixed into a partially digested liquid known as chyme that can then be emptied into the small intestine for digestion and nutrient absorption. This happens slowly! It usually takes between one and four hours for our stomach to empty completely, depending on the foods we eat and how much of it. As the rest of the journey through our GI tract continues once the stomach has emptied, the cycle repeats with release of more ghrelin, and so on.
The entire process of digestion is controlled by our autonomic nervous system, which is outside of our conscious control. There are two branches of this: the sympathetic nervous system (SNS – our “fight or flight” system), and the parasympathetic nervous system (PNS – “rest, digest, and repair” system.) When the SNS is activated with intense movement, stimulation, or stress, digestion tends to shut down digestion and appetite. The reverse is usually true with PNS activation, which regulates digestion and movement through the GI tract.
Need vs. Want
If only it were that easy, right? The intricate weave of our body systems and hormones would do exactly what it is made to do: hormones are released when our stomach is low on energy, we eat just the right amount of quality foods full of adequate nutrients that fuel us to get stuff done, we function well, and live a full and active life. Unfortunately, it is often not that way.
Hunger and digestion can be affected by internal signals (what is happening inside our body), as well as what we see and smell externally. This affects our appetite, hunger, and fullness. In the world we live in today, there are almost always constant food cues and these ever present reminders can cause our appetite to get out of whack. The drive to eat comes not only when our body truly NEEDS energy, but also from a variety of cues in our environment. Eating is pleasurable, and often times people don’t eat because our bodies truly NEED the calories, they eat because something tastes good or we WANT to eat it.
This is why, after eating a filling meal, when we sit down on the couch to watch some TV, we all the sudden want to enjoy a big bowl of popcorn. Our PNS is activated, we are relaxed, and our minds are free to wander – many times to what is in the refrigerator. Do we truly need the energy the popcorn will provide, or do we just desire to have something to munch on while we relax? Luckily, unlike our distant ancestors, we don’t have to go out and hunt for all of our food sources. Today, we are constantly bombarded with signals telling us “it’s time to eat!” These cues can stimulate ghrelin to release and our GI tract to prepare for nutrients, even when we don’t need them. This is why, if you are used to eating a snack after dinner, your stomach will grumble signaling “give me food” but we don’t need it for survival or fuel. Our GI tract adapts to what it is used to processing, so if we normally eat at a certain time, it will prepare for that.
So how do break the chain? How can we tune into what our body truly needs for energy and cut out the rest? As it turns out, there are some relatively simple things we can do to eliminate the mindless eating and avoid all the excess calories.
Eat Slowly and Mindfully
This simple technique involves taking time to truly enjoy what we eat and being aware of what we are consuming. Instead of inhaling your meals standing at the counter while scrolling through social media, sit down at the table, turn off distractions, and pause between bites. This will help you recognize hunger and fullness cues, eat less while feeling more satisfied (remember those stretch receptors in our stomach? This will give them a chance to signal to our brain that things are filling up.), experience and enjoy the food we eat, and aid in digestion.
Consume Adequate Nutrients
Our stomach empties slowly, and the type of energy we consume depends on what and how much we have eaten. Here is what we know:
Carbohydrates empty first, then proteins. Fats and fiber move the slowest.
Liquids empty more quickly than solids.
Small particles empty more quickly that large particles.
What does this mean to you? Ideally our meals will consist of lots of lean proteins, high fiber foods, and more complex forms of carbs. The more complex the carbohydrate, the longer it takes to digest. If we want our stomachs to take longer to empty, we want to fill it with lots of good foods that will take more time to process. Fiber and lean protein truly helps us stay full longer.
Do I really NEED to eat this?
Above all, the goal is to eat quality whole foods, full of good sources of energy and nutrients. It is easy to fall into a pattern of quick and easy stimulus and response: “I feel hungry, I need to eat NOW.” But the next time you are on the couch and want to dig into that bag of potato chips, pause for a minute, and think: do I NEED this food for energy, or am I eating for pleasure?
It takes time and discipline, but you can change your habits. The more often you successfully break the chain, the less power it will have, and your body will learn the new pattern.
At Telos, our nutrition program meets you where you’re at and will help you develop healthy, sustainable habits. Click below to schedule your free intro to learn more.
Scott-Dixon, K.; Beradi, J.; Pierre, B.; Kollias, H.; DePutter, C. (2019). The Essentials of Nutrition and Coaching. Precision Nutrition Inc.
About the Author
Karen Hazelton is Precision Nutrition Level One Certified and a Healthy Steps Nutrition Coach. Her sports background is in tennis, and through hard work and dedication she earned a Division One tennis scholarship to University of Northern Colorado. An important component of her training was developing strength in the weight room. Being physically strong and having a good foundation of metabolic conditioning was essential to playing her best on the court. After earning a degree in mathematics, she moved back to her hometown of Tucson and became a high school math teacher.
Karen loved her work as a teacher, but after taking time out of the classroom to raise her two young kids, she realized how she missed coaching and working with athletes. That led her to obtain her training and nutrition certifications. She loves to see clients use fitness and nutrition to become stronger, happier, and healthier versions of themselves.