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Alternate Day Fasting: Benefits, Methods, Risks And More


Since fasting offers many health advantages, people have been fasting for unknown times. In the past, people were hunters and could go on for long stretches without eating.

When the stomach is empty, our body tries to clean itself of dead cells, hazardous mutant cells, and poisons. In addition, the body tries to utilize ketones as fuel when it enters fasting mode, in addition to this cleansing system.

The body produces ketones by metabolizing fat storage. We should still cause these reactions by fasting, which might lead to outcomes like weight reduction.

Alternate Day Fasting, also known as ADF, might be suitable for some individuals. On the other hand, one could avoid alternate day fasting and intermittent fasting if you are pregnant, or if you want to fast, you should speak to your doctor.

The same is true if you have any lingering medical conditions.

When practicing alternate day fasting, one ends up consuming significantly fewer calories every day. People might do this to maintain a healthy weight or improve certain health elements.

In this article, we will look at alternate day fasting, its benefits, safety, and a lot more.

Alternate day fasting

What Is Alternate Day Fasting?

Alternate day fasting involves alternating between days of unlimited eating and days of calorie restriction. You could fast strictly, which involves consuming no calories at all.

You could also fast moderately, which permits you to ingest only 24% of your daily energy requirements or 600 calories. This review[1] presented the health effects of following the alternate-day fasting regimen.

Food could be consumed all at once or in shorter meals spread throughout the day during fasting. As long as meals have less than 600 calories, they might have either a low or high-fat content.

Either purchase packed meals or prepare your food from scratch with predetermined calorie counts. In the majority of studies, black coffee, water, sugar-free gum, and unsweetened tea were also permitted.

Foods high in fiber and protein could help you feel less hungry while on a modified fast, and soups might make you feel full without adding many calories.

There are not any strict guidelines for what to eat on a feast day. Alternate day fasting is about when to eat, not how much or what.

One should keep in mind that it is always crucial to select nutritious meals which are of excellent quality for general health.

Benefits Of Alternate Day Fasting

Here are some benefits of alternate-day fasting:

  1. Diabetes Management

    The 2016 review included several studies where alternate day fasting was linked to a decreased level of both insulin and blood glucose.

    However, more research[2] is necessary to determine whether ADF improves diabetes and different metabolic illnesses in a clinically relevant way.

    A diabetic patient who is considering modifying their diet needs to consult a dietitian or doctor for help. Those who choose ADF should pay close attention to how their sugar levels are fluctuating.

    This is to ensure that there is less chance of dangerously low sugar levels during fasting days.

  2. Improves Body Composition

    Essentially, alternate day fasting forces your body to regenerate new cells. New cell membranes are used in place of the old ones through recycling.

    Old fat cells are destroyed and used as fuel. Human growth hormone rejuvenates aging muscle cells. You shall be leaner, younger, and fitter as a macro-level outcome of all these small improvements.

    Fasting might boost autophagy. It is the scientific term for the cellular recycling process which renews cells, according to this study[3] on isolated human cells, worms, rats, and flies.

  3. Cardiac Health

    Maintaining a healthy weight is a crucial first step in preventing cardiac disease, according to the Centers for Disease Control and Prevention (CDC).

    This is due to the additional strain that obesity places on the blood vessels and heart. Losing weight could be necessary for certain individuals to maintain a healthy lifestyle. This entails consuming fewer calories.

    But how one achieves this might not be as crucial. Alternate day fasting might be as successful[4] as following a consistent calorie-restricted diet.

  4. Loss Of Weight

    Many people who start ADF see noticeable, rapid weight loss. Their body is losing some of its glycogen reserves because of this. Each gram of glycogen is linked with five grams of water. But the benefits of fasting for weight loss go much further than that.

    According to studies, after 2 to 10 weeks of alternate-day fasting, a person might have lost 10% of their body weight. According to those figures, a 150-pound person could anticipate losing 15 pounds in a few weeks to a few months.

    However, different research[5] has shown that when it comes to belly fat reduction, inflammatory state, or weight loss, ADF is no more effective than traditional calorie restriction.

    While ADF was doable among non-obese people, researchers observed that hunger during fasting days did not reduce. It reflects the unlikelihood to follow this diet for a long period.

    The study also recommended that non-obese alternate-day fasters should try including a little snack on their fasting days.

Who Could Try Alternate Day Fasting?

For those who are planning on a calorie-restricted meal but do not feel like lowering their caloric intake each day, alternate-day fasting might be a good option.

Eating days, when extra calories are consumed, could be more simple or gratifying than adhering to a consistent lower calorie diet. But some people might prefer to escape the extreme hunger that comes with fasting.

According to one study[5] comparing alternate day fasting with daily calorie restriction, there was a greater dropout rate for those who tried the ADF meal.

In general, there are lots of strategies to eat fewer calories. To achieve this, one should experiment with several strategies and choose the one which suits them the most.

How To Follow Alternate Day Fasting?

ADF entails alternating between days of eating and days of fasting.

  1. Days Of Fasting

    A person consumes 26% of their daily calorie intake on these days. Additionally, individuals are free to consume as many calorie-free beverages as they wish, such as herbal infusions, water, and tea.

    Some ADF programs urge individuals to only consume liquids in the morning and to consume the majority of their calories at one small meal, which could be either at lunch or dinner.

    A few low-calorie, modest meals spaced out throughout the day are advised by different regimens[6].

    Both of these ADF programs help obese people improve their heart health and lose weight, claims a 2015 study. In the end, a person should select the strategy which is most practical for them.

