Welcome to my science based guide to speeding up weight loss with thermogenesis.
Read this guide all the way through and you'll find out exactly what thermogenesis is, how it burns calories, and how you can use it for bigger and faster weight loss results.
Most importantly, you'll learn many different ways of boosting this calorie-burning process in your body (a lot of those ways involve absolutely no exercise or changes to your diet).
Before we dive in, here's a quick overview of everything that you can expect to learn from this guide:
What is thermogenesis and how it works for weight loss
Thermogenesis is a fancy word for the production of heat in your body. To generate heat, your body needs to burn calories. The more heat your body generates, the more calories you'll burn away (and the faster you'll reach your weight loss goals).
The good news is, you can actively increase your calorie burn rate by triggering thermogenesis in your body (my guide shows you how).
I will not only explain how many calories different kinds of thermogenesis can help you burn away, but will also provide you with actionable tips on how you can improve your weight loss results by boosting thermogenesis in your body.
So let's get to it.
How to increase your calorie burn rate with food (diet-induced thermogenesis)
You probably already know this, but your body needs to spend energy to absorb, distribute, and store the nutrients from the foods you eat.
The harder your meals are to digest, the more extra calories your body will have to burn away to extract the nutrients from them.
Scientists call this process "diet-induced thermogenesis", but it's just a fancy way of saying you can burn away some extra calories on digestion if you pick the right foods.
Before we take a look at how many calories you can burn away digesting different kinds of foods, let me quickly show you how diet-induced thermogenesis actually works.
How diet-induced thermogenesis works in real life
Here's a nice chart I've adopted from a study on diet-induced thermogenesis that shows how your meals increase your calorie burn rate over 24 hours:
As you can see, diet-induced thermogenesis kicks in after every meal (breakfast at about 9am, lunch at noon, and dinner at around 6pm). After it kicks in, your digestion stays revved up and keeps burning away extra calories for hours after your meals.
The chart shows your calorie burn rate can stay elevated well into the night even if you eat your last meal at 6pm. In the study, the calorie burn rate didn't return to the baseline (the dashed line) until about 2am.
But how long into the night you'll keep burning those extra calories away depends heavily on the kind of dinner you eat (we'll get to that in a minute).
How many extra calories can you burn away with diet-induced thermogenesis?
Now, let's take a look at how many extra calories you can expect to burn away if you decide to boost your calorie burn rate with the right kind of foods.
According to a study that compared different mixed diets, we spend 5%-15% of the calories we eat on digestion.
So if you eat a standard diet of 2000 calories, you can count on burning away somewhere between 100 and 300 calories per day just to digest your meals. In other words, if you change your diet in a way that will make sure you're hitting the 300 calories mark, you could burn away as much as 200 extra calories per day on digestion alone.
200 calories every day means you could get rid of almost 2 pounds (1 kilogram) of pure body fat every month. And while diet-induced thermogenesis alone may not be enough to really move the needle, it's still one of the easiest wins you can get.
But remember, the study compared mixed diets. As you'll see, it's possible to burn away even more than 15% of calories on digestion with certain highly thermogenic foods.(If a food is highly thermogenic that means it can increase your calorie burn rate by A LOT.)
So let's take a closer look at what kind of foods will provide the biggest boost to your calorie burn rate.
Skyrocket your diet-induced thermogenesis with protein
Proteins are the absolute winners when it comes to boosting your calorie burn rate with diet-induced thermogenesis.
According to science, you can burn away between 20%-35% of the calories you eat on digestion if you stick to high-protein foods.
In other words, if you eat a 1000 calories worth of protein, you could end up spending up to 350 calories just to digest them.
I'll give you a few examples of how to use this to your advantage in real life later on, but now, let's take a look at another highly thermogenic "food".
A surprisingly high thermogenic effect of alcohol
Even though alcohol is usually considered "empty calories", it still has a big impact on your calorie burn rate. Between 10%-30% of calories you get in with alcohol will be spent on digestion.
