MythBusters: Does Intermittent Fasting Slow Metabolism

    Slow Metabolism

    Martin Alvarez

    Martin Alvarez
    Nutritionist/Dietitian Professional Guide

    Updated on 12/3/2022

    You may have read or heard from a friend that intermittent fasting will decrease your metabolism. If so, you may have explored intermittent fasting for weight reduction, which makes little sense if reducing unneeded fat in the body is one of your primary objectives. You are not obligated to trust everything you read or hear, which is a huge relief. We will talk in this article about Does Intermittent Fasting Slow Metabolism yes or no

    There is no evidence suggesting that practicing intermittent fasting will slow your metabolism. On the contrary, restricting the amount of time you spend eating can help boost your metabolism and provide other benefits to your health, such as lowering your blood pressure and making it easier for you to get to sleep at night.

    In the event that you are contemplating adopting a healthier lifestyle but are concerned about the potential adverse effects that intermittent fasting may have on your metabolism, Simple has compiled all the information you require to make an educated choice in this matter.

    Do You Know What The Big Deal Is About Metabolism?

    Do You Know What The Big Deal Is About Metabolism?

    Your research about losing weight may have led you to the term "metabolism" at least once in all of your research about losing weight. However, what exactly is metabolism? Your cells undergo a chemical procedure known as metabolism to turn the fuel you get from meals into usable energy. People usually carry out the metabolic process while they are sleeping or resting.

    As soon as food enters your digestive system, enzymes begin converting carbs into glucose for use as fuel, transferring fat into fatty acids, and breaking down proteins into amino acids. One way to conceive of this is through which calories are burned or energy is created. When you consume more calories than your body requires as a source of fuel, those extra calories become stored as fat in your body.

    The term "basal metabolic rate" (BMR) refers to the rate at which your body consumes calories for energy while at rest, and scientists use it to assess this. If your basal metabolic rate (BMR) is low, you will burn fewer calories when at rest, and if you eat the same amount of food as someone of comparable size but with a higher BMR, you will likely accumulate more body fat. But how exactly does it alter your basal metabolic rate (BMR)?

    What Happens To Your Metabolism When You Do Intermittent Fasting And How It Affects Your Body

    What Happens To Your Metabolism

    When you go without food for a lengthy period, your metabolism undergoes many adjustments. In the first place, the body is always searching for new approaches to producing different kinds of energy. Your body typically breaks down the carbohydrates in the food you eat into glucose, which is used to power your body. When you go without food for an extended period, your body is forced to produce glucose using resources other than carbohydrates. Gluconeogenesis is the name given to this process.

    In the process of gluconeogenesis, your body converts glycogen stored in your liver and water stored in your tissues into glucose for energy. When your body's glycogen stores are depleted, it searches for alternative fuel sources, such as amino acids, because carbs are no longer an option. The more the frequency with which your body seeks alternate sources of energy, the higher the amounts of specific metabolites that are found in your blood.

    When You Do Intermittent Fasting And How It Affects Your Body

    In particular, researchers have discovered a significant rise in the products of the citric acid cycle, which enables the cells in your body to release previously held energy. Your cells are sent into overdrive when citric acid metabolites rise, causing them to produce and store surplus energy for you to use while you are fasting. Put another way, when you deprive your body of food, it doesn't slow down; instead, it goes into overdrive.

    Does The Practice Of Intermittent Fasting Raise The Levels Of Hormones That Burn Fat?

    The Levels Of Hormones That Burn Fat?

    Hormones are the natural messengers that are produced by your body. They are responsible for coordinating most of your body's processes, including managing your weight, hunger, and the growth of your muscles. Hormones not only affect the amount of fat you store or burn, but they also have a significant impact on your metabolism. There is a correlation between the practice of intermittent fasting and improvements in the synthesis of your body's metabolism-boosting hormones, such as insulin, human growth hormone (HGH), and Norepinephrine. Intermittent fasting can also help you lose weight.

    Insulin is a hormone that plays a pivotal role in metabolizing fat. It does this by sending signals to your body about when to start storing fat and when to stop breaking it down, which significantly impacts your basal metabolic rate. Not only may having high insulin levels make it more challenging to lose weight, but they can also raise the risk of developing heart disease and type 2 diabetes. Studies have shown that practicing intermittent fasting may lower insulin levels by anywhere from 20 to 31 percent, making it simpler to keep your weight under control while also speeding up your metabolism.

