Intermittent Fasting Side Effects: What You Need to Know

Intermittent fasting has turn out to be a preferred weight reduction development in recent times. It entails fasting for a sure interval, normally between 16-24 hours, adopted by a interval of regular consuming. Whereas many individuals swear by the effectiveness of intermittent fasting for weight reduction, folks typically overlook the potential negative effects of this food regimen. Any food regimen that requires excessive measures can result in numerous damaging penalties, and intermittent fasting is not any exception.

Whereas weight reduction is important to a wholesome life-style, it shouldn’t come at the price of one’s well-being. Subsequently, sustainable measures selling general well being and long-term weight administration are essential. The next sections of this text will delve into the negative effects of intermittent fasting and why it is important to concentrate to them. By understanding the potential dangers, you may make an knowledgeable resolution about whether or not intermittent fasting is the appropriate method for you or if extra sustainable choices can be found.

Intermittent Fasting: An Overview

Intermittent fasting is a dietary method that entails alternating between intervals of consuming and fasting. The idea of intermittent fasting is simple- alternating between consuming and fasting, with common intervals of consuming little to no energy. There may be plenty of deal with once you eat than on calorie restriction.

The consuming window refers to consuming all of your meals and snacks, whereas the fasting window is once you chorus from consuming. Water and non caloric drinks like inexperienced tea or black espresso are allowed within the fasting window. There are totally different types of intermittent fasting, every with its personal consuming and fasting home windows. As well as, the size of the consuming and fasting intervals can fluctuate relying on the chosen methodology of intermittent fasting.

A few of the hottest variations embody:

Time-Restricted Consuming (TRE)

Time-restricted consuming  entails proscribing the time when meals are consumed inside 24 hours. Typical consuming instances vary from 4–12 hours, with out caloric restriction. The commonest type of TRE is 16:8, with 8 hours of consuming window. It entails consuming inside a particular timeframe each day, usually inside an 8-hour window, and fasting for the remaining 16 hours. The consuming and fasting home windows can swimsuit particular person preferences and existence. Different variations of TRE embody 18:6 and 20:4 consuming schedules. TRE reduces insulin ranges, boosts metabolism, and improves general well being.

Alternate Day Fasting (ADF)

ADF entails consuming as regular for in the future, adopted by a day of fasting, and so forth. Some folks modify ADF by consuming round 25% of their every day energy (about 500 energy) on their fasting days. Because of this, ADF might help with weight reduction and enhance insulin sensitivity.

The 5:2 Food plan

The 5:2 food regimen entails consuming usually 5 days every week and consuming solely 500–800 energy on the remaining two days. This type of intermittent fasting exhibits to be efficient for weight reduction, bettering vitality ranges, and lowering irritation.


This intermediate fasting entails fasting for twenty-four hours a few times every week.

The Warrior Food plan

It entails fasting in the course of the day and consuming a bigger meal at night time.


Intermittent fasting is a dietary method that entails alternating between intervals of consuming and fasting. The timing of the meals is as vital as the standard of meals. Completely different types of intermittent fasting embody time-restricted consuming, alternate-day fasting, the 5:2 food regimen, eat-stop-eat, and the warrior food regimen. Every has its personal consuming and fasting home windows, with various lengths. Intermittent fasting can have a number of well being advantages, together with weight reduction, improved metabolism, and diminished irritation.

Why do Folks Select Intermittent Fasting?

Intermittent fasting has gained reputation as an consuming sample for quite a few causes. Under are a few of the commonest the explanation why folks select intermittent fasting.

Weight Loss

One of many principal causes folks select intermittent fasting is for weight reduction. It’s a extremely efficient device for lowering general calorie consumption, which might result in weight reduction.

Improved Vitality and Focus

Fasting provides the physique a break from digesting meals, which permits it to deal with therapeutic and detoxifying. It could possibly additionally enhance vitality ranges and psychological readability, bettering focus and productiveness.

Higher Metabolic Well being

Analysis exhibits intermittent fasting might help regulate hormones and insulin ranges, main to higher metabolic well being. It could possibly additionally assist in fats burning, benefiting these trying to drop some pounds.

Improved Digestion

Intermittent fasting may give the digestive system a break, permitting it to work extra effectively. As well as, it may result in improved digestion and diminished irritation.

