Intermittent fasting or time-restricted feeding as it is sometimes called is a general term that is used to describe a situation where periodic breaks are taken from eating.  Mattson et al. (2017) explained it a bit more succinctly as a particular eating pattern where an individual would go without food for extended periods (for example, 16-48 hours).  The fast would then be broken with periods of normal food intake. 

Nonetheless, while the practice may appear like ‘just another fad’ due to its seemingly rapid popularity over the past few years, research has dictated otherwise.

Some of the purported benefits associated with this practice include its positive impact on cardiovascular health, diabetes and most commonly, weight loss.  But, is it just another fad or a lifestyle that is worth more than just a glance?  Well, let’s explore.

In this article, we will be discussing five (5) scientific benefits of Intermittent Fasting as well as how you can incorporate it into your lifestyle as you continue on a path of health and wellness scientifically proven. Let’s discuss!

What is Intermittent Fasting?

Intermittent fasting is a type of practice where people refrain from eating food (preferably solid) for extended periods, called the fasting period.  Food is then introduced as normal for another extended period, then the cycle continues for days or for whatever desired duration based on the purpose and other lifestyle factors of the particular individual. 

This practice or lifestyle has not only gained momentum among persons on a quest to lose weight or to promote overall health but also researchers who have been investigating its effects on the body and how its practice could improve one’s overall health as well as prevent the development of certain chronic or debilitating conditions such as diabetes, cancer and brain disorders.

Research by Martin et. al. (2006) sought to investigate just how this form of restrictive eating as well as caloric restriction could help with some of the vulnerabilities of the nervous system which can lead to the development of neurodegenerative disorders such as Alzheimer’s and Parkinson’s disease. A finding of the research suggests that intermittent fasting could help the body at the cellular level, especially how it responds to stress which could protect neurons against both genetics and environmental factors which would otherwise become issues during the aging process.

Further, research contends that intermittent fasting in general triggers metabolic adjustments in the body which can lead to weight loss and other health benefits.  This is because this type of eating pattern could cause a shift in the way the body utilizes glucose as fuel for fatty acids or what is known as derived ketones. This in turn represents a situation where the body transitions from storing fat to using up fat (fat metabolization) (Anton et al. 2018). 

However, research purports that long-term success will be dependent on what one eats during the ‘eating cycle,’ as this can not only cause weight gain but other adverse effects on the body.  As such, one must ensure that this practice is coupled with healthy eating habits of essential nutrients (micro and macronutrients). 

Thus far, it is certainly proving to be a practice that can have a positive impact on the body. But, let’s see what science continues to say.  In this article, we will explore five (5) scientifically proven benefits of intermittent fasting.  These include its positive effects on brain health, inflammation, obesity and weight loss, cardiovascular health and hypertension and finally, life span and aging.

5 ‘must know’ Health Benefits of Intermittent Fasting (IF):

Intermittent fasting is far more than a fitness trend; it’s a tool rooted in biological science. By shifting the body’s metabolic state, this practice triggers a cascade of cellular responses that go well beyond simple calorie cutting. From hormonal optimization to neurological protection, here are five scientifically proven benefits of adopting a fasting protocol:

1. Intermittent Fasting and Brain Health

Research has shown that the deprivation of food or caloric restriction can have a positive impact on the brain. Research suggests that such practices can result in a decrease in the size of most of the organs of the body except the brain and testicles in male mice (Weindruch and Sohal, 1997).  This is due to the fact the body tries to maintain a high level of cognition under conditions of food scarcity. As such, the behavioural traits of all mammals indicate that they become active (when hungry) but sedentary, when full (Longo and Mattson, 2014).

This was confirmed in a study of rodents when normal feeding and fasting were done on alternating days, their brain function was enhanced which was shown in performance on behavioural tests of sensory and motor function (Singh et al. 2012). Learning memory was also shown to improve (Fontan-Lozano et al. 2007).

Additionally, another study by Lil and Zuo (2013) also showed that intermittent fasting or time-restricted feeding was able to improve memory and learning.  As such, the way the brain responds under intermittent fasting conditions is associated with an increase in synaptic plasticity and an increase in the production of new neurons from stem cells (Lee et al. 2002).

Further, research has shown that the body’s adaptive responses to the brain during times of limited food could also enhance exercise performance.  This is due to the evolution of the brain-derived neurotrophic factor (BDNF) which regulates energy. 

BDNF signals in the brain cause behavioural and metabolic responses to fasting and exercise which also include the regulation of one’s appetite, glucose metabolism as well as the cardiovascular system (Mattson, 2012, b; Rotham et al. 2012).

