Intermittent Fasting: A Guide For Beginners

About intermittent fasting

The eating plan that is designed to switch between periods of fasting and having meals regularly is called intermittent fasting. Research identifies that intermittent fasting is a method used for weight management to prevent weight gain. It is also used to reverse some of the health conditions related to obesity.1

Since the number of people with obesity and metabolic illnesses is growing rapidly, many cures have been developed which keep focusing on individual food and exercise routines. Intermittent fasting is becoming a well-known dietary practice in today’s world but the roots are from various cultural, spiritual, and religious traditions in the past. Recent studies show that intermittent fasting has more benefits than just weight loss and calorie restriction.2 Other benefits include but are not limited to modification in the production of energy, enhancing appropriate organ functions, and generally improving physiological health. Moreover, it also helps to manage systemic inflammation, and prevent and treat other chronic health conditions. We will discuss these benefits in detail later on in this article. 

Intermittent fasting may seem overwhelming and you might wonder whether this fasting will be workable for you and whether it will match your routine. Don't worry! We have a solution. In this article ahead, we will discuss some of the different ways of doing intermittent fasting. So if you're planning to start it today, you can choose whichever method fits your lifestyle best. 

Intermittent fasting: how to get started

There are numerous different types of intermittent fasting but it is essential to experiment first to identify which one is suitable. It depends on your schedule to decide the duration of your fasting period.

Let us first understand the different types of fasting methods that are commonly used.3

  1. Complete alternate-day fasting (ADF): Alternating the fasting days with eating days is one of the ways to perform intermittent fasting. It is either avoiding eating completely or having small meals of less than 500 calories (calorie restriction) every alternate day. For example: if you choose to fast on Mondays, Wednesdays, Fridays, and Sundays, then you will be eating a normal diet on the remaining days. This is only possible when you have a flexible routine and fewer other commitments to function on.3
  2. Modified Fasting Regimens: This is also called the 5:2 dietary approach, in which 5 represents the five days of the week when there is no restriction and a person can eat as much as they  desire.While there are two days of less consumption of energy around 20-25%. These days are also called energy restriction days.3
  3. Time-Restricted Eating (TRE): This type focuses on when you eat rather than what you eat. It follows specific time frames when you can eat and fast either daily or nightly as per the timetable. For instance, 20:4, 16:8, 14:10, and 12:12 — where the first number indicates the hours of fasting and the second number is the hours of having meals.3 In this method, some people may skip their breakfast but according to research, the morning meal has been recognized as one of the most important meals of the day as it benefits children as well as adults in many important ways. It helps in providing complete nutrition, lowering the body mass index (BMI), enhancing cognitive performance, and improving the quality of life.4
  4. Religious fasting: Many religions have different fasting regimens to follow for spiritual purposes.3


  • RULE # 1: NEVER SKIP A BREAKFAST: Make sure to start your day with a healthy breakfast because it helps to boost our metabolism and gives us energy for the rest of the day. With reference to a very famous saying: "Eat breakfast like a king, lunch like a prince, and dinner like a pauper" — eating breakfast will make you healthier and richer (in health) like a king. 
  • RULE # 2: EAT SMALL MEALS A DAY: Make sure to eat six small meals per day so that your body keeps operating and you have maximum capacity all day long. 

Timed fasting can have positive impacts on our sleep and overall health. Our body’s internal clocks are often triggered by eating habits. It is beneficial to fast overnight so that our metabolic and cardiac system functions normally. Eating at these intervals may negatively affect the body’s system leading to disruptions in our energy levels.5

IMPORTANT: It is crucial to be cautious while intermittent fasting if you have any underlying health conditions. It is recommended to perform fasting under supervision or with medical advice. 

Benefits of intermittent fasting

Since intermittent fasting is growing rapidly, people are also noticing many benefits of this fasting method. Many studies have also proved that different types of intermittent fasting have different benefits. 

  1. EFFECTS ON BODY WEIGHT: All types of intermittent fasting (ADF, 5:2, and TRE) have shown a mild (1%) to moderate (8%) weight loss from the baseline in most people.6 Fasting can lead to a shortage of glucose in the body which is required for energy production, thus body cells break down the stored fat instead. Hence leading to increased weight loss. This process is called ketosis.7 Keto diet is one of the examples of meals which is usually taken for such purposes. 
  2. EFFECTS ON METABOLIC DISEASES RISK: Taken into account altogether, all forms of intermittent fasting have shown a modest fall in blood pressure. ADF and 5:2 fasting methods have also been identified to significantly reduce cholesterol and triglyceride levels in the body. However, the timed-restricted method exhibited less change in the levels of plasma lipids.6 This support by intermittent fasting on blood pressure and lipid levels have constructive impacts on our cardiac and respiratory conditions. Furthermore, reduction in insulin resistance and HBA1C levels have also been a consequence of intermittent fasting in healthy people with obesity and pre-diabetic conditions. Type 2 diabetics have also improved their glycemic control with a 5:2 dietary approach.6 For diabetes patients, it is recommended to be aware of the diabetic diet that is advisable and seek help from dietitian and nutritionists before practicing any fasting methods. 

