We all know that we must eat to live. Food gives us energy, helps to build and repair cells, and provides the nutrients our bodies require to operate correctly.
We, of course, also recognize that too much food can make us fat and too little food will make us starve. When someone is overweight, they are told to go on a diet and/or exercise more. Common sense, right? So why is obesity so rampant in this country and diets nearly always fail?
Calories In, Calories Out Equation
Nearly all my life I have believed that our bodies follow a simple equation:
Calories Consumed – Calories Expended = Calorie Deficit or Calorie Surplus or Zero
Calorie deficit = weight loss
Calorie surplus = weight gain
0 = weight maintenance
This makes things sound so simple and seems to make logical sense. However, if you have ever struggled with your weight or hit a “weight loss plateau” this simple equation probably makes you want to scream.
You see, we were created by God as incredibly elaborate and complicated creatures. Our bodies function through a very complex set of chemical reactions involving metabolic pathways, hormones, and other considerations. The way God made us is actually perfect. Our bodies have all sorts of control mechanisms and backup plans to help us maintain our weight at a healthy level.
You can see proof of this by the fact that you will never see an obese animal in the wild. Obese animals are only found when we humans control or manipulate their diets (sorry to my overweight dog). So why are so many people overweight and obese? Because we have derailed our bodies’ regulatory systems and backup plans by the way we eat and the things we eat. Just like with everything else in life, humans have messed up God’s original perfect design.
Fortunately, God has also given us the gift of scientists who are beginning to uncover how our bodies were designed to work. We can use this information to help us get back on track.
First of all, yes, excess food does cause excess weight gain. The equation is not entirely wrong. If you eat more than your body needs for fuel, you will gain weight. However, this only tells part of the story because all calories are not the same.
How Each Type of Food is Used By The Body
When we eat a meal, our body begins breaking down all the food we eat into components it can use for all of the complex processes that take place in our bodies all day long. Carbohydrates are typically broken down into glucose and used as the body’s main source of energy. Excess glucose is stored in the liver and muscles as glycogen, but when the storage areas fill up, the excess glucose is converted to body fat for later.
When we consume fats, our body breaks them down into fatty acids and uses them to synthesize our hormones, carry vitamins, develop our brains, cushion our joints, and reduce inflammation. Fatty acids can also be used for energy or converted to ketones to provide energy to our brains. Excess fat consumption can, of course, be stored by the body as, you guessed it, body fat.
Protein is broken down by the body into amino acids. Amino acids are the building blocks for our body. Protein is absolutely essential. After water, protein is the second most abundant molecule in the body, and our bodies cannot create protein on its own. Protein is used to build and repair muscle tissue and for DNA replication. Excess protein can be converted into energy (glucose) or stored for later use (stored either as glycogen or body fat), while some excess protein is excreted in our urine.
So, all of these types of food can eventually be converted into glucose which is used as energy for the body. As long as we are eating enough of any type of food our bodies are able to convert that food into energy. We also can see that too much of any kind of food can result in a surplus which the body will store as body fat.
How Different Types of Food Effect Satiety (Feeling Full)
God originally created our bodies with the amazing ability to maintain homeostasis – to stay the same. When you read the stories in the Bible or history in general, they aren’t constantly talking about counting calories or macros or planning out meals to make sure that everyone eats the right amount and the right types of food. Eating wasn’t supposed to be as complicated as our modern world has made it.
We have this amazing ability in which our brains tell us when we are hungry and our brain is also able to tell us when we are full and have had enough. The interesting thing is that different types of food send different signals to our brain about hunger and satiety.
Let’s compare eating a 6 oz cut of filet mignon to drinking a 32 oz Big Gulp Coke. The filet has 330 calories. The soda has 410 calories. Which one will make you feel more full? I hope you said, “the steak”, even though it has fewer calories and fewer ounces. Now, which one will give your body energy? Both, but in very different ways. Depending on how you cooked it, your steak has only protein and fat (meat does not have any naturally occurring carbohydrates). But your soda has all carbohydrates, with no fat or protein.
Your body can use the carbohydrates in your soda immediately for energy and it can convert the extra into glycogen for later energy needs. But if your glycogen stores are already full, that extra goes straight into fat storage. And your body is left without any of the crucial fats or proteins necessary to actually keep you alive and well. And your brain is smart enough to say, “hey, I’m still hungry, give me more food!” Not because you need more calories, but because you need more nutrition.