2. Intermittent Fasting and Inflammation

Research suggests that long-term fasting, particularly those lasting up to three (3) weeks was shown to have beneficial effects in the treatment of those suffering from rheumatoid arthritis.  Rheumatoid arthritis is a disease that affects the joints of the body due to inflammation.  The effects of rheumatoid arthritis and intermittent fasting were seen in a study conducted by Muller et al. (2001) on rodents. In this study, it was found that inflammation and pain were reduced in rheumatoid arthritis patients during the period of the fast. 

However, inflammation resumed when the patients returned to eating a normal diet. Therefore, according to research, for the results to be realized in the long term, recommended that the fasting period must be followed by the inclusion of a vegetarian diet (Kjeldsen-Kragh et al. 1991).  The combination of these two (2) methods was observed to be even more beneficial when both intermittent fasting and a vegetarian diet were practised for at least two (2) years or longer (Kjeldsen-Kragh et al. 1994).

The approaches in these studies were supported by several other controlled studies which included randomized trials (Muller et al. 2001).  As such, it was concluded that intermittent fasting combined with a vegetarian diet or some other modified similar diet could serve as a beneficial treatment for rheumatoid arthritis due to its potential to reduce inflammation in the body, which then reduces pain.

3. Intermittent Fasting and Obesity and Weight loss

Research has shown that intermittent fasting or time-restricted fasting can help with weight loss. This is so because intermittent fasting involves the intake of fewer calories when one is in restricted mode, particularly overnight fasting.  For example, a pilot study in 2019 by Kesztyus showed a two (2) inches reduction in the waist circumference of researched participants who practice 15-16 hours of intermittent fasting (Keszytus, 2019).

This research was also confirmed in another 2019 pilot study where it was observed that overweight participants who fasted for at least 16 hours overnight for a month experienced an average weight loss of almost six (6) pounds (Anton et al. 2018). 

The study by Anton et al. (2018) reported that participants also experienced an improvement in walking speed and mental function. The effects of intermittent fasting were also observed to improve other areas of ill health such as blood pressure, blood sugar and cholesterol (Wilkinson et al. (2019).  The study by Wilkinson et al. (2019) was observed after a Fourteen (14) hour fast by participants of the study. 

The overall conclusion was that intermittent fasting was found to be equally effective as a calorie-restriction diet for weight loss (Rynders et al. 2019).

4. Intermittent Fasting and Cardiovascular health and Hypertension

Research has shown that intermittent fasting has a positive effect on low-density lipoprotein (LDL) cholesterol (bad cholesterol) as well as triglycerides and one’s overall cholesterol levels. This was because an eating pattern of this nature had the potential to prevent the formation of atherosclerotic plaque (Malinowski et al. 2019).  

Additionally, intermittent fasting or time-restricted fasting was also shown to significantly reduce blood pressure after a Fourteen (14) hour overnight fast (Wilkinson et al. 2019).  The study also reported weight loss due to a significant reduction in body fat and waist circumference.

You can read more on cardiovascular health and hypertension in these articles:

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5. Intermittent Fasting and Lifespan (including aging)

Lifespan can be a controversial topic, as life is so uncertain. However, biological lifespan refers to the maximum number of years a human can live (sciencedirect.com) while maximum lifespan usually speaks to the mean life span of the most long-lived human or the maximum life span (age) at which the oldest known member of a species has died (Gavrilov and Gavrilova, 1991), including circumstances that are optimal to that particular member longevity.

Nonetheless, studies over the years have shown the beneficial effects on health and one’s general well-being due to caloric restriction and intermittent fasting over time.  One such research was an animal study that was conducted as far back as 1935 by McCay and some other researchers (McCay et al. 1935).  

In that study, both the mean and maximum lifespan of the mouse, the subjects of the study, were extended with a diet containing only indigestible cellulose (Insoluble fibre found in fruits, vegetables and plants).

These results have been confirmed by several other studies since, including one by Weindruch and Walford, 1988 as well as Sprott (1997).  These studies, however, were conducted on mice and other species.  Other variations of intermittent fasting such as ‘every-other-day-feeding’ were shown to also be able to extend lifespan as well as proofing other beneficial effects on one’s health (Sohal and Weindruch, 1996; Goodrick et al. 1982; Ingram and Reynolds, 1987).

Researchers also found that rodents who maintain a form of calorie-restricted diet are usually smaller and leaner and also have less body fat.  These mice also had smaller major organs than animals that ate more often in general (Weindruch and Sohal, 1997).

