Ep 66: Is Metabolism Real? What It Actually Means to Have a 'Fast' or 'Slow' Metabolism
If you’ve ever said, “I just have a slow metabolism,” or heard someone say, “They can eat anything—they must have a fast metabolism,” you’re not alone. But what does that actually mean?
While I was live on Twitch the other day, someone in chat asked me, “Is metabolism even real? Someone told me it’s a medical condition.” That question stuck with me—because there’s so much confusion around the topic. So let’s clear things up.
🔥 What Is Metabolism, Really?
Metabolism isn’t just one thing—it’s the sum of all the processes your body uses to convert food into energy. When people talk about having a “fast” or “slow” metabolism, they’re usually talking about how many calories their body burns each day.
This is made up of a few key components:
Basal Metabolic Rate (BMR): The calories your body burns at rest just to keep you alive—breathing, circulating blood, digesting, etc.
Thermic Effect of Food (TEF): The energy your body uses to digest and process food (protein takes more energy to break down than carbs or fat).
Activity Level: This includes intentional exercise and non-exercise activity like walking, fidgeting, and cleaning.
All of these come together to form your Total Daily Energy Expenditure (TDEE)—which is the number of calories your body burns in a day.
⚙️ What Affects Your Metabolism?
Your metabolic rate isn’t fixed—it can be influenced by:
Muscle Mass: Muscle burns more calories than fat, even at rest. The more lean mass you have, the more calories your body uses.
Age: Metabolism tends to slow slightly with age, mostly due to muscle loss and changes in hormone levels.
Genetics: Some people are naturally more efficient at burning calories.
Hormones & Health Conditions: Thyroid function, stress levels (cortisol), and other health factors can play a role.
Sleep & Stress: Poor sleep and chronic stress can negatively impact your metabolism over time.
Dieting History: Long-term undereating or crash diets can downregulate your metabolism as your body tries to conserve energy.
💪 Can You Speed Up Your Metabolism?
Here’s the good news: yes, you can support a higher metabolic rate. Here are some of my go-to tips:
Build Muscle: Strength training is one of the most effective ways to increase your resting metabolic rate.
Stay Active Throughout the Day: Walk, fidget, move around—non-exercise activity adds up.
Eat Enough Protein: It has a high thermic effect and supports muscle maintenance.
Don’t Chronically Undereat: Eating too little for too long can cause your metabolism to adapt and slow down.
Get Enough Sleep: Your metabolism works best when your body is well-rested.
Manage Stress: Chronic stress can lead to hormonal imbalances that affect metabolic health.
🚫 Metabolism Myths to Ignore
Let’s bust a few:
❌ “Eating late at night ruins your metabolism.” Not true—total daily intake matters more.
❌ “Fat burners and metabolism boosters are magic pills.” Most don’t work, and any small bump in calorie burn isn’t worth the side effects.
❌ “Some people just can’t lose weight because of a slow metabolism.” While it may be harder for some, lifestyle factors usually play a bigger role than metabolism alone.
🧠 Final Thoughts
Metabolism isn’t a fixed trait or a mysterious medical condition—it’s your body’s engine, and you can influence how efficiently it runs. You’re not broken if your weight loss is slow or if you don’t burn calories the same way someone else does.
The real secret to “speeding up” your metabolism? Build strength. Move often. Eat enough to fuel your body. And take care of your stress and sleep.
If you found this helpful, you might want to check out my fitness app where I provide structured training plans that help you build muscle and support a stronger, more efficient metabolism.
Links:
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Jayd (00:00):
Is having a fast metabolism a real thing? Someone just told me it's a health condition. Okay, so it is and it isn't. Okay. Often within the health space, within the fitness and wellness space, when we talk about metabolism, what we're talking about is it is a catchphrase for all of the little systems that your body has for turning the food that you eat into energy or into muscle metabolism is just kind of, it's a catchall phrase, right? But when we talk about it in fitness and health, what we're usually talking about is how much energy is your body burning? How efficiently is your body breaking down the food that you eat and turning it into gains? And having a fast metabolism is something that we usually say when we mean that your body burns a lot of calories, you burn a lot of calories doing day-to-day things, and you burn a lot of calories in your workouts, and that's a good thing if you're trying to burn fat, right?
(01:09)
Hey there. Welcome to Coaching Corner podcast. I'm Jayd Harrison, AKA Jaydigains. I've been a personal trainer for about 10 years, and I've created this podcast to share with you some of the tips that I share with my personal training clients to help them to burn fat, get strong and eat better. In today's episode, I'm going to share with you a conversation that I had with my Twitch chat when I went live on my Twitch channel recently, that's Twitch.tv/Jaydigains. While I was doing one of my workout streams, one of my chatters asked me whether metabolism was a real thing or not. And so in today's episode, I'm going to talk all about what we mean when we talk about having a fast or slow metabolism, and I'm going to give you some tips and tricks for how to speed up your metabolism, AKA, get your body burning more calories.
