Does this situation sound familiar to you? You open your pantry and see your favorite bag of chips and cookies staring back at you, and you tell yourself: “I’ll only have a small handful before putting it back.” Then, one small handful turn into several, and the small handful you had envisioned turns into an empty bag? Maybe, if you’re like me, it might be the freezer you turn to, and you’ll grab some cookie dough ice-cream instead. Whatever your favorite guilty eating pleasure is, if you can do the former and indulge with one bite or spoonful kudos to you, but for more people, this event is next to impossible. Why? Simply stated, you eat what your brain tells you to eat.

Why is this? North Americans are more educated than ever before to healthy food options to eat, but as a society, people are consuming an excess of 425 more calories per day than we did in the 1980’s. We have fitness pros, mental health advocates, government programs, dieticians, nutritionists, doctors in private practices, and on TV explaining the ills of overeating, and what it does to the body, but for many, it is information, and not acted upon.

Is it because people are lazy? Not, smart? Don’t care? Perhaps, these elements are at play for some, but it would be a massive overreach to pit overeating on just a lack of willpower by the individual. Rather, we have to look at the brain, and the physiological layers involved when it comes to overeating. So why do we eat?

Two reasons:

Maintain homeostasis: Consuming food to get the energy our body needs in order to keep us alive.

For pleasure: To manage our emotions, positively and negatively. Simple, but relatable examples would be eating at a 5-star restaurant with your spouse, or devouring chips in your pantry after a long day at work.

Socially speaking, how and why we decide to eat rests on these factors:

1. Social cues & learned behavior
2. Environment

Scientifically speaking, how and why we decide to eat rests on these factors:

1. Genetics
2. Circadian rhythm (body clock)
3. Hormones

Now, how we judge our “satiety” (feeling of fullness in between meals), and “satiation” (perception of fullness when we’re eating) plays a role in how we eat, but what makes us eat is hormonal satiation, and gastric distension. These functions are most controlled through the vagus nerve. The vagus nerve runs from our head and extends to way the abdomen. Both brain and gut have billions of neurons that send signals to one another through the vagus nerve. In addition to the vagus nerve, gut microbes are known to influence the Blood Brain Barrier (BBB) through the production of short-chain fatty acids (SCFA). These gut microbes create SCFAs to digest the fiber we eat, but also speak to our brain via the BBB to reduce our appetite when we eat.

If you read the prior article, we know that the BBB is responsible for protecting our Central Nervous System (CNS), and that the CNS is responsible for maintaining our body and mind. When the BBB becomes damaged and inflamed from overeating, and overconsuming calories of minimal nutritional value; obesity and metabolic dysfunction in individuals becomes a forgone conclusion. This event only further emphasizes and underscores a healthy diet along with exercise. Given the amount of people that are overheavy and obese in today’s modern society, it becomes ever more imperative for individuals to understand what happens to their body hormonally to influence satiety and satiation.

Gastric Distension:

Disruptions in the gut-brain connection effect the vagus nerve in a negative fashion on how fast we eat. Simply stated, fast eaters tend to be overeaters. Consistent overeaters are usually heavy-set individuals. Why? When you overeat, the amount of stretching the stomach undergoes before the body communicates that were full often leads to overconsumption of food. On average, it takes around 20 minutes for the gut to speak to the brain and vice-versa that we’re full. When empty, the size of our stomach is about 50mL, and can reach more than 4000mL at its peak (4 liters or 1 gallon). This alone only further underscores the importance eating slowly and mindfully, even if today’s busy world sabotages you to do otherwise. Given this fact, adverse gastric distension, and delayed gastric emptying which occurs from overeating often can stymie one’s weight loss goals permanently if not brought under control. This is supplemented by current research done in animal trials indicating that the vagus nerve’s gut-brain communication is hindered through stress, eventually resulting in gastrointestinal problems. The damage from not being able to understand gastric distension in its entirety, indirectly permits overeating, and all the gastrointestinal and digestive problems that come with it as a form of learned behavior in human beings.

Hormonal Satiation:

While eating, the Gastrointestinal (GI) Tract, and other digestive organs such as the pancreas, and gallbladder tell us that food is coming in. These organs work with our hormones by communicating to the vagus nerve, and our brain to tell us how full we are when we eat. These hormones are:

• Cholecystokinin (CCK): The vagus nerve activates CCK which is responsible for stimulating the digestion of fat and protein, telling us when were done eating.
• GLP-1, and Amylin: GLP-1 creates and releases insulin. It also slows down the rate at which food moves from the stomach to the small intestine. Amylin works similarly, but instead reduces our food intake when we eat.
• Insulin: Acts as a communicative hormone to the brain that tells us to stop eating. Insulin is released by the pancreas when we eat carbohydrates and protein.