Decreased Irritation

Analysis exhibits intermittent fasting can scale back irritation, reducing the chance of sure illnesses like coronary heart illness.

Advantages for These with Excessive Blood Sugar

Intermittent fasting might help regulate insulin ranges and enhance glucose uptake, making it useful for these with excessive blood sugar. It could possibly additionally assist scale back blood sugar ranges and handle urge for food.

Advantages for Athletes

Intermittent fasting can optimise muscle restoration and scale back fats burning throughout train, bettering sports activities efficiency.


Intermittent fasting has gained reputation for a wide range of causes. It could possibly assist in weight reduction, enhance vitality ranges and focus, profit metabolic well being, assist digestion, scale back irritation, assist these with excessive blood sugar, and profit athletes. Nonetheless, any restrictive food regimen, together with intermittent fasting, can result in negative effects if adopted for too lengthy. Subsequently, adopting sustainable and long-term measures for weight reduction and general well being is essential. Whereas intermittent fasting might provide advantages, you will need to weigh them in opposition to the potential dangers and resolve whether or not it’s best for you.

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10 Unavoidable Facet Results of Intermittent Fasting

Earlier than choosing an intermittent fasting plan, it’s essential to seek the advice of a medical skilled about its potential negative effects. Though some methods might trigger extra negative effects than others, realizing the highest ten widespread negative effects can help you in managing them effectively.

Unhealthy Consuming Habits

Wholesome consuming habits are essential for sustaining general well being and well-being. Fasting might lead to unhealthy meals cravings, significantly for sugary, ultra-processed snacks. As a substitute of fasting to keep up a wholesome weight, it’s higher to determine sustainable consuming habits that embody nutrient-dense meals. Planning wholesome snacks and incorporating them into your food regimen might help you obtain your well being targets with out risking your well being. Subsequently, it’s advisable to keep away from excessive weight-reduction plan strategies like fasting and deal with creating wholesome, long-term habits.

Starvation and Cravings

Whereas intermittent fasting has gained reputation, it’s important to notice that it may generally improve urge for food and cravings for meals. As well as, when beginning fasting, the physique might take time to regulate to the brand new routine, resulting in elevated starvation. A examine on overweight adults confirmed that the 5:2 food regimen and calorie restriction resulted in related weight reduction and coronary heart well being advantages, however the 5:2 group reported extra starvation. 

Listening to your physique and adjusting your fasting schedule accordingly is important. For instance, shortening the fasting window or consuming a restricted quantity in the course of the quick might help scale back starvation. Bear in mind, selecting a sustainable weight reduction method that works greatest for you is essential.


Your physique wants time to regulate once you begin intermittent fasting, and it’s not unusual to expertise a headache, analysis. It could possibly be as a consequence of a drop in blood glucose ranges and caffeine withdrawal throughout fasting. Fasting could make you extra prone to each of this stuff, which might contribute to emotions of dizziness or complications. It’s additionally essential to remain hydrated, as dehydration can worsen complications. 

These heady emotions normally solely occur within the first few days and are usually delicate and manageable. Nonetheless, when you’re vulnerable to complications and quick for greater than 16 hours a day, you might be at a better threat for fasting complications.

Regulating caffeine consumption and sustaining hydration and sleep patterns are important to keep away from frequent fasting complications.

Digestive Points

Research present intermittent fasting has digestive troubles like bloating, constipation, diarrhoea, nausea, and dehydration. Don’t fear; it’s not unusual. Your physique is adaptable, however adjustments in your consuming routine can throw your intestine off stability. Whenever you alter your consuming schedule, your intestine bugs want to regulate, which might trigger tummy troubles. 

As soon as your physique settles in and you aren’t consuming something new, intermittent fasting might help stability your intestine micro organism and scale back irritation, which can minimise abdomen troubles. Nonetheless, the advance in intestine well being over time requires extra analysis.

Irritability and Different Temper Adjustments

Intermittent fasting can generally have an effect on your temper and make you irritable and moody. It’s as a result of when your blood sugar degree drops, you might expertise anxiousness and have issue concentrating. Nonetheless, the accomplishment and pleasure you get once you obtain your fasting targets could make the battle worthwhile.