So again, drink down a 1000 calories worth of alcohol, and your body could burn away as much as 300 calories breaking down that alcohol.
The biggest problem with alcohol is that people usually add it on top of everything else they eat. So even though you might burn away a few extra calories digesting those tequila shots, your overall calorie intake will still increase.
Plus, alcohol comes with a whole set of problems, so drinking it just because it's highly thermogenic wouldn't really be a healthy option for you in the long run.
How much can carbohydrates and fat boost thermogenesis?
Carbohydrates (carbs) and fat in your meals will provide you with just a minor boost of your calorie burn rate.
Science says you will burn away 5%-10% of calories you get from carbs and only 0%-3% of calories you get from fat.
While carbs will increase your calorie burn rate by a little more than fat, they both don't even come close to what protein and alcohol can do for you. Alcohol and protein can both help you burn away as much as three times more calories on digestion.
But before we take a look at how to put what you just learned in action, I need to warn you about one critical mistake you could make if you try to boost thermogenesis with your diet.
One critical mistake to avoid when increasing thermogenesis with your diet
You can only enjoy the benefits of increased thermogenesis, if you keep getting in about the same amount of calories than before.
If you get in about 2000 calories during the day, and then drink down another 1000 calories worth of alcohol at night, this won't work.
While you would burn away up to 300 extra calories digesting that alcohol, your calorie intake would still increase by 700 calories (a 1000 extra calories ingested - 300 extra calories spent on digestion).
I'm sorry if this sound a bit obvious, but you'd be surprised at how many people struggle to understand this.
So remember, always replace the calories, never just add calories on top of what you normally eat (or that thermogenesis boost won't help you out at all).
Caffeine boosts the thermogenesis in your body surprisingly well
Caffeine has been proven to boost the thermogenesis in your body in quite a few scientific studies.
But caffeine doesn't just help you burn away more calories through thermogenesis.
Science has discovered that caffeine can also help you release more fat from your body fat reserves.
This not only helps you get rid of that stubborn body fat a lot faster, but it also helps protect your lean body mass (that's your muscle mass and vital organ tissue) during rapid fat burn.
And while I can't get into all the details in this article (thermogenesis is just one piece of the puzzle, after all), you can read all about the amazing benefits of caffeine for weight loss in this guide.
Another little known natural substance that boosts thermogenesis
Polyphenols are another substance that has been scientifically proven to boost thermogenesis.
Polyphenols are found in different certain types of teas and work together with caffeine to speed up your calorie burn rate even further.
The best part is, polyphenols have actually been proven to prevent the absorption of some of the fat-calories you eat.
(I can't go into more details here, but if you want more information on how to put polyphenols in real life action, you can read my science-based guide to drinking oolong tea for weight loss).
Drinks like oolong tea contain both polyphenols and caffeine, which means you get to enjoy the benefits of both of these thermogenesis-boosting substances at once.
Now, let's take a look at some real life examples of how to boost your thermogenesis with food.
Real life examples of boosting your calorie burn rate with food
Ok, so now you know that between protein, alcohol, carbs, and fat, only protein and alcohol can provide a good boost of the thermogenesis in your body.
Because replacing your meals with alcohol could bring on a whole new set of issues, the only realistic option would be to replace some of the carbs and fat in your meals with (lean) protein.
Here are a few real life examples of how you can do this:
- eat a green salad with some chicken (more protein) instead of a macaroni or potato salad (more carbs and fat)
- eat meatballs (protein and some carbs) instead of pasta with tomato sauce (lots of carbs)
- eat a steak (protein) with rice on the side (some carbs) instead of a cheeseburger with fries on the side (lots carbs and fat)
- if a nutrition label says two different foods have about the same amount of calories per serving (two yogurt brands for example), but one has more protein and the other has more carbs or fat, then choose the one that's richer in protein
And remember, getting in the same (at least roughly) amount of calories as before is a must. You really won't be doing yourself any favors if you attempt to boost your diet-induced thermogenesis by eating more calories in total.