Your steak on the other hand, although it has fewer calories, is much more likely to give you feelings of satiety (although you may need more than just the steak to feel truly full, depending on what else you’ve eaten throughout your day). The steak is able to provide your body with the crucial protein and fat it needs to build and repair cells and keep your brain functioning well.
There are many factors related to satiety. And much of it still confuses many researchers, we don’t fully understand the complexities of how our bodies decide when we are full or not. But we have learned some important lessons. First of all, the type of food that tends to be most satiating is protein. If you are struggling with feeling hungry all the time, it is likely that you are not eating enough protein with your meals. In our culture, we tend to snack all the time, but we snack on chips, crackers, granola bars, and maybe a fruit or vegetable if we’re trying to be really healthy. But none of these things contain a whole lot of protein, so they often don’t last very long.
Complex carbohydrates are the next type of food that help us feel full. These are included in things like “whole grains” and fruits and (non-starchy) vegetables. A bowl of oatmeal will make you feel more satiated than a candy bar because the carbs are complex in the oatmeal and take longer for our body to break down.
What Role Do Hormones Play in Appetite and Satiety?
Our hormones play a huge role in how our body processes and uses the foods we eat. There are two hormones in particular that play a key role in our appetite, leptin, and ghrelin.
Ghrelin is known as our appetite stimulating hormone. Ghrelin is produced by our stomach when it is empty and sends a signal to the brain to go find food. Once we start eating, our ghrelin levels go back down. There are a couple of important things to know about ghrelin.
Ghrelin is linked to our stress response, as your stress levels rise, so does your ghrelin levels. This may be why people tend to eat more when they are stressed. Ghrelin is one of the main causes of “the munchies”. Managing our stress levels and getting adequate sleep tend to help keep our ghrelin levels in check.
Another important thing to know about ghrelin is that one of its primary goals is to maintain that homeostasis in the body. Which means that if you start restricting your calories, your ghrelin levels will increase. The longer you stick with your calorie decrease (your diet), the higher your ghrelin levels will be. This helps to explain why sticking with your diet gets harder the longer you do it. Your body wants to stay the same so it creates more and more ghrelin which makes you feel more and more hungry (it’s not just because you have weak willpower, your body really is “fighting” against your diet).
Leptin is our other appetite hormone and its goal is to avoid both starvation and overeating. Leptin is created by our body fat (adipose tissue). When we have high amounts of body fat we have hight amounts of leptin. The leptin tells our brain, we’ve got enough energy and fuel stored up, we’re not starving. If our body fat levels dip too low, the lack of leptin will signal to our body that we are starving and we need more food. When everything is working as it should, we are able to maintain our weight just where it needs to be thanks in large part to leptin.
So why do obese people still get so hungry if they have plentiful body fat and therefore high leptin levels? It seems that after a while, our brain stops receiving the leptin signals when they become chronically high. This is called leptin resistance, and the majority of overweight and obese people (especially women) are found to be leptin resistant. Since the brain is no longer “seeing” the leptin, it thinks we are actually starving and sends directions to our body to eat more and use less energy. Losing weight now requires a tremendous amount of willpower to fight off a brain that thinks it’s actually starving.
Leptin still creates a challenge for people who aren’t leptin resistant, but who are overweight. Successful dieting signals a leptin response. As our body weight begins to go down which creates more leptin which tells our body – eat more food. Again, your body wants to maintain homeostasis.
How Did We Get Here?
If our bodies were created so well and are so focused on keeping homeostasis how did so many people become fat in the first place? Our bodies were originally created in an environment of feast and famine. All throughout history, we can see evidence that at times food was plentiful, and at other times, food was scarce and hard to come by. Our bodies were created to work well in this type of environment. Storing excess fat in times of feast to be used during famines and signaling to our bodies to keep searching for food in times of famine, and just maintain when things are going well.
The problem is that we no longer have times of feast and famine and we no longer consume food based on our bodies’ signals. Everything in our modern world revolves around food and it is readily available, convenient, and addictively delicious. We eat all the time, whether we are hungry or not, and we always eat everything we are served so as not to offend anyone.
Young mothers are taught to get their babies on a feeding schedule immediately, ignoring the biological mechanisms of the baby’s own body. We have been told by food marketing companies that our bodies will go into “starvation mode” if we go more than two hours without eating (as if requiring our bodies to dip into its own stored energy reserves is a problem). And most of us were raised to be card carrying members of the clean your plate club.