(02:00)
So if you're interested in burning fat, this is a really great episode to listen to. It will help you to make sense of and sift through the types of information that you probably will see on social media regarding metabolism. Now, real quick, before we head into the episode, make sure that you check out my training app, which I recently launched to share some of the training programs that I read my clients through. You can find the link for that in the show notes or in the description below this video. Right now, I have a variety of programs up on the app that you can choose from, whether you're trying to work out at home or go to the gym, lift weights, burn fats, or increase your cardiovascular lower wellness, check that out. Go to my website, gd gaines.com or Jaydharrisonfitness.com. Without further ado, let's get into the episode.
(02:50)
In general, the more calories that your body burns, the faster your metabolism is and the fewer calories that your body burns the slower your metabolism is. But it's not really a scientific term, it's just kind of a way that we talk about your body's calorie burning. Now, there are things that can impact your body's calorie burning. For instance, if you have a thyroid issue, if you have a thyroid disease, that means that your body doesn't as effectively release the hormones that tell your body to do functions that burn a lot of calories. Your body's less efficient at running the systems that would use a lot of energy. Or on the other hand, sometimes if you have a different type of thyroid issue is that you have too much of different hormones where your body is burning way too many calories on things that it shouldn't be using as much energy for.
(03:50)
So in that way, that is a health condition that can impact your metabolism, that having thyroid issues can impact how effectively your body is using energy and running systems. There are things that you can do if you suspect that your body is not able to burn as many calories as you want it to if you're specifically trying to burn fat. First of all, the best way to speed up your metabolism, IE get your body burning more calories, get your body doing more stuff that needs to burn. Energy is to get moving. The more that you move, the more calories you burn. Every system that your body runs requires energy to spend and it's calories are like your fuel. You need fuel in your car for your car to run. Your body burns fuel, the food that you eat or the fat stores that you have as battery packs.
(04:44)
When you get up and you move around, the more active your lifestyle is in general, the faster your metabolism is, meaning you burn more calories, you use more energy. So building a habit of getting moving on most days for 10 to 30 minutes every single day is a great way to speed up your metabolism. IE burn more calories. And then another really important way to burn more calories and speed up your metabolism is to build muscle. Do workouts that are focused on challenging your muscles and getting you stronger because one building muscle is kind of a calorie expensive system like that system that your body runs, muscle protein, synthesis, healing, damaged tissue. These are really calorie expensive energy systems. So when you build muscle, you burn a lot of calories. Also, the more muscle you have, the more energy your body burns on a day-to-day basis just to power that those muscles to get energy to them so that they can push, pull, run, jump, climb, all those things that you want to do in your activity.
(05:55)
So building muscle is another great way for you to speed up your metabolism. IE get your body burning more calories. Another thing that you can do is sleep. A lot of people don't realize how much of an impact not sleeping well has on your body's efficiency and ability to manage its energy. If you haven't slept well, you're going to have a harder time getting up and moving because you're going to feel tired, right? So you're not going to burn as much energy and if you don't sleep well, that's your rest and digest. When you're sleeping, that's when your body runs repairs on your damaged tissues. So if you don't sleep a whole lot, then your body isn't able to effectively heal you from your workouts. So you risk getting sick. The more that your immune system gets suppressed, you're not going to be able to burn as many calories.
(06:45)
So sleeping as much as your body needs and how much you need to sleep is individual to you. A good general recommendation that a lot of people give is eight to 10 hours per night, but you may need more, you may need less. Women tend to need more sleep than men do, and we tend to need more sleep at different points of our 28 day hormonal cycle. So when you are in that period between ovulation and starting your period when you're PMSing, you might need more sleep and you might need more sleep when you are actually on your period than off. So listen to your body, give your body as much rest as it needs. Your body will tell you if you're not getting enough sleep, generally speaking, we all kind of know when we're not getting enough sleep, but signs that you can look for are you're feeling fatigued and tired all the time.
(07:28)
You're experiencing some mental health issues. You're feeling irritable, you have very little energy, you have trouble focusing at work, and you might catch yourself just wanting to nap all the time. These are good signs that you're probably not getting enough sleep or enough good sleep. Now some people can't help it that they're not good sleepers. Some people have sleep apnea, which is when your body just stops breathing while you're sleeping. Very, very common. And it's not just old people. It happens to a lot of people. I think I know somebody who's really baby 24, 23 who sleeps with a CP pap machine because he has sleep apnea. That might be something you need to look into if you have trouble sleeping. There's a lot of studies right now that are being done on how to help people improve sleep. You can participate in a sleep study, you can and also go to the doctor.