Some research present that intermittent fasting can enhance signs of tension and melancholy, however that’s not all the time the case for everybody. As a beginner to fasting, you might really feel burdened and crankier initially. Nonetheless, analysis exhibits that many individuals with weight problems expertise enhancements in vitality and temper.

Fatigue and Low Vitality

Intermittent fasting might depart you feeling low on vitality and fatigued, no less than initially. Your blood sugar ranges might drop once you skip meals. It makes you are feeling weak and disrupts your sleep. It’s like that afternoon stoop you expertise the place you solely need to shut your eyes and nap.

For some folks, the fatigue normally subsides as soon as your physique will get used to this new routine. As well as, intermittent fasting improves psychological well being and reduces bodily and psychological fatigue in some instances. So, if you don’t really feel enchancment in your temper over time, please seek the advice of an authorized nutritionist.

Dangerous Breath

In the event you’re doing intermittent fasting, you would possibly expertise unhealthy breath. It’s a widespread symptom referred to as halitosis. A examine reveals that once you quick, your physique makes use of fats for vitality, producing acetone as a byproduct. This acetone could cause your breath to odor funky, like nail polish remover. Moreover, fasting can result in dehydration, which might additionally trigger unhealthy breath. And since dehydration can lower your saliva circulate, your mouth can dry out, worsening the unhealthy breath. So when you’re fasting, remember that unhealthy breath could be one of many negative effects you’ll need to take care of.

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Poor Sleep

In the event you’re making an attempt out intermittent fasting, you might expertise some bother along with your sleep. It could possibly be as a result of your new meal schedule interferes along with your physique’s inner clock. Some research present that sleep disturbances are a typical aspect impact initially, however they have a tendency to lower over time. Nonetheless, different analysis means that intermittent fasting might enhance sleep high quality. 

Extra analysis is required to grasp the connection between intermittent fasting and sleep absolutely, however it’s attainable that meal timing and measurement could possibly be components. Over time, although, intermittent fasting might assist reinforce your inner physique clock and result in higher sleep.


Whenever you quick, your physique loses water and salt by means of your urine, particularly within the first few days. It may end up in dehydration, which might trigger dizziness, complications, and fatigue. Consuming extra water is important when you expertise these signs throughout a quick. Extreme dehydration may even have an effect on your skill to pay attention, keep in mind issues, and have an effect on your temper. So, it’s important to make sure you drink sufficient water throughout fasting. In the event you discover a major color change in urination, it’s a signal that you want to improve your water consumption. It’s no secret that staying hydrated is significant in your general well being. However it’s much more mandatory when fasting.


If you wish to strive intermittent fasting, make sure you don’t leap into it too shortly, or you would have a dietary deficiency. Calorie consumption is usually the main target of fasting, however keep in mind your physique’s dietary necessities. Additionally, do not forget that fasting solely impacts once you eat, not what you eat. And extended fasting can result in malnutrition, leading to unintentional weight reduction, fatigue, temper adjustments, and issue concentrating. 

Consuming nutrient-dense meals like fruits, greens, nuts, seeds, legumes, grains, and fat to remain wholesome. To remain on observe, seek the advice of a dietician and create a nutritious meal plan you possibly can observe throughout fasting. Keep away from proscribing energy excessively, as it may have an effect on your physique’s functioning. 


Intermittent fasting is a well-liked weight reduction method that entails fasting and consuming home windows. Though the advantages are quite a few, it’s important to notice that there are negative effects to pay attention to. Ten widespread negative effects embody unhealthy consuming habits, starvation and cravings, complications, digestive points, irritability and temper adjustments, fatigue and low vitality, unhealthy breath, poor sleep, and dehydration. For some, these negative effects could also be delicate and manageable; most individuals alter after just a few days. Nonetheless, if signs persist or turn out to be extreme, it’s best to seek the advice of a medical skilled.

Who Ought to Not Select Intermittent Fasting?

Intermittent fasting is a widespread apply for bettering well being and reducing weight, however it’s not appropriate for everybody. 