  2. Days Of Eating

    A person should eat 126 percent of their daily recommended calorie intake on eating days. In general, a person might select the eating schedule and the diet which suits them the most.

    On days when you fast, the extra calories help to make up for the deficit. But overall, a person consumes fewer calories.

    If weight loss is the aim, having these eating days might make it simpler to establish a calorie deficit.

What To Consume On Days When You Are Fasting?

There is not a set guideline for what to drink or eat when you are fasting. You should only make sure that your daily calorie intake should not go beyond 600.

On days when you are fasting, it is ideal to have low-calorie or calorie-free beverages, such as:

  • Coffee.
  • Tea.
  • Water.

The majority of individuals believe that eating one large meal late in the day is optimal, however, certain people prefer to eat earlier or spread their meals out over a few.

It is essential to put your attention on high protein, nutritionally dense foods as well as low-calorie vegetables as your calorie intake could be severely constrained. These[7] shall fill you up without adding many calories.

On days when you are fasting, soups might also be an excellent choice as they usually make you feel fuller than if you only ate the ingredients separately.

Is Alternate Day Fasting Safe?

Alternate day fasting is safe for the majority of people, according to studies. It has the same risk of weight gain as calorie-restricted, conventional diets.

Although some believe that ADF increases the likelihood of binge eating, this research[8] suggests that it could aid to minimize depressive symptoms and binge eating.

Additionally, it might help obese people who are prone to negative body image perception and restrictive eating.

But the additional investigation is required into the security and efficiency of ADF for those who have tendencies toward eating disorders.

Having said that, alternate day fasting could be inappropriate for some populations. These include women who are pregnant, young children, people who have medical conditions like Gilbert Syndrome, and underweight individuals.

Although some studies indicate that ADF might be useful for lowering binge eating symptoms, this dietary pattern is inappropriate for those with eating disorders, such as anorexia nervosa or bulimia.

If you are currently taking any drugs or have a medical problem, be sure to speak with a healthcare professional before attempting this eating pattern.


ADF could be inappropriate for certain people as they enjoy feasting over fasting. Some people might also want to refrain from the hunger which comes with fasting.

One could eat a low-calorie fiber or protein diet, as well as water-rich, fibrous vegetables and fruits, to boost sensations of fullness when fasting.

Alternate day fasting is not appropriate for all people. Before attempting any sort of fasting, a person should consult a doctor if they have an underlying medical condition, are expecting, or are breastfeeding.

In some circumstances, it might be preferable to conventional calorie-restricted diets. It is also connected to notable advancements in a lot of health indicators.

The best part of all is that you only need to diet every alternate day, making it shockingly simple to maintain.


Working4Health prefers using primary and verified references. We have strict sourcing guidelines and our primary references include peer-reviewed research, academic, and medical institution studies.

  1. Yuanshan Cui, Tong Cai, Zhongbao Zhou, et al. Health Effects of Alternate-Day Fasting in Adults: A Systematic Review and Meta-Analysis Front Nutr. 2020; 7: 586036.Published online 2020 Nov 24. doi: 10.3389/fnut.2020.586036
  2. Kelsey Gabel, Cynthia M. Kroeger, John F. Trepanowski, et al. Differential effects of alternate day fasting versus daily calorie restriction on insulin resistance Obesity (Silver Spring). 2019 Sep; 27(9): 1443–1450.Published online 2019 Jul 22. doi: 10.1002/oby.22564
  3. Grant M Tinsley, Paul M La Bounty Effects of intermittent fasting on body composition and clinical health markers in humans Nutr Rev. 2015 Oct;73(10):661-74. doi: 10.1093/nutrit/nuv041. Epub 2015 Sep 15. Available from: https://pubmed.ncbi.nlm.nih.gov/26374764/
  4. Bartosz Malinowski, Klaudia Zalewska, Anna Węsierska, et al. Intermittent Fasting in Cardiovascular Disorders—An Overview Nutrients. 2019 Mar; 11(3): 673.Published online 2019 Mar 20. doi: 10.3390/nu11030673
  5. John F. Trepanowski, Cynthia M. Kroeger, Adrienne Barnosky, et al. Effect of Alternate-Day Fasting onWeight Loss, Weight Maintenance, and Cardioprotection Among Metabolically Healthy Obese Adults JAMA Intern Med. 2017 Jul 1; 177(7): 930–938.doi: 10.1001/jamainternmed.2017.0936
  6. Corey A. Rynders, Elizabeth A. Thomas, Adnin Zaman, et al. Effectiveness of Intermittent Fasting and Time-Restricted Feeding Compared to Continuous Energy Restriction for Weight Loss Nutrients. 2019 Oct; 11(10): 2442.Published online 2019 Oct 14. doi: 10.3390/nu11102442
  7. B J Rolls, I C Fedoroff, J F Guthrie, et al. Foods with different satiating effects in humans Appetite. 1990 Oct;15(2):115-26. doi: 10.1016/0195-6663(90)90044-9. Available from: https://pubmed.ncbi.nlm.nih.gov/2268137/
  8. Victoria A Catenacci, Zhaoxing Pan, Danielle Ostendorf, et al. A randomized pilot study comparing zero-calorie alternate-day fasting to daily caloric restriction in adults with obesity Obesity (Silver Spring). 2016 Sep;24(9):1874-83. doi: 10.1002/oby.21581. Available from: https://pubmed.ncbi.nlm.nih.gov/27569118/

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