What if we only ate when we were hungry? What if we didn’t consider hunger an emergency? What if we specifically chose and balanced our foods to provide our bodies with the nutrition it needs? What if we simply considered food to be fuel for our bodies? What if we actually listened to our bodies hunger cues? What if we served our children healthy foods and trusted them to decide how much or how little they wanted to eat? What if we stopped eating fake foods and empty calories and started to go back to the foods that God originally created for us to eat?
What Do We Do When We’ve Already Gone Too Far?
It’s fascinating to learn all of these details about how our bodies work, but it can be a little discouraging to realize that once we are overweight or obese our bodies are actually working against our efforts to lose the excess weight. Do we just have to struggle and muster up massive amounts of willpower to fight against our own bodies to have any hope of losing weight and keeping it off? I think it does take some willpower, but that’s fortunately not our only hope.
As we’ve seen repeatedly in my last post on dietary fats and today’s post, our bodies are incredibly complex and there are many important factors at play when it comes to how our bodies use the foods we eat. Today we learned about how each of the types of food we eat are broken down and used by the body. We also discussed which foods help us feel more satiated, and we learned about the role our “appetite hormones” play in regulating our desire to eat or not eat.
One important thing we haven’t yet discussed is metabolism and the rate at which our bodies use the energy we provide it. This also plays an important role in our body weight and overall health. There are many other key pieces of this puzzle that I hope to slowly cover in the weeks and months to come as I learn more.
Today, I think we can use a few key takeaways to help us begin to make better decisions and improve our overall health. We’ve seen that our bodies need all three main “types of food”, carbohydrates, fat, and protein to operate efficiently. And it’s important to make sure that each of these types of food are included in our diets, in their healthiest and most natural form. Any diet that severely restricts our fat and protein intake can be incredibly detrimental to our health since both protein and dietary fat are so vital for many of our body’s processes.
Selecting real and nutrient dense foods will provide us with the fuel we need and help our bodies send the right signals to our brains that we are full (remember the steak versus the soda). Much of this is common sense, but difficult to put into practice. This is where the willpower and making intentional decisions about our food comes into play. Most of the time, we know the right thing, but that cheesecake looks so delicious!
Overcoming our hormones fighting against us can be difficult. However, there are some things we can do to help our hormones work more effectively. As I mentioned above, managing our stress levels and getting adequate sleep can help control our ghrelin levels. Staying properly hydrated (with water, not soda!) is also important for managing our hunger cues.
Another key piece in “healing” our hormone function is physical activity. Exercise, especially high-intensity burst style activities seem to help lower our leptin levels and reverse leptin resistance. For burst training, your goal is to cycle “bursts” of high-intensity activities with periods of rest or lower levels of activity. For example, include several 30-second sprints in your walk around the block. This type of exercise has been shown to increase metabolism and overall weight loss as well.
One of the most important things I want to suggest is that we begin to listen to and trust our bodies. If your baby cries for food, feed your baby. If your child says they aren’t hungry at dinner time, don’t force them to clean their plate. If it happens to be lunch time and you are still feeling full from breakfast, find something else to do besides eat.
Stop believing the marketing lies that you have to eat every two hours to stay healthy. News flash! Jesus went 40 days without food. Starvation doesn’t happen in two hours or even two days. Hunger is not an emergency (for most people).
Again, there is so much more to say about this topic, but little by little we can begin to make better and more informed choices about what we eat, when we eat, and even why we eat.
Today’s Action Step
Begin to pay attention to your body and listen to what it is saying. Are you eating out of habit and tradition or due to hunger? How do the different foods you eat make you feel afterward? Consider keeping a food log, not to track the number of calories or other nutrients you are consuming, but to take notice of how your meals are affecting you. Track your mood, energy levels, satiety, and anything else you notice after your meals. Even if you are leptin resistant and your body is sending the “wrong” signals, there is still a lot you can learn by listening to your body.
Do You Know the Truth About Dietary Fats?
Leptin and Leptin Resistance: Everything You Need to Know
As I’ve mentioned I will be continuing to study and research good nutrition and what it takes to live a healthy life. As I learn I’ll be sharing the information here on the blog. If you want to make sure you don’t miss future posts, be sure to join the Working Mom’s Balance Email Club to get an email about future posts. You can also follow me on Facebook to stay connected.
This is fascinating, Tracy! Thank you for sharing!