Metabolism Explained

May 16, 2022  -  Nutrition & Wellness

When you hear the word metabolism what do you think of? In diet culture today, metabolism has become a trigger word and one that is thought to be the holy grail if you will when it comes to weight loss. When you see weight loss and diet products on the market today, you will notice words and phrases such as “speed up your metabolism,” “reset your metabolism,” “boost your metabolism,” and other phrases like that. But do these products actually have an effect on our metabolism? In order to make that determination, we first must understand what metabolism is and how it functions.

While it is true that metabolism is linked to weight management to a certain extent, contrary to popular belief, a slow metabolism is rarely the cause of weight gain. For starters, metabolism is a natural process. Metabolism is essentially the process by which your body converts food and beverages into energy. What this means is that the calories consumed from what you eat, and drink are combined with oxygen to release the necessary energy your body needs to function properly. When it comes to your metabolism there is Resting Metabolic Rate and Basal Metabolic Rate. For the purpose of this course and discussion, we are going to just hit on Basal Metabolic Rate which will be referred to as BMR going forward. BMR is the total number of calories (or energy) your body needs to perform basic, life-sustaining functions such as breathing, heartbeat, circulation, nutrient processing and so on and so forth. With that being said, there are a number of factors that determine an individual’s base metabolism, some of which comes down to genetics, what you are born with. Those factors are:

Your body size and composition

Individuals who are larger either from weight or muscle naturally burn more calories, even while at rest.

Your gender

It shouldn’t come as a surprise to find out that men usually have less body fat and more muscle than women. This essentially means that men tend to burn more calories than women do because muscle tissue is metabolically more active and therefore burns more calories than fat tissue alone. So, the saying is true that men tend to have an easier time losing weight than women do.

Your age

As you age, you naturally lose muscle which now allows fat tissue to account for more of your weight, so the rate at which you burn calories also decreases. All this to say, the older you get the harder it is to lose weight and the easier it is to gain weight. Joys of aging!

As you can see, there is very little you can do to really change our BMR or metabolism. Meaning, the energy needs of our body’s basic functions aren’t easily changed. Outside of BMR, there are 2 other factors that determine calories burned that I am going to touch on super quick because I think all of this is important to understand on a basic level to put weight management in perspective.

Those 2 factors are:

Thermic Effect of Food or food processing

This is the energy used to eat, digest and metabolize food. Meaning calories burned through the digestion process. About 10% of the calories from proteins and carbohydrates you consume are used during the digestion and absorption of food and nutrients. It is important to note that out of the macronutrients, proteins, carbs, and fats, proteins have the highest thermic effect. Proteins take the longest to digest and absorb, so your body uses more energy digesting protein and that my friends is why I say protein keeps you fuller longer!

Physical Activity

Well, this is self-explanatory. Physical activity in this context is intentional physical activity such as biking, running, playing tennis, weightlifting, etc. Outside of your BMR and thermic effect of food, physical activity rounds out the calories burned throughout the day. It shouldn’t be a surprise to know that physical activity is the most variable of all the factors that determine the calories burned each day. The bottom line here is the more active you are the more calories you burn.

I hope you realize by now that, while it may be tempting to blame your metabolism for weight gain, there are so many more factors involved when it comes to weight management. Only in rare instances is it ok to blame metabolism for weight gain such as certain genetic disorders such as hypothyroidism for example. Our bodies have many well-oiled and well-functioning mechanisms in place that regulate our body’s energy needs. Unfortunately, weight management is a complicated process. It is essentially a combination of all the things mentioned here: genetic makeup, hormonal control, overall diet, and your lifestyle to include physical activity level, sleep quality, stress management, etc.

With all of that said, let’s dig into 3 of the most popular myths as it relates to your metabolism and weight gain.

Myth #1: Eating six small meals a day can boost your metabolism

MYTH: This idea of eating smaller, more frequent meals is a thing I hear time and time again. There is no evidence to suggest that eating six small meals a day burns more calories and boosts your metabolism. What you are eating, and your portion sizes is most important. You can get the same benefit from eating 3 or 4 meals a day as long as you are in a caloric deficit. The bottom line here is that eating 3 meals totaling 1200 calories will cause the same thermic effect or calorie burn as consuming 6 meals totaling 1200 calories. It comes down to the total number of calories consumed accounts for the energy expended during the digestion process. So, as you can see, it makes no difference how many times a day you are eating.

Myth #2: Eating after 7pm will cause you to gain weight

MYTH: When it comes to your metabolism, it really doesn’t matter one way or the other when you eat. Most people, however, feel better eating the majority of their calories during the day when most active. Other people may choose to have a small snack before going to bed because you are either hungry or typically wake up the next morning hungry. If that is the case, I suggest eating fast digesting carbs such as a banana, orange, or cherries. Pro tip, these same foods I just mentioned also contain a good amount of melatonin which will help you fall asleep a bit easier at the same time as keeping you well satiated. Also try a slow-digesting food such as protein that will not only leave you satiated, but fuller for longer and chances are, you won’t wake up hungry! The last thing I will note here is that the trap most people find themselves in is people tend to make poor decisions late at night. Our hormones tend to shift throughout the day and especially at night. This may cause increased cravings and overeating, and this is where the bad decisions come into play and quite possibly where this myth was derived. So, it isn’t the time of day you are consuming your calories, it is the quality and quantity of those calories consumed.

Myth #3: “I’m not losing weight because I have a slow metabolism.”

MYTH: I briefly touched on this very topic earlier. Although it is true that metabolism influences your body’s basic energy needs and can be linked to weight to a degree, a slow metabolism is rarely the culprit to weight gain. It still comes down to how much you are eating and drinking and of course your daily activity levels. There can be, however, other factors that affect weight management such as hormones, genetic makeup, sleep, stress, etc. Those are ultimately the factors that determine your weight. The key is to be in a caloric deficit and maintain healthy habits.

Unfortunately, there are no tricks or hacks when it comes to weight loss. There is also no one trick pony that will speed up your metabolism. As long as you are in a caloric deficit with healthy whole foods, you will see healthy and sustainable weight loss. To see real results, I recommend you maintain a healthy, well-balanced diet and an active lifestyle! Also, if you want to ensure you are in a calorie deficit and are eating good quality foods, I recommend keeping track of your food over the course of 2 weeks at the minimum to truly get a solid sense of what your overall diet looks like. From there, you can make small changes and continue to assess your progress every 2 weeks. Remember, this is a long game we are playing, so slow and steady is key!