Home » Vegan Intermittent Fasting: The Ultimate Guide

Vegan Intermittent Fasting: The Ultimate Guide

Vegan Intermittent Fasting

Intermittent fasting is becoming incredibly popular across the ‘dietsphere’. It’s been recommended by almost every dietician, researcher and influencer as a way to improve almost every health marker known to man.

It’s key to point out that much of the focus on intermittent fasting has been from ‘diet agnostic’ doctors who often include animal products in their nutrition plan. The topic of vegan intermittent fasting has been widely overlooked; but it’s certainly worth discussing.

If you’re eating a plant-based diet and thinking about squeezing your meals into a shorter portion of the day; you’ve come to the right place. This complete guide dives into every pro, con and caveat you should expect from combining intermittent fasting with a vegan diet.

What is vegan intermittent fasting?

‘Intermittent fasting’ refers to an eating pattern in which you cycle between periods of eating and fasting. It’s an umbrella term that can encompass many different eating and fasting time schedules depending on the individual.

Common intermittent fasting schedules range from fasting for a period of time each day (aka ‘time-restricted feeding’), or fasting two full days per week (aka the 5:2 diet). Each fasting protocol is best suited to a different individual and can yield dramatically different results.

It’s worth pointing out that intermittent fasting is a completely ‘diet agnostic’ term. It only refers to when you eat, as opposed to what you eat.

In this guide, we are discussing vegan intermittent fasting. This means we will discuss how you can combine eating a plant-based diet with periods of feeding and fasting.

Vegan Empty Plate
Intermittent fasting requires time spent with an empty plate

What are the most common types of vegan intermittent fasting?

Time-restricted feeding

This type of fasting involves incorporating a period of fasting into every day. Typically a person will fast for a large portion of the day/night and squeeze their food intake into a specific ‘feeding window’.

The most common form of time-restricted feeding is known as 16:8. It’s a pattern that involves fasting for 16 hours and eating for 8 hours over each 24 hour period (e.g eating only between the hours of 12pm and 8pm).

It’s key to note that time-restricted feeding doesn’t specify the length of time you must fast and feed. It’s another umbrella term that could refer to anyone fasting for a specific portion of each day; typically from 12–20 hours.

Time-restricted feeding is the most popular form of vegan intermittent fasting. It’s easily accessible to almost any plant-based individual and its potential benefits or pitfalls have been well documented.


OMAD is a short for ‘One Meal Per Day’. It means eating only one meal over the course of each 24 hour cycle, usually resulting in 23 hours of fasting and one hour of feasting.

Just like all forms of intermittent fasting: OMAD does not subscribe to a specific dietary philosophy. It’s a term that describes when you eat, not what you eat.

The weight loss benefits of OMAD have also been well studied and recognized as largely positive. One controlled trial saw a significant loss of fat mass over a 6 month period by participants eating only one meal per day.

Eating only one meal per day often results in a high level of caloric restriction that can have remarkable results when applied to the correct individual. Combining this fasting method with a vegan diet is likely to accelerate weight loss due to a possible further reduction in caloric intake; although it’s certainly not a solution for everyone.

The 5:2 Diet

The term ‘5:2’ refers eating ‘normally’ for 5 days per week and fasting for 2 days per week. It does not specify a specific pattern of when to place your fasting days. You could fast for 2 days in a row each week or fast for 2 separate days in every 7 day cycle.

It’s worth noting that 5:2 dieters often allow up to 500 calories of food during their fasting days. Although it’s debatable whether this constitutes a ‘fast’, it’s a viewed as a way of mimicking a complete fast without the potential pitfalls.

The 5:2 diet is most commonly associated with weight loss due to the high level of caloric restriction it can exert across the week. In fact, its ability to reduce body weight and prevent metabolic disease has been affirmed by this 2018 randomized controlled trial.