Right here’s who ought to keep away from it:

  • In the event you’re pregnant or breastfeeding, it’s greatest to keep away from intermittent fasting. It may negatively have an effect on your child’s well being and improvement.
  • Aged people who expertise weak point, immunodeficient folks, these with dementia, or a historical past of traumatic mind damage also needs to keep away from intermittent fasting.
  • These with consuming issues like anorexia nervosa or bulimia nervosa ought to keep away from intermittent fasting, because it may exacerbate their situation.
  • For folks with diabetes or on continual medicines, it’s essential to debate fasting with a healthcare supplier beforehand, because it may adversely have an effect on their situation.
  • Lastly, kids and youngsters nonetheless rising and underweight shouldn’t take part in intermittent fasting because it may impede their bodily improvement and general well being.

Bear in mind, intermittent fasting might not be for everybody. Earlier than beginning a brand new dietary routine, one should all the time seek the advice of a healthcare skilled or licensed nutritionist.


Whereas intermittent fasting has gained reputation as a manner to enhance well being and drop some pounds, it’s not appropriate for everybody. Pregnant or breastfeeding girls, aged people, immunodeficient folks, these with dementia or a historical past of traumatic mind damage, folks with consuming issues, and kids and youngsters ought to keep away from intermittent fasting. Moreover, these with diabetes or on continual medicines ought to focus on fasting with a healthcare supplier beforehand.

The Ultimate Phrase

Intermittent fasting can have quite a few well being advantages, together with weight reduction, improved metabolism, and diminished irritation. Nonetheless, one should pay attention to the potential negative effects of this food regimen, and some other food regimen that requires excessive measures, to make a well-informed resolution about whether or not it’s the proper method for you. As well as, adopting sustainable measures selling general well being and long-term weight administration is essential. Subsequently, discovering a balanced food regimen and train routine that works in your life-style is important for reaching long-term weight reduction targets.

Disclaimer: The aim of this text is simply to disperse information and lift consciousness. It doesn’t intend to switch medical recommendation from professionals. For additional info, please contact our licensed nutritionists Right here.

Regularly Requested Questions (FAQs)

Q. What are the widespread negative effects of intermittent fasting? 

A. Intermittent fasting could cause starvation, cravings, complications, digestive issues, irritability, temper swings, fatigue, and low vitality. As well as, it additionally ends in unhealthy breath, insufficient sleep, dehydration, and malnutrition. Nonetheless, these negative effects might not have an effect on everybody, however following a sustainable weight-loss measure is essential to make sure wholesome and long-term weight reduction.

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Q. Is it regular to really feel hungry throughout intermittent fasting? 

A. Sure, intermittent fasting can generally make you hungry and crave meals. In the course of the begin of fasting, your physique would possibly endure an adjustment interval. It’s the place you are feeling hungrier than regular. Nonetheless, the non permanent starvation might not final for lengthy for everybody. However, it’s nonetheless higher to decide on sustainable measures.

Q. Can intermittent fasting trigger complications or migraines? 

A. Sure, throughout intermediate fasting, headache is widespread. It’s due to a drop in blood glucose ranges and caffeine withdrawal throughout fasting. Moreover, dehydration can even lead to complications. Nonetheless, for some folks, it lasts for only some days of fasting. 

Q. Is it protected to do intermittent fasting when you’ve got diabetes? 

A. Nonetheless, it’s thought-about that intermediate fasting helps regulate insulin ranges and enhance glucose uptake. Folks with diabetes ought to focus on this with healthcare suppliers earlier than a fasting regime, which can lead to hostile impacts.

Q. Can intermittent fasting result in dietary deficiencies? 

A. Sure, intermediate fasting may result in dietary deficiencies. Additionally, extended fasting may end up in malnutrition, resulting in unintentional weight reduction, fatigue, and issue focusing. Subsequently, guarantee it is best to eat nutrient-dense meals throughout your non-fasting interval.

Q. Does intermittent fasting trigger muscle loss? 

A. A number of research reveal that intermittent fasting results in the lack of lean muscle mass. Nonetheless, when you eat an sufficient or high-protein food regimen, you don’t have to be involved about shedding muscle with short-term intermittent fasting. However it’s best to decide on extra sustainable and wholesome measures for many who purpose for long-term outcomes.

Q. Can intermittent fasting have an effect on my menstrual cycle? 

A. Sure, intermediate fasting can have an effect on menstrual cycles in girls. It’s as a result of girls’s reproductive techniques are delicate to calorie restrictions. Meaning extended fasting can have an effect on the oestrogen that’s important to the menstruation course of. 