The hunger hormone ghrelin communicates to the gut to increase your appetite and eat more food. From there it effects your sleep wake cycles, and primal cues for food. Now that we know how the body utilizes, and assimilates the food we eat, the dialogue of what we eat becomes ever more important. How we make those decisions’ day after day will dictate to our brain what needs to be done so as to maintain our long-term energy, and nutrient needs. This process is governed by the leptin feedback loop.

Leptin Feedback Loop:

Leptin is a hormone that is released by our body fat. Via the BBB, leptin communicates to the brain to let us know how much energy we have stored vs what we consumed, and insulin concentrations in the blood. In layman’s terms, high leptin levels tell your brain you’re hungry, and low leptin levels speak to the brain telling you that you’re full. This feedback loop occurs 24/7 in your body. As a consequence, it influences our energy expenditure (how much we move), food intake, appetite, and nutrient absorption. When the leptin feedback loop works properly our bodyfat percentage, the rate which we metabolize food, and our hunger levels stay optimal. However, when it’s not, our metabolic rate slows, and we become leptin resistant. This event can place the endocrine system, in particular the thyroid, and hypothalamus in flux. When our thyroid function diminishes due to factors outside the natural consequences of aging, but by eating and drinking junk, our body, and brain will tell us to move less and eat less, which lowers the amount of physical activity we do. When we couple a sedentary lifestyle along with eating same foods we did in our youth into adulthood and at the same quantities, is when we begin to get into trouble.

Our leptin feedback loop can make adjustments for us without gaining weight, but that doesn’t mean that the leptin feedback loop can always beat hyper-rewarding, heavily processed foods, however. Think of two fighters in the ring trying to beat each other up. If someone gets peppered all fight, or gets knockout early, they lose. In this case, the loser is your leptin feedback loop. See, when you eat nutrient poor foods that are chemically processed, stripped of its essential fatty acids, and fiber, not just sometimes, but continually, it slows the pace in which our body’s ability can go back to its happy homeostatic regulating self. In other words, once you gain a lot of weight, losing it becomes a lot more difficult. In essence we’re more likely to pick the chips, cookies and processed junk in the pantry first vs the kale, spinach and other greens in our fridge to eat, not just one time, but most of the time. So, when we try to eat healthy or eat less, our body revolts. At least initially. When this is done on a consistent basis our body’s natural watchdogs, being our leptin feedback loop gets injured and inflamed, leading to hypothalamic inflammations.

Hypothalamic Inflammation, and Hyper-Palatability

Most feeding of foods that are nutrient poor and highly caloric disrupts the gut-brain pathway, killing healthy gut bacteria leading to hypothalamic inflammation and leptin resistance. Insulin & leptin resistance work in similar ways. Insulin resistance prevents the body from regulating blood sugar levels which for some results in being diabetic or having liver and heart disease. When we’re insulin resistant our body can keep making more insulin to keep our blood sugar under control somewhat.

Ignoring the leptin signals that indicate fullness, however, means that we’re making the decision to eat and then eat, and then eat some more. Leptin resistance, and hypothalamic inflammation work in similar fashion. We produce leptin from our body fat in order to maintain leptin levels, so when hypothalamic inflammation takes place as a result of poor eating, we continue to produce leptin, but we also get fatter too. Then, because our brain is inflamed the body wants to keep eating more despite the health consequences. It can happen due to genetic and environmental factors, but the brain will view this excessive weight gain as a new normal in some individuals, making it even harder to lose weight. For some, losing weight seems next to impossible. Regular portion sizes no longer make our body feel happy and nourished, and that we want to eat the world. Do you find yourself consuming these foods on a consistent basis in heavy quantities, are overweight/obese, not active consistently, coupled with a limited desire to be active?

• Pizza
• Alcohol
• Donuts
• Desserts, cookies, pie, granola bars, bread
• Soda, energy drinks, sports drinks.
• Fried foods

If you fall into this category it sure sounds like s*** hit the fan, doesn’t it?

Do you want to stop this cycle? Be healthier? Feel better?

You can turn the boat around, but you must decide to do it. Stay tuned to next week’s article:

“How to Stop Overeating for Good”. I will discuss the mental and practical components of overeating. I will be examining topics that other people don’t want to talk about. No fluff.

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