Thermogenic drinks that speed up thermogenesis
Ok, you've now seen the science on how alcohol, caffeine, and polyphenols are all thermogenic, meaning they can speed up thermogenesis.
But the problem with most drinks containing these thermogenic substances (especially in case of alcohol) is that they also bring a lot of calories to the table.
So, if you're interested in speeding up the thermogenesis in your body for weight loss, you might want to use some low-calorie, or even zero-calorie alternatives.
Let's go over a couple of such examples of thermogenic drinks.
Oolong tea and thermogenesis
As it turns out, oolong tea can be quite thermogenic because it contains both caffeine and polyphenols (and no calories).
And besides being able to boost the thermogenesis in your body, science has discovered a few other benefits of oolong tea for weight loss.
(If you want to learn more about how oolong tea works, how many calories it can actually help you burn, and how much weight it can ultimately help you lose, you can read my science based guide to speeding up weight loss with oolong tea.)
But another highly thermogenic kind of tea will boost the thermogenesis in your body even further than oolong tea...
Green tea and thermogenesis
Yes, just like oolong tea, green tea has been scientifically proven to speed up thermogenesis as well.
In fact, green tea can boost this awesome calorie burning process in your body by 35–43%!
(To learn more about how green tea can help you laser-target that stubborn body fat, how many calories it can help you burn, and how much weight in total it can help you lose, visit my science based guide to drinking green tea for weight loss.)
And just like oolong tea, green tea doesn't contain any calories as well. This puts it among the rare few naturally thermogenic drinks that contain no calories at all.
Let's move on to boosting thermogenesis with slightly more exhausting activities than drinking down a cup of tea every now and then.
How to burn away the most calories AFTER exercise (exercise-triggered thermogenesis)
We all know that exercise can burn away a ton of calories and produce a lot of heat in your body (exercise-triggered thermogenesis), especially if you go really hard.
But the calories you burn away DURING exercise is not what I want to focus on (countless other articles already cover this subject).
Here, we'll take a look at how to burn away as much calories as possible AFTER cardio exercise (running, cycling, swimming, walking, etc.) by exercising in different ways.
Most people don't know this, but as you'll see, research has shown that our bodies can keep burning away extra calories long after you've already stopped exercising.
Scientists call this after-exercise calorie burn "excess postexercise oxygen consumption" (or just EPOC).
Let's take a look at how you should exercise to maximize EPOC and burn away as many extra calories as possible (on top of what you already burned away during exercise).
First, let's take a look at the intensity of exercise (intensity has the strongest effect on EPOC).
Why 800 calories of running is NOT THE SAME as 800 calories of walking
In one study, trained men and women exercised at 70% intensity for 30 minutes. Men burned away 140.5 extra calories and women burned away 121.5 extra calories in the 3 hours after exercise.
In another study, exercising for 80 minutes at 50% intensity burned away 28.5 calories after exercise. But when the same exercise was performed for 80 minutes at 75% intensity, 150.5 extra calories were burned away in the hours following the exercise.
In one more study, people burned away 500 calories by exercising at 50% intensity or by exercising at 75% intensity.
Now, even though they burned away the same 500 calories during exercise in both cases, they burned away 45 extra calories after exercising at 75% intensity and only 24 extra calories after exercising at 50% intensity.
As you can see from the science, the harder you go, the bigger of a calorie burning boost you can expect to get after exercise.
So if you walk for 2 hours and burn away 800 calories, or run for 1 hour and burn away the same 800 calories, the total amount of calories you'll burn away won't be the same.
Because running is more intense than walking, you can expect to burn away more extra calories AFTER running.
See how this works?
Ok, now you know that the harder you go at it, the more extra calories you'll burn away after exercise (on top of what you'll burn away during exercise). Let's move on with how long you should exercise to boost your post-exercise calorie burn rate.