Q. Are there any damaging impacts of intermittent fasting on sleep high quality? 

A. Sure, intermediate fasting can bother your sleep. It is because of your new dietary schedule, which interferes along with your physique clock. Nonetheless, for some, it’s a minor aspect impact of fasting, lasting only some days. However for some, it could be a long run aspect impact. Therefore, one ought to search for extra sustainable and wholesome methods.

Q. Can intermittent fasting result in elevated stress ranges? 

A. Sure, intermediate fasting results in elevated stress ranges. It’s as a result of intermediate fasting can improve cortisol ranges, a stress hormone. Subsequently, in case you are doing intermediate fasting for a very long time, it makes you burdened.

Q. Is it protected to train whereas doing intermittent fasting?

A. Sure, it’s completely protected to train whereas doing intermediate fasting. It reduces fats burning throughout train and improves sports activities efficiency by optimising muscle restoration. 

Analysis Sources

1. Patterson RE, Laughlin GA, LaCroix AZ, Hartman SJ, Natarajan L, Senger CM, Martínez ME, Villaseñor A, Sears DD, Marinac CR, Gallo LC. Intermittent Fasting and Human Metabolic Well being. J Acad Nutr Food plan. 2015 Aug;115(8):1203-12. doi: 10.1016/j.jand.2015.02.018. Epub 2015 Apr 6. PMID: 25857868; PMCID: PMC4516560.

2. Aly SM. Position of intermittent fasting on bettering well being and lowering illnesses. Int J Well being Sci (Qassim). 2014 Jul;8(3):V-VI. DoI: 10.12816/0023985. PMID: 25505868; PMCID: PMC4257368.

3. Sundfør TM, Svendsen M, Tonstad S. Impact of intermittent versus steady vitality restriction on weight reduction, upkeep and cardiometabolic threat: A randomised 1-year trial. Nutr Metab Cardiovasc Dis. 2018 Jul;28(7):698-706. doi: 10.1016/j.numecd.2018.03.009. Epub 2018 Mar 29. PMID: 29778565.

4. Torelli P, Manzoni GC. Fasting headache. Curr Ache Headache Rep. 2010 Aug;14(4):284-91. DoI: 10.1007/s11916-010-0119-5. PMID: 20490742.

5. Wilhelmi de Toledo F, Grundler F, Bergouignan A, Drinda S, Michalsen A. Security, well being enchancment and well-being throughout a 4 to 21-day fasting interval in an observational examine together with 1422 topics. PLoS One. 2019 Jan 2;14(1):e0209353. DoI: 10.1371/journal.pone.0209353. PMID: 30601864; PMCID: PMC6314618.

6. Anic Okay, Schmidt MW, Furtado L, Weidenbach L, Battista MJ, Schmidt M, Schwab R, Brenner W, Ruckes C, Lotz J, Lackner KJ, Hasenburg A, Hasenburg A. Intermittent Fasting-Brief- and Lengthy-Time period High quality of Life, Fatigue, and Security in Wholesome Volunteers: A Potential, Scientific Trial. Vitamins. 2022 Oct 10;14(19):4216. doi: 10.3390/nu14194216. PMID: 36235868; PMCID: PMC9571750.

7. Harvie M, Howell A. Potential Advantages and Harms of Intermittent Vitality Restriction and Intermittent Fasting Amongst Overweight, Obese and Regular Weight Topics-A Narrative Overview of Human and Animal Proof. Behav Sci (Basel). 2017 Jan 19;7(1):4. DoI: 10.3390/bs7010004. PMID: 28106818; PMCID: PMC5371748.

8. Anderson JC. Measuring breath acetone for monitoring fats loss: Overview. Weight problems (Silver Spring). 2015 Dec;23(12):2327-34. DoI: 10.1002/oby.21242. Epub 2015 Nov 2. PMID: 26524104; PMCID: PMC4737348.

9. Almeneessier AS, BaHammam AS. How do diurnal intermittent fasting impression sleep, daytime sleepiness, and markers of the organic clock? Present insights. Nat Sci Sleep. 2018 Dec 7;10:439-452. doi: 10.2147/NSS.S165637. PMID: 30573998; PMCID: PMC6292409.

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