Research also showed that these animals were also more active which may be due to the need to be constantly searching for food (Hart and Turturro, 1998, etc.). The only major downside of the practice of intermittent fasting and caloric restriction diet on these animals was their vulnerability to cold temperatures, which can cause death, especially for small animals (Johnson et al. 1982).

Additionally, intermittent fasting was shown to decrease the risk factors for certain ill-health conditions such as diabetes and cardiovascular disease (Anson et al. 2003; Wan et al. 2003).  Further, an intermittent fasting feeding regimen for a period of two (2) to four (4) months was also shown to reduce certain neurons associated with the prevalence of certain neurodegenerative disorders such as Alzheimer’s, Huntington’s and Parkinson’s diseases (Bruce-Keller, et. al. 1999a).

Importantly though, the amount by which lifespan is extended will depend on several factors such as the duration of the intermittent fasting or caloric restriction diet. However, research has shown that lifespan is progressively extended the more caloric intake is reduced as such, if practised in the long-term, will have more effect on one’s life span and quality of life.

While intermittent fasting has been shown to retard aging and some age-related diseases (Stranahan and Mattson, 2012), it was found to not extend the mean lifespan and even reduce the lifespan in the genetic background of mice when the practice is initiated at ten (10) months of age (Goodrick et. al. 1990). 

It was also found to either increase longevity or have no effect when initiated at 1.5 months of age (Goodrick et al. 1990). However, more studies are needed to better understand how the different types of fasting mechanisms can play a role in longevity/pre-mature death and one’s overall quality of life in the long term.

How to do Intermittent Fasting – The methods involved

There are many variations of intermittent fasting cited in research as well as in the social media domain.  Importantly, the methods chosen will be unique to an individual’s lifestyle or overall health and wellness goals.  However, three (3) main methods are cited in the research.  All of these methods involve some form of splitting one’s day or week into periods of eating and fasting. 

These methods include ‘every-other-day fast (EODF) or Alternate-day fast, Five to Two (5:2) – Five days of normal eating and 2 days of restrictive eating weekly and the time-restricted fasting or overnight fast as known medically (Stockman et al. 2018).

1. Every Other Day Fast (EODF) or Alternate-Day Fast

As the name dictates, this method of fasting occurs when intermittent fasting is practised every other day. As such, an individual will practice normal/regular eating on one day and refrain from food or reduce caloric intake on the next.  Research has shown this type of fasting is capable of improving one’s lifespan and overall health (Weindruch, 1996; Goodrick et al. 1982, etc.).

Healthy aging was also observed as a beneficial aspect of this type of intermittent fast practice (Varady and Hellerstein, 2007).

2. Five to Two (5:2) periodic fasting or whole day

The 5:2 method is where an individual will practice normal eating for five days in a particular week and the remaining two (2) days are used as fasting days. Similar methods of this type of intermittent fasting (periodic or whole day fast) occur when an individual fasts for one or two days per week or an entire day/s for a particular week. 

There is also an extreme version where people may fast for several days a week. During the fasting period, calorie intake is usually restricted.

3. Time-restricted Intermittent Fasting

This type of intermittent fasting involves only eating for a certain number of hours each day or skipping a meal. A popular form of this method is the 16:8 intermittent fasting where one fasts for 16 hours and has an 8-hour feeding window. Additionally, this is one of the most used methods, with several variations as it pertains to the number of hours for fasting and feasting.

Are there any known side effects in practising Intermittent Fasting?

Some of the noted side effects according to reviews of some preliminary clinical studies suggest that intermittent fasting in the short term may cause minor adverse effects which include the prolonged feeling of hunger, irritability and in some cases impaired thinking. 

According to research, most of these effects will go away on their own within a month of practising this lifestyle (de Cabo and Mattson, 2020). While most of the studies on intermittent fasting did not appear to focus on adverse effects specifically, a review in 2018 did not find any major adverse effects Cioffi et. al. 2018).

Be mindful of Binge eating during your normal eating or feasting hours. This was one of the recommendations by researchers who suggest, that coming off a long fast may result in one ‘overeating’ as the body tries to compensate for ‘loss time.’ This might lead to weight gain or other unwarranted situations, so bear that in mind, start slow and work with your body as it becomes acclimatized to whatever method you choose to practice. 

Remember too, that intermittent fasting is not just about weight loss, but rather incorporating it as a lifestyle and practising eating healthily in general.

Who should not practice Intermittent Fasting?

Intermittent fasting is not recommended to be practised by pregnant or breastfeeding women, children and adolescents or individuals who are susceptible to eating disorders such as anorexia or bulimia (Diet Review, 2018.). Studies have shown that any type of consistent fast could increase the risk of a relapse for persons who had previously suffered from an eating disorder (Hoffman and Gazella, 2020). 