Boost your post-exercise calorie burn rate by exercising longer
In one study, people exercised at the same intensity for 30, 45, and 60 minutes.
After 30 minutes of exercise, people burned away 33 calories over the following 2 hours. After 45 minutes of exercise, people burned away 74.5 extra calories over the next 3.5 hours. After 60 minutes of exercise, people burned away 165 extra calories over the 7.5 hours after exercising.
In another study, people walked at 70% intensity for 20, 40, and 60 minutes.
Again, the longer the exercise session lasted, the more calories people burned away after exercise. For 20-, 40- and 60-minute sessions, they burned away 43, 49, and 76 calories, respectively.
In one more study, people cycled at 70% intensity for 20, 40, and 80 minutes.
In this study, people burned away 55.5, 73.5, and 159.5 extra calories after exercise for the 20-, 40-, and 80-minute exercise sessions, respectively.
Ok, so now we know that both exercising harder and longer can boost your after-exercise calorie burn rate.
Just remember, exercising too hard or too long for your level of fitness CAN be dangerous. Unless you're a 100% healthy individual (only your doctor can confirm that for you) who is already well used to exercise, you should probably avoid long/intense exercise (at least until you build up to a higher level of fitness over time).
Now, let's take a look at another way of upping your post-exercise calorie burn rate (this one is the easiest of all and can work regardless of your level of fitness).
The easiest way of maximizing exercise-triggered thermogenesis
According to research, splitting up a 50-minute run into two 25-minute runs (of roughly the same intensity) has more than doubled the amount of calories you'll burn away after exercise.
In another study, people exercised for 30 minutes at once, or did 2 x 15 minutes of equally intense exercise.
Again, splitting a 30-minute session into two 15-miinute sessions boosted the post-exercise calorie burn rate from 26.5 calories to 37 calories. This isn't as big of a boost as in the first study, but that's because they used less intense exercise than running. Still, the after-exercise calorie burn rate increased by almost 40%.
So that's it. You now know the three ways of maximizing your post-exercise fat burn rates:
- increase the duration of your exercise sessions
- increase the intensity of your exercise sessions
- keep everything else the same and split your exercise time into two (or more) daily sessions
While the first two options are already widely known to increase your calorie burn rate during exercise, you now know all of these will also increase the amount of calories you burn after exercise.
How to use temperature to burn away more calories (cold-induced thermogenesis)
Cold(er) temperatures are the next in line of things that can boost your calorie burn rate.
When the temperature of your environment drops, your body responds by generating more heat (to keep your core temperature the same). Scientists call this effect cold-induced thermogenesis, and again, this process can help you burn away some extra calories.
As you'll see, exposure to cold alone has been proven to boost your calorie burn rate by a whopping 40%. And while it is unrealistic for an average person to start exposing themselves to extreme cold, there's still a lot of things you can do to benefit from cold-induced thermogenesis.
Let's jump right in.
The realistic amount of calories you can burn away with cold
One study took a closer look at people who moved from California to Antarctica and lived there for more than 5 months. Because they switched from a hot to an extremely cold environment, they were able to eat 40% more calories without gaining any body fat.
Because of cold-induced thermogenesis, someone who was able to get away with eating 2,000 calories per day in California (and not gain weight), was able to eat 2,800 calories every day in Antarctica (and still not gain any weight).
But this is an extreme example. In less extreme temperatures, you'll also burn away fewer calories on thermogenesis.
According to research, living in a 60°F (16°C) room will help you burn away around 160 extra calories per day.
In another study, they found out that living in a 66°F (19°C) environment could help you burn away as much as 250 calories per day.
A lot of things besides temperature will decide how many extra calories you can actually burn away with cold-induced thermogenesis. How much body fat you're currently carrying around, how much muscle mass you have, and how many layers of clothes you're wearing are just a few of the factors.