    Does The Practice Of Intermittent Fasting Raise

    The human growth hormone, often known as HGH, is an essential hormone that plays a role in both the maintenance of muscle mass and the promotion of fat loss. Researchers have discovered that going without food for one day can boost HGH production by 1,300 percent in women and 2,000 percent in men. Your basal metabolic rate (BMR) and overall efforts to lose weight can benefit from a rise in HGH, promoting the metabolism of protein and carbohydrates.

    In conclusion, there is a correlation between the practice of intermittent fasting and a rise in Norepinephrine. This stress hormone stimulates the release of fatty acids from the fat cells in your body. When more Norepinephrine is circulating in the bloodstream, a more significant amount of fat is made accessible for the body to burn. This release of fat makes it easier to lose weight and may also enhance the functioning of your metabolic systems.

    Does Fasting During Intermittent Periods Slow Down Your Metabolism?

    Does Fasting During Intermittent Periods

    Despite the widespread belief that it will have the opposite effect, which is to slow down your metabolism, intermittent fasting has the potential to have the opposite effect. Researchers have discovered that following a fasting regimen such as the 16:8 method can rev your metabolism to a higher level. [citation needed]

    According to research by the University of Vienna, going without food for three days can boost your metabolism by 14%. Researchers believe that an increase in Norepinephrine is the reason for a surge in metabolism, and Norepinephrine is responsible for helping to make more fat available to be burned. You may get the same variation in Norepinephrine with a milder fast, even if a short-lasting three days would seem like an excessive measure to take. According to some research, fasting for just 12 hours might help boost metabolic processes and reduce weight.

    Effects On Metabolism Caused By Traditional Diets VS. Those Caused By Intermittent Fasting

     Those Caused By Intermittent Fasting

    If you are curious about how intermittent fasting differs from conventional diets, such as tracking calories, it may have the same impact on your metabolism as intermittent fasting. That's not conceivable from a purely physical standpoint. The only way for your body to undergo the hormonal and metabolic shifts during intermittent fasting is to go without food. Even though calorie-restricted diets reduce the total amount of food you consume, you are nevertheless always eating something. Consequently, your body will use carbs or sugars digested rather than any other fuel sources already present.

    To get down to brass tacks, the prolonged periods of eating less ultimately enable your body to experience beneficial improvements in metabolism. It is impossible to simulate the effects of intermittent fasting by reducing the number of calories you consume or eating fewer calories at each meal.

    Why Counting Calories Can Lead To Malnutrition And A Plateau Effect In Your Diet


    The theory behind intermittent fasting is that if you fill your body with the appropriate nutrients during your feasting window, you can sustain a fast without jeopardizing your health. The idea here is that if you eat in a way that is both nutritionally sound and correct during your feasting window, your body will be able to attain nutritional deficiencies even though you are still eating. On the other hand, restricting calories reduces the total amount of food you consume throughout the day, which might leave you vulnerable to nutritional deficiencies even if you are eating. If you severely reduce the number of calories you down for a lengthy period, your body may go into "starvation mode."


    Your body's natural response to famine, which can occur if you cut your calorie intake below what your body requires, is called starvation mode. When you are in hunger, you may experience lethargy, irritability, and fatigue. Even worse, it can lower your basal metabolic rate (BMR). In addition, research has shown that famine brought on by a reduction in calorie intake might permanently slow the metabolism.

    When your metabolism begins to slow, it might cause a situation known as a plateau, in which your weight loss stops appearing to progress. After reaching a weight loss plateau, going on a diet that severely restricts your calorie intake makes it more likely that you will put on the weight you previously lost.

    Myth Busted: The Effects Of Intermittent Fasting On Metabolism

    the Effects Of Intermittent Fasting On Metabolism

    Does fasting for shorter periods at intervals slow down your metabolism? The evidence suggests not at this time. The good news is if you have been hesitating to try intermittent fasting, now is the time to do it so that you may reap all of its benefits without experiencing any slowdown in metabolism. As per reading this article you should know Does Intermittent Fasting Slow Metabolism yes or no