(08:21)
There's things that you can do. If you are woman and you're going through perimenopause, it's likely that you have trouble sleeping because that's just what our bodies do. We have a hard time sleeping when we're going through perimenopause, and so I encourage you to talk to your doctor if you have trouble sleeping because to bring it back to the topic at hand when you're not sleeping well, then that is going to slow down your metabolism, meaning you're just not going to be able to spend as much energy of your body because you're not recovering. And then the types of foods that you can eat to get your body to burn more calories are the types of foods that make your digestive system have to work harder. You have to run more systems to digest this food that's going to boost your metabolism by getting your body to burn more calories.
(09:07)
That's called the thermic effect of food. Yeah, so the thermic effect of food is that when every system that your body runs requires energy to run, and when you are digesting food that takes more steps for you to digest it, then your body burns more calories digesting it. So I suggest eating foods that are higher in protein, right? A high protein diet is generally recommended for fitness and fat loss, eating food that has lots of fiber in it. Soluble fiber is really great for helping to reduce belly fat, but it's also good for your tummy to feel good and digest them. But just make sure that you increase your fiber intake gradually so that you can avoid tummy trouble. So lots of whole grains, fruits and vegetables follow the healthy plate model. That's why it's here. This is a good solid visual reminder of how you should eat.
(09:54)
And if you eat this way most of your meals, then you will be giving your body sufficient metabolism boosting to get that thermic effect of food because your body's going to be having to break down complex carbohydrates. It takes more steps to break down protein, healthy fats as well. So if you're doing all of those things, exercising, eating according to the healthy plate model, sleeping enough and you're still having trouble burning calories, you need to figure out exactly how many calories you're eating every day. If you make all those changes and nothing's moving, then that's where you need to start getting a little bit more specific and specialized in your approach, right? So I don't actually recommend tracking for everybody. Tracking your food is really tedious, and especially for neurodivergent folks, it can be really overwhelming. But if you've done all of those other simple things and you have those checked off, then you're probably going to have to really get scientific about it.
(10:50)
So prepare yourself mentally to track what you eat and see exactly how your body responds on X amount of calories and be scientific about it. Aim for eating a specific amount of calories every day. See how your body weight responds. Check your belly circumference gradually reduce your calories within reason a hundred to hundred 50 calories at a time for a week. At least See how your body responds. And if you are starting to lose weight and you're starting to see inches go down after you've reduced your calories a hundred to 250 calories below what you were eating before, then your metabolism is fine. You don't have a slow metabolism, you just were eating too many calories right now. If you find that you're eating a super low number of calories and you're still not, your weight's not going anywhere, then that is a sign that you have a slow metabolism, meaning your body is just not burning the energy that it should be burning.
(11:46)
And in that case, you do want to make sure that you go to the doctor to check your thyroid and check if there's any other kind of health issues because there are some health issues that can cause your body to burn fewer calories and which makes it harder to lose weight or burn fat. But you can also ask yourself some questions because there are some things that will cause your body to slow down. IE burn fewer calories. One is being in a super low calorie intake for an extended period of time. If you've been eating a really low number of calories, your body will adapt to that because your body is built for the wild and in the wild. If you go through a really big stretch of time where you're not able to find the amount of food that your body ideally needs, your body will make its energy expense more efficient and slow down systems meaning spending less energy on things so that you don't starve, right?
(12:50)
That's why that system exists. And so if you have been eating a super low amount of calories for a really long time and you haven't seen any movement, well then that might be a sign that you don't actually need to go into a calorie deficit. Do you need to do a reverse diet? You need to get your calorie intake up before you start worrying about burning fat. You need to get those calories up. You are eating too little. There is such a thing as not eating enough food to burn fat. You need to have your baseline level of calorie intake. Pretty reasonable. Your maintenance level of calories needs to be healthy before you consider dropping calories to burn fat. So if you have been super low for a really long time, you need to start gradually increasing your calories as long as you have an underlying health condition ruled out, okay, still see the doctor, get blood work taken, rule out a medical thing, but reverse dieting that just involves over time in a slow and controlled fashion, increasing your calorie intake 50 to 150 calories at a time and eating that for a week to two weeks or maybe even longer.
