Last Updated on November 9, 2023 by Fasting Planet
Everyone wants a fast metabolism so you can burn through foods quicker without gaining weight. You’ve recently started intermittent fasting to drop a few spare pounds, and you wonder what its effect on your metabolism will be. Is it possible that you could speed up your metabolism through fasting, or would the opposite happen and you end up slowing your metabolism?
Your metabolism can slow through fasting, but it would have to be a prolonged fast. Since most intermittent fasts are start-stop by nature, there’s little risk of your metabolism decreasing on a fast. If anything, it may get faster.
In this article, we’ll explain exactly why prolonged periods of not eating will affect your metabolism as well as how to fast for a quicker metabolism. If you’re looking to lose weight on a fast, you’re not going to want to miss this!
Understanding Your Metabolism
When you consume food, how quickly that is burned for energies is dictated by your metabolism. Metabolism encompasses two functions: anabolism and catabolism. Anabolism is cell compound synthesis or a substance buildup while anabolism regards how food molecules are broken down to generate energy.
Your metabolism can be faster, which means that compared to someone else at your age and weight, you burn through the foods quicker than they do. Speedy metabolisms are very sought-after because those who have them tend to be slimmer and may even struggle to put weight on. A stronger metabolism can also help you on your weight loss journey and burn fat more easily. Not being able to lose weight is common and extremely frustrating even if weight loss is not guaranteed.
Compare that to a slower metabolism. For these people, it takes longer for your body to use foods for energy. This can lead to easier weight gain and more struggles with losing weight.
How fast or slow your body metabolizes the food you are eating isn’t necessarily something you have a say in. These factors all influence, and as you can see, many of them we have no control over.
- Deficiencies in diet
- Nicotine and caffeine consumption
- Daily exercise
- Temperature
- Hormonal systems and nervous systems
- Genetics
- Gender
- Age
- Body fat percentage
- Lean muscle tissue percentage
- BMI
Does Fasting Slow Your Metabolism?
Now that you know the factors that dictate your metabolism, to you, it might make more sense to skip eating for longer periods. You can lower your BMI and your body fat that way. If you get enough exercise and maintain lean muscle tissue, then surely your metabolism will become faster, right?
Not necessarily.
It all depends on how long you’re fasting and plan to start eating. If you’re on an intermittent fast, where the fasting window lasts for 24 to 72 hours, then you shouldn’t have to worry about slowing your metabolism. If you fast for days upon days and even weeks at a time though, then there’s a possibility your absorption could begin inching to a crawl.
So says this 2015 study in the American Journal of Clinical Nutrition. Another study on the topic, this time in a classic report from the same journal from 1987, reviewed the status of subjects after a three-day fast.
All men involved in the study, six total, were in good health and younger. They fasted for three days.
The participants had a lower resting metabolic rate that decreased by eight percent. Your resting metabolic rate, also known as a basal metabolic rate, is how many calories your body burns when you do nothing. Well, you do nothing, but your neurological system and organs are still at work, your blood is still circulating, you’re still breathing, and your heart is still beating, so your body is busy.
One’s resting metabolic rate can change as you gain fat. You’d burn 0.01 kilocalories a minute fewer for each one percent of body fat you add on. Since the men in the study were fasting, it’s not implied that they gained weight elsewhere, yet their resting metabolic rate still dropped.
Why does this happen? Well, you may know that you’re fasting, but your body doesn’t. All it realizes is that you were feeding it X number of calories before, and now it’s getting very few or no calories. To keep you alive, adjustments must be made.
Your body thus decreases your metabolic rate so you can preserve more of your power. Since your metabolism is slower, it’s easier to put weight on so you can stay alive.
Can Intermittent Fasting Speed up Your Metabolism?
A 1994 study in the British Journal of Nutrition and one from a 1990 edition of Metabolism both found that it’s possible to boost your absorption by doing brief fasts, such as an intermittent fast.
In the first study from the British Journal of Nutrition, a group of men and women were split into three groups to fast for different periods. All participants were in good health. Some fasted for 12 hours, others for 36 hours, and the third group for 72 hours.
The group fasting for 36 hours had a slightly higher heart rate, but no blood pressure changes. Their resting metabolic rate went up “significantly,” which did not happen when fasting for only 12 hours.
If you go on an intermittent fast that lasts for more than 12 hours, you should be able to give your metabolism a boost.
You can also try these things for a faster metabolism:
- When not fasting, use coconut oil instead of cooking fats, as its medium-chain fats could boost your absorption according to a 1989 study in Metabolism.
- Consume coffee in between fasts, as data from the Annals of Nutrition and Metabolism and a slew of other studies note it may be possible to see an increase in metabolism by three to 11 percent.
- If you don’t like coffee, then drink plenty of oolong tea or green tea. In a 2005 edition of the British Journal of Nutrition, as well in several other studies, researchers found that your metabolism can increase by four to five percent when you drink more of these teas.
- Sleep at least eight hours a night, which can ward off obesity.
- Consume peppery foods (if you can stomach them) when not fasting. The capsaicin within peppers can give your absorption a lift, says a 2006 report in Physiology & Behavior.
Conclusion
Shorter-term fasting does not slow your metabolism, but longer-term fasting can. Your body will slow things down to hold onto each calorie it has left so you have the energy for survival. By fasting in quicker bursts, such as through intermittent fasting, you can turn your metabolism around so it’s faster.