![NYSC Undercover: Why Your Brain Loves Junk Food](https://www.elitefts.com/wp/wp-content/uploads/2013/09/NYSCUndercover.jpg)
elitefts™ Sunday Edition
America, land of the free…and obese. While prescription drug companies continue to scramble for the miracle weight loss pill (that diet and exercise stuff isn’t fun), obesity, diabetes, metabolic syndrome, and heart disease rates continue to escalate. While nutrition gurus continue to argue on Facebook about “high carb versus low carb,” “clean eating versus IIFYM,” and “fasting versus six meals,” everyone is missing the bigger point. Let’s start to examine appetite and satiety and why you eat so damn much to begin with.
You see these bodybuilders/fitness models? They’re all pretty lean and in shape, right? Maybe they have it figured out. But no. They diet and exercise and that’s hard. “I don’t like chicken,” “I hate protein shakes,” “I refuse to do cardio,” “Weights make me bulky,” or “I’m not going to restrict myself and be unhappy.” Yet these are the people who are unhappy with what they see in the mirror every single day. So why can some of us find a way to make the impossible task of dieting possible?
Staying in great shape comes down to willpower. End of story. No pill, super secret arm blasting routine, or elaborate nutrient timing plan will override that. At some point, you'll have to simply say no to certain things that you may really want. How you cope with this will determine how successful you’ll be. For the people who will want to chime in with, “I love my clean food; it’s all I want to eat anymore,” just shut up. Nobody drives by a Five Guys and doesn’t want a burger and fries. It’s in our nature and I’ll explain why.
Appetite is much more complex than people believe. From your senses (taste, smell, sight) to the cascade of hormonal fluctuations pre- and post-eating, eating is about much more than just chewing some food and swallowing it. Everything about your food matters—from macronutrient composition to the level of salt to the amount of crunch it provides. Taste is the main driver in the ingestion of food. We're full of taste receptors from the mouth to the gut that play a role in the complexity of our relationship with food. Our desire to eat is woven into our DNA, as the body requires the energy provided by food to perform all our bodily tasks to survive. Food regulation is centered on energy expenditure and the reward systems in our brain.
People seem confused as to why we are so prone to overeating, but from an evolutionary standpoint, it makes perfect sense. Your body has a host of processes that it runs all day and they require ample amounts of energy. So wouldn’t it make sense to always make sure that there is a fair amount of nutrient availability? It sure would, which is one reason why we store fat. It's a protective mechanism from stretches of famine that we once endured. Because famine was so common for humans, the brain got used to searching for high-energy foods.
To make sure that your body always gets the energy that it so selfishly wants, your brain is constantly sending and receiving messages about your energy level. Feed me! Feed me! Some of us can suppress or control these signals better than others. However, once you study the hormones associated with hunger, you’ll likely find that appetite stimulation is much more powerful than suppression. So before you even begin your diet, the cards are stacked against you.
I’ve found that people fall into one of two categories. Either they love food and fantasize about Cold Stone milkshakes all day (this is me) or they could really care less about food and may sometimes forget to eat. The latter type of person very rarely struggles with weight problems. He simply eats to survive and is more worried about other things. The former person has allowed food to have more control over his life similar to a drug. This is where it gets muddy.
I’m not here to argue whether or not food is a drug or if obesity is a “disease,” but a drug is simply something that has a physiological impact on the body when taken/ingested. Food induces numerous physiological changes, has implications in the brain, and can have plenty of side effects if abused (obesity, diabetes). And I’d venture to say that it has addictive properties as well, thus making for a pretty substantial drug. So while you may not view it as one, it certainly matches the description.
You versus junk food—a battle few win
Fast food restaurants and food companies spend a lot of time trying to figure out how to make their food more arousing, tasty, and addictive. The temperature of foods, how quickly they melt, the contrast they provide, the amount of salt/sugar, and the combination of high glycemic carbohydrates and fats all play a role in your brain's response to food. The goal, of course, is for you to crave these foods and be able to eat a lot of them.
Did you ever wonder why a greasy cheeseburger loaded with bacon and a side of crisp French fries tastes so damn good? It isn't your fault that you want it. Your brain is constantly reminding you how delicious these foods are. Unfortunately, your brain is pretty good at remembering such a pleasure-packed experience. Over time, food and your mood become closely intertwined because they share a common neural circuit. This is one reason why people “stress eat.”
There’s a portion of your brain (amygdala) that receives information on aspects of your food (taste, smell, texture). It takes this information and makes a memory of it so that you can “find” it or experience it again. Obviously, certain foods will do a better job at forming a memory. Your chicken breast and asparagus is forgettable, but the cheesecake you just ate is setting off all the happy lights in your brain.
The sense of well-being that you get from these foods is from a region in the brain referred to as the mesolimbic system. You may have heard this referred to as the brain's “reward center” because it works to process pleasure. This region is also responsible for influencing dopamine, which is a neurotransmitter that plays a role in emotional response, pleasure, desire, reward, movement, and more. Drugs like cocaine and methamphetamine work in part due to their role in altering dopamine levels, so they can have powerful effects on the brain.
In the study, “Mesolimbic dopaminergic system activity as a function of food reward: A microdialysis study,” researchers compared the dopamine levels of rats fed either highly palatable food or regular “low” palatable food. They found that when there wasn't any food available, there weren't any changes in the levels of dopamine in the body (1). However, when they ate the high palatable food, there was a significant rise in dopamine, much more than when the rats ate the low palatable food. Similar studies on humans have found that even the mere sight or smell of food can initiate your feeling of pleasure through dopamine release.
They concluded that the “mesolimbic dopaminergic system is activated on the ingestion of food and suggest that its activity is related to the rewarding properties of foods” (1). Some suggest that the more you indulge in highly palatable or tasty food, the more you will need to satisfy your craving for these types of foods. You may become accustomed to a certain amount of pleasure per day.
New research from my alma mater, the University at Buffalo, found that compared to lean mice, obese mice had fewer taste cells that responded to sweet stimuli and their response was much weaker. The obese mice then compensated by eating more than the lean mice. This is another reason to keep body fat levels in check.
In today’s day and age, we no longer worry about the availability of our food. We don’t eat what we need. We eat what we want. We have access to basically any sort of food. So is it any wonder that we become so attached to tasty foods, so much so that we refer to them as “comfort foods?” It’s our hedonistic response to such a delightful treat. Eating cake makes you happy and who doesn’t like being happy? So we eat more, and the more we eat, the worse we become at realizing when we're actually full. Pretty soon, you've set yourself up to have a ravenous appetite even though you're probably sedentary the majority of the day and have more than enough fat to live off.
In part two, I'll talk about some of the hormones associated with hunger, how to suppress your appetite, and more.
References
http://www.sciencedirect.com/science/article/pii/0091305795001875