Fasting may also have other benefits for our bodies: 

  • It helps to improve our appetite by increasing the feeling of fullness. Thus, maintaining the amount of food eaten leads to a reduction in obesity and weight loss.
  • Improving sleep quality and duration is another advantage of intermittent fasting. As discussed prior, our body's clocks depend on our eating patterns and timings.6


What should I eat before and after fasting

Before we get into the pre-fast and post-fast meals, it is important to first prepare our bodies for the fasting days to avoid going into a state of shock. It is usually advised to follow a regular and balanced dietary routine which is based on high nutritional values. Food intake should be divided into five to six small meals per day and must include whole grains, fresh fruits and vegetables, nuts, beans, legumes, and daily use of olive oil. Plant-based meat and fish are suggested over red meat.8

What is recommended for a pre-fast meal?

It is recommended to select natural and healthy foods as they cause less harm to the body. Cooked vegetables, baked chicken, tossed salad, or a fresh fruit dessert would be the best options to choose from. Most of these foods provide fiber to the body which helps to increase fullness for a longer duration. Drinking water is recommended to keep away discomfort during fasting hours. It also keeps the body free of fatigue, headaches, and cravings.9

What to eat at the time of breaking the fast? So now you would be hungry enough that you would like to eat anything that comes into your sight first. BUT WAIT! You have to remember the purpose of fasting and break your fast accordingly. It is important to eat something which is light on your stomach and helps you digest quickly. Avoid drinks and unhealthy food to keep our bodies on track. Food with low fiber like eggs, dairy products, and fish are recommended. You can have some fruits of your choice as well to add minerals and vitamins to the diet.8

How long should I fast as a beginner

The length of fasting depends on various factors like the purpose of fasting, how flexible your routine is, and how adaptable your body is. But if you are a beginner, it is advisable to experiment first before fixing yourself on a fasting schedule to avoid health complications (hypoglycemia, malnutrition, or other eating disorders).  

If you’re a beginner and learning how to fast: START SLOW. You can start with the 12:12 hours fasting method initially and when you get comfortable, it is recommended to increase your fasting time then. Make sure to drink plenty of water and avoid fasting on exercise days because that may make you feel dehydrated and drain your energy leading to complications.  

Some studies found that alternate-day fasting of 24 hours and time-restricted fasting of 16 hours is important for many physiological changes in human bodies that prevent chronic diseases if practiced for longer periods, but the variations in duration, frequency, and longevity can have different effects on different individuals. Thus, it is advisable to find a fasting regimen according to your lifestyle and body requirements.10

Does drinking water or any beverages affect fasting

Fasting helps in the reduction of glucose which leads to the breakdown of fats (ketosis). It also assists in reducing insulin levels. It is well known that solid foods and carbonated and sweetened beverages may counteract the function of intermittent fasting. However, water is not associated with increased sugar or insulin levels in the body. Hence it is considered a safe option to prevent dehydration unless you are opting for dry fasting— a fasting method that doesn't allow any foods or liquids (including water). 

Who should and should not do intermittent fasting

Some people do intermittent fasting for managing their weight, and others use this measure to combat chronic health conditions such as high blood glucose levels, high cholesterol, arthritis, etc. But intermittent fasting is not for everyone.1

It is recommended to check with your medical practitioner before you begin this fasting. Although some studies suggest that intermittent fasting is beneficial for people with diabetes as it improves insulin sensitivity, the American Diabetes Association doesn't recommend fasting as management for diabetes.8 Similarly, for people with cardiac conditions it is considered both beneficial and harmful at the same time. 

Populations that are recommended to avoid intermittent fasting are: 

  • Children and adolescents: It is physiologically and psychologically dangerous for this age group.
  • Pregnant or breastfeeding women and the elderly population (more than 75 years old): These people need accurate and precisely developed dietary plans according to their conditions. It is recommended that they completely avoid fasting. 
  • People with recurrent infectious states: Our immune system requires energy to perform better as infections already deplete our immunity. It is essential to complete the body's nutritional requirements. 
  • Underweight/mal-nutrition condition.
  • People with a history of eating disorders. 
  • Shift workers.8

Things to remember

A few pointers that must be remembered before, while, and after  performing intermittent fasting: 

  • Intermittent fasting may seem difficult but there are many forms that you can choose according to your flexibility. 
  • It is important to experiment with every method before fixing up on one dietary lifestyle.
  • Never skip your breakfast - it makes you live like a king.
  • Eat small, frequent meals to avoid overburdening your stomach. 
  • Drink plenty of water 
  • Don’t eat heavy foods for breaking the fast—IT WILL SPOIL THE PURPOSE OF FASTING. 
  • Check with your doctor before starting to fast.