The practice is also not recommended for persons who have higher nutrient needs (Bazzano et al. 2018).

While intermittent fasting has been shown to possibly benefit persons with type-2 diabetes (Albosta and Bakke, 2021), persons with type-1 diabetes should practice caution with this type of lifestyle. This is because people with type-1 diabetes are at a greater risk of ketoacidosis. Diabetic Ketoacidosis is a situation in which the body does not have enough insulin to allow blood sugar to enter the cells for use as energy.

This results in the liver breaking down fat for use as fuel, a process called – Ketones. When the body produces too many ketones too fast, they can build up in the body to dangerous levels, causing diabetic complications (cdc.gov).

Additionally, persons who suffer from blood sugar issues, especially those who experience episodes of hypoglycemia should not practice this method of eating (Hoffman and Gazella, 2020). Therefore, persons with both type-1 and type-2 diabetes or those with other chronic illnesses should consult their healthcare provider for proper supervision, particularly in glucose management (diabetes) before embarking on a practice of this nature. 

Short or long-term – Should I be concerned about the duration of Intermittent Fasting?

Fasting or energy restriction for long hours has been proven to be more beneficial, especially when it comes to weight loss or certain other conditions. For example, intermittent fasting for 10 to 14 hours or more has been found to have significant positive effects on the cells throughout the body and brain (de Cabo and Mattson, 2019).

This is due to a special process where free fatty acids are transported into hepatocytes, leading to the production of ketone bodies. The ketone bodies then activate transcription factors, which both produce and release protein factors which then affect the cells of the body and the brain (de Cabo and Mattson, 2019).

Additionally, intermittent fasting such as 12 to 16 hours or 14 hours has been shown to affect weight loss (Adawi et al. 2017). As such, fasting for 12 hours or less did not show to have any effect on weight loss (Chaix et al. 2014).  However, one clinical human trial showed a 1.3% weight loss for an Eleven (11) hour fast when compared to a controlled study (LeCheminant et al. 2013). 

It must be noted that in this study, the participants reduced their caloric intake during feeding hours.  Research also showed that improved outcomes can be even more achieved when the feeding periods focus on the consumption of healthier foods.

Illustrative Summary

Here is an Illustrative Summary of the Five (5) Scientific Benefits of INTERMITTENT FASTING

Let’s Sum Up!

Intermittent Fasting is increasingly gaining momentum both in research and as a lifestyle practice.  This is due to the many purported benefits that have been reported. This includes its effect on cognition and thus brain health, obesity and weight loss, particularly due to its ability to metabolic adjustments and calorie reductions.  

Additionally, benefits, as discussed, include its effects on lifespan and overall well-being, cardiovascular health and hypertension and inflammation, which if not managed, can lead to the development of certain chronic diseases, including rheumatoid arthritis.

However, while research has shown a myriad of benefits, a few minor side effects such as prolonged feelings of hunger and irritability have been noted.  Nonetheless, these usually disappear within a month of the practice as the body becomes acclimatized. 

Nonetheless, intermittent fasting is not for everyone, especially pregnant or breastfeeding women, and those with certain eating disorders such as anorexia or bulimia.  Caution or special medical professional advice is recommended for those with type 1 and 2 diabetes, blood sugar issues or other chronic medical conditions.

Despite some of the cautions and effects, intermittent fasting has been proven to be a lifestyle that can be safely practised by many persons without any adverse effects. Research has constantly demonstrated its efficacy both in the short and long term.  

However, one must ensure that this practice is coupled with healthy eating habits of essential nutrients (micro and macronutrients) as well as exercise. Importantly, as well, we must remember that no two persons are alike, we are all unique creatures. 

As such, intermittent fasting may work for some, beautiful and quite the opposite for others. Therefore, listen to your body and speak with your healthcare provider if you decide to take on this lifestyle.

All in all, many researchers have reported scientific benefits associated with this eating practice.  As such, one could safely say it is certainly not a fad, despite its popularity, particularly for weight loss, but a practice that could benefit one’s overall health and well-being both in the short and long term.

So, have you ever practised Intermittent Fasting? How was it? Share it with us nuh!

You can read more about diets and their benefits in the articles below:

• Let’s Talk Diet: The ketogenic (Keto) Diet – Benefits and some Cautionary tales!

• The Mediterranean Diet: Benefits, Foods and How to Follow It
  

Editor’s Note: This article was last updated by a Researcher and Certified Nutrition Coach on May 11, 2026.