But the bottom line is, the amount of extra calories cold exposure can help you burn off can be quite significant. Even "just" 100 extra calories per day could help you move the needle over time.
So let's look at a couple of different strategies you can start using right away to boost your cold-induced thermogenesis.
Your thermostat CAN help you reach your weight loss goals
A study that involved more than a 1,000 people has shown that the higher the indoor temperature is set, the bigger the waistline can get.
The problem is, with the widespread use of indoor climate control, the average indoor temperatures have been steadily rising over time.
One such study of indoor temperatures in USA from 1987 to 2005 has shown an increase in the night time bedroom temperatures from 66.7°F (19.3°C) to 68.4°F (20.2°C).
Another study done in UK has showed an increase of living room temperatures from 64.9°F (18.3°C) in 1978 to 66.4°F (19.1°C) in 1996.
And it's not just home temperatures. Workplace temperatures have also increased over time.
According to science, even small reductions of indoor temperatures could help you get rid of that stubborn body fat over time.
So lower the temperature in your house/apartment if you can. This will not only help you reduce your waistline, but will should also bring down your heating/electricity bill.
If you're not comfortable with lower temperatures during the day, at least bring them down in your bedroom during the night.
Also, reduce the temperature in your office/workplace if possible.
No need for anything crazy extreme. Just try to do as much as you, and the people who share your living space, can comfortably handle.
Is the climate you're living in keeping you overweight?
A Spanish study looked at different regions with average temperatures between 50.7°F (10.4°C) and 70.3°F (21.3°C). Just like with indoor temperatures, higher outdoor temperatures were connected to bigger waistlines.
Research has also proven that our bodies burn away more calories during months with lower average temperatures (the highest calorie-burn was reached during the coldest winter months).
So here's a couple of tips how you can put all this in action:
- Don't stay inside just because it's a cold day. Remember that the cooler the weather, the more extra calories you'll burn away by just being outside.
- If you always layer up to a point where you feel hot even on an early spring day, you can pretty much forget about any extra calorie burn from feeling a bit chilly.
- Don't heat up your car too much. It's ok to feel a bit cold on your drive to work, you are fully clothed after all.
Again, there's no need for anything extreme. Unless you really know what you're doing, you can forget about ice baths, walking around half-naked in snow, or taking painfully cold showers.
Just try to pick up some new habits that will introduce a bit of "comfortable chill" in your life. Over time, enough of these small changes could help you get rid of a few extra pounds.
Proof that warm temperatures cripple your ability to lose fat
Because the indoor temperatures are slowly increasing over time, and because we spend less and less time outdoor, we're not only burning away less calories overall, but our ability to trigger cold-induced thermogenesis is taking a hit as well.
Studies have shown that the more time you spend in a warm environment, the less calories you'll be able to burn away once you're exposed to cold again.
This does make sense. If your body is almost never required to generate any extra heat on its own, then it's no wonder that it loses the ability to do so over time.
Luckily, your ability to burn away more calories in a cooler environment can be restored. So let's take a look at how to do that next.
How to restore your "cool" calorie-burning abilities
In one study, people spend 2 hours every day at 63°F (17°C) for 6 weeks. By the end of those 6 weeks, their bodies adapted to cold so well, that they were burning away almost 3 times as many calories during cold exposure than before the study.
Another study has shown that our ability to burn away extra calories during cold exposure improves with time.
The boost of the calorie burn rate wasn't nearly as huge as in the first study (where the ability to burn away body fat during cold exposure almost tripled), but this study only lasted for 10 days. This suggests that it might take a while before your body can reach its peak cold-induced thermogenesis.
The point is, if you're serious about getting the highest possible calorie-burn rate boost from cold, you have to keep exposing yourself to cold so your body can reach its peak ability to burn away those extra calories.
The easiest way to do this, is to make changes that will expose you to a bit of chill every single day. Things like reducing your bedroom temperature, or taking daily morning walks without 3 layers of clothes can work wonders in the long run.