Keep it easy on your body and your lifestyle - Do not rush. 


Intermittent fasting is a pattern of combining fasting and eating periods together. It is rapidly growing in today's world as people are using this fasting method for weight management and surviving other health conditions. There are many forms of intermittent fasting but it is recommended to experiment with them all and choose the one which best suits your body and lifestyle. Though there are many health benefits of intermittent fasting, it is still advisable to check with your medical doctor before proceeding with the regimen to avoid any further complications. Overall, intermittent fasting is about you and your body so don’t rush and make it easy for yourself. 


  1. Intermittent Fasting: What is it, and how does it work? [Internet]. 2022 [cited 2022 Nov 19]. Available from:
  2. Gu L, Fu R, Hong J, Ni H, Yu K, Lou H. Effects of intermittent fasting in human compared to a non-intervention diet and caloric restriction: a meta-analysis of randomized controlled trials. Frontiers in Nutrition [Internet]. 2022 [cited 2022 Nov 19];9. Available from:
  3. Patterson RE, Laughlin GA, Sears DD, LaCroix AZ, Marinac C, Gallo LC, et al. Intermittent fasting and human metabolic health. J Acad Nutr Diet [Internet]. 2015 Aug [cited 2022 Nov 19];115(8):1203–12. Available from:
  4. Ferrer-Cascales R, Sánchez-SanSegundo M, Ruiz-Robledillo N, Albaladejo-Blázquez N, Laguna-Pérez A, Zaragoza-Martí A. Eat or skip breakfast? The important role of breakfast quality for health-related quality of life, stress and depression in spanish adolescents. Int J Environ Res Public Health [Internet]. 2018 Aug [cited 2022 Nov 19];15(8):1781. Available from:
  5. Patterson RE, Sears DD. Metabolic effects of intermittent fasting. Annu Rev Nutr [Internet]. 2017 Aug 21 [cited 2022 Nov 18];37(1):371–93. Available from:
  6. Varady KA, Cienfuegos S, Ezpeleta M, Gabel K. Cardiometabolic benefits of intermittent fasting. Annu Rev Nutr [Internet]. 2021 Oct 11 [cited 2022 Nov 19];41(1):333–61. Available from:
  7. Intermittent fasting for weight loss [Internet]. Mayo Clinic Health System. [cited 2022 Nov 19]. Available from:
  8. Attinà A, Leggeri C, Paroni R, Pivari F, Dei Cas M, Mingione A, et al. Fasting: how to guide. Nutrients [Internet]. 2021 May 7 [cited 2022 Nov 19];13(5):1570. Available from:
  9. 5 tips for healthy fasting [Internet]. Cleveland Clinic. 2022 [cited 2022 Nov 19]. Available from:
  10. Horne BD. Considerations for the optimal timing, duration, frequency, and length of an intermittent fasting regimen for health improvement. Nutrients [Internet]. 2020 Aug 25 [cited 2022 Nov 19];12(9):2567. Available from:
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

Get our health newsletter

Get daily health and wellness advice from our medical team.
Your privacy is important to us. Any information you provide to this website may be placed by us on our servers. If you do not agree do not provide the information.

Amira Samnani

Bachelor of Science in Nursing- The Aga Khan University Hospital, Pakistan

Amira is a Registered Nurse with demonstrated clinical experience of working in health care industry. She has a 4 years of experience as a practicing nurse in Internal Medicine-Adult care unit. She is proficient in her knowledge about health education and promotion. Currently, she is seeking roles in her field while continuing her education to become health and wellness expert.

Leave a Reply

Your email address will not be published. Required fields are marked * presents all health information in line with our terms and conditions. It is essential to understand that the medical information available on our platform is not intended to substitute the relationship between a patient and their physician or doctor, as well as any medical guidance they offer. Always consult with a healthcare professional before making any decisions based on the information found on our website.
Klarity is a citizen-centric health data management platform that enables citizens to securely access, control and share their own health data. Klarity Health Library aims to provide clear and evidence-based health and wellness related informative articles. 
Klarity / Managed Self Ltd
Alum House
5 Alum Chine Road
Westbourne Bournemouth BH4 8DT
VAT Number: 362 5758 74
Company Number: 10696687

Phone Number:

 +44 20 3239 9818