(14:01)
And yes, you will see your weight go up probably slightly when you increase your calories because you've been really fucking low for a long time and your body's like, oh, hell yeah. Now we've got some energy. Let's quickly store that away because we don't know when this bitch is going to give us more food. You see what I mean? So you kind of have to mentally prepare yourself. Reverse diet is hard for a lot of people mental health wise, but that's what you have to do if you want to be healthy. So you increase your calories, your weight will likely spike up, but then it should come back down and then level out. Once it has leveled out, that's when you add more calories, another 50 to 100 calories, and then it'll be the same thing again. Your weight will probably go up and then come down and then stabilize.
(14:49)
And you keep repeating process until you reach the point where you're eating a pretty reasonable amount of calories for someone of your size. So you can calculate how many calories should a person of my size, my activity levels. You can find out what a good sort of reasonable amount of calories is for you to maintain your body weight. Once you have gotten to the weight where you're able to eat that amount without gaining weight, then you can cut calories, then you can go on a diet. Now, what will often happen, what happens with a lot of my clients when I have them reverse diet, if they have been eating a really low number of calories for a long time, once I get them to start eating more food, a lot of times they start losing weight. A lot of times people will skip the spike, come back down and plateau.
(15:37)
Some people completely skip that. That might happen for you. So that might be what you need to do. And another thing that can slow down your metabolism. I eat get your body to burn. Fewer calories is going on and off crash diets. So you might have this binge restrict pattern where you really don't like your body. You see something promoted on Instagram, this juice cleanse or whatever. You go on the juice cleanse, you're eating maybe a thousand calories a day, or maybe you're drinking a thousand calories a day. By the way, 1000 calories is the starvation threshold, okay? If you're eating 1000 calories or below, that is unhealthy. But some people will go on these crashed diets. Well, they'll eat that super low amount or they'll drink nothing but juice to have that really low amount of calories, and they'll get the illusion of having burned fat because their body will be dehydrated and they will not have the bulk of the food.
(16:38)
And they'll think, oh, I lost weight that was successful. They go off of this crash diet because they're fucking starving. And then they'll Kirby mode, right? They go off the diet and then they Kirby mode, just everything in sight, and then they end up gaining more weight because they binge the fuck out of the end of their diet. And then they start eating more and more and more calories than their body is ready for and can absorb and use. So that binge Kirby mode slash restrict crash diet, if you tend to alternate between those where you have periods where you're just like Kirby mode eating everything, and then you're like, oh, I'm going to starve myself for a short period of time, that also can get your body into a place where it's not really burning a lot of calories because your body, again, built for the wild, is reading your behavior as a sign of an inconsistent environment.
(17:32)
So it's like we don't know when it's going to be the next place that we go into where we don't have any food at all. So we need to store away whatever extra energy we get whenever we do the binge part. You see what I mean? If you have that binge restrict kind of cycle, that also is going to reduce your calorie expenditure. IE slow down your metabolism. And again, if that's the case for you, you likely have a very low number of calories that your body can stand to eat without gaining weight. And again, the solution to that is getting on a consistent diet, right? Getting to where you're eating a consistent amount of calories every day, and then see how your body responds to eating that consistent amount of calories over the course of at least a week. And then see where it is and make a decision from there about whether you need to reverse diet, bring your calories up, or if you are ready to reduce your calories, but you kind of have to have those first things in place that I talked about before.
(18:28)
Exercising enough, eating according to the healthy plate model, sleeping enough. Those are the bare minimum things. If you're not doing that, you need to take care of that first. And then if that doesn't work, then you get more specific about how many calories am I eating? Figure that out. Figure out how many calories your body is used to having, and figure out how your body responds to having a consistent amount of calories that you take in every day. And then once you have that data, you can make a decision, but still going to the doctor and making sure that you don't have an underlying thyroid issue or a Crohn's disease or something is also good data to have. So I hope that that answers your question. What we mean by slow metabolism, fast metabolism, what it means in terms of fitness and how it can be related to a medical issue. More often than not, in my experience, it's related to having an inconsistent relationship with food and just not being super mindful of how you eat and how you exercise. That's most people's case. But thyroid issues are really common too. So check with your doctor, but also make sure that you kind of check off the list for those things.
(19:38)
Thank you so much for watching or listening to this episode of The Coaching Corner podcast. Again, I'm Jayd Harrison, AKA, Jaydigains. If you haven't yet, make sure that you like this video and subscribe to my channel if you're watching on YouTube. If you are listening to the podcast, thank you so much. Make sure that you follow the show so you always get the latest episodes delivered right to your device. And again, make sure that you check out my training app, which is linked in the show notes or the description below this video. I will see you in the next episode. In the meantime, make sure that you eat your veggies, eat your protein, drink your water, and prioritize your self-care. I'll see you soon.
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