Alternate-Day Fasting

Alternate-day fasting refers to a cycle of fasting every other day. It’s a form of intermittent fasting that’s designed to significantly reduce long-term caloric intake, which will inevitably be associated with weight loss.

Studies on its efficacy are few and far between, with the one small trial showing poor results. The study found that participants in the alternate-day fasting group did not produce superior adherence, weight loss or cardio protection in comparison to a control group following a daily calorie restriction diet.

The disappointing study result above might point to the difficulty of maintaining an alternate-day fasting diet. Poor adherence on fasting days and overconsuming calories on feeding days are likely outcomes due to this diets challenging nature.

However, anecdotal and theoretical evidence suggests that it could still be considered a valid form of vegan intermittent fasting for the right individual. Inducing a fasted state on a bi-daily basis could garner fast weight loss and health results, providing you’re sticking to a whole-food plant-based diet throughout.

Clock with walnuts (Fasting)
Vegan intermittent fasting combines a plant-based diet with spending time not eating

Why should vegans intermittent fast?

If you’re already eating a whole-food plant-based diet; you’re probably already getting the maximum dietary bang for your buck. However, many are now under the impression that ‘when you eat holds the same importance as what you eat’.

In my opinion; optimal nutrition is a synergy of eating the right foods at the right time. Implementing intermittent fasting is a way to eat in alignment with your circadian rhythm, restrict calories, reduce insulin levels and induce the body into a state of repair.

Vegan intermittent fasting can take these benefits to a whole new level. It combines the ‘breaking down’ of the body during fasting with the ‘rebuilding’ of the body during feeding. When this building phase is completed by ingesting nutrient dense plant foods; you’re constantly upgrading and remodeling your biology.

Allowing the body to clear out waste products and ‘reset’ is hugely beneficial and is only truly possible when in a fasted state. Digesting food around the clock never allows the body to focus on other tasks, such as repair, rebuild and rejuvenation.

DNA Repair After Fasting
Fasting can repair protective DNA coating

What are the benefits of vegan intermittent fasting?

Weight Loss

The vegan diet has long been associated with maintaining a healthy body composition. It’s a fact that’s well demonstrated by the Adventist Health Study’s findings that BMI increases as the amount of animal products in the diet increases.

Intermittent fasting has also proven to be an effective weight loss tactic. In fact, a recent systematic review of 27 trials concluded that ‘intermittent fasting shows promise for the treatment of obesity’. However, they also noted that trials have been ‘small and of short duration’.

Combining a confirmed weight loss diet (vegan) with a promising weight loss method (intermittent fasting) has a strong probability of yielding results. In addition, the anecdotal evidence from this combination is incredibly strong. In fact, I subscribe to this diet/fasting combination myself and have seen remarkable changes in body composition.

The methods by which intermittent fasting aids weight loss are hotly debated. Some believe that it’s all due to caloric restriction, while others feel that fasting allows the body to switch into ‘fat burning’ mode by reducing insulin. I personally feel that both theories are correct and work in tandem to produce results.

Lowers Blood Glucose and Insulin

A vegan diet is traditionally high in carbohydrates. Even if you’re eating whole-food plant-based; it’s likely you’re still taking in vast amounts carbohydrates, even if they are from healthy sources.

Fruits, vegetables, beans and whole grains are commonly seen as the sacred foods of veganism. Each of these food groups has extremely high nutrient density and health benefit, but they all have the capacity to raise blood sugar and stimulate insulin.

Some believe this to be an issue that causes premature aging and possible disease, while others think it’s only an issue in the context of an unhealthy diet. Either way; it’s worth noting that a proven way to lower blood sugar levels is through intermittent fasting.

Vegan intermittent fasting can be viewed as a way to enjoy carbohydrate rich whole foods without the ‘collateral damage’ of elevated blood sugar levels. Spending time without ingesting food will allow your body to ‘burn off’ excess sugar before your next feeding window.

Disease Prevention

If you’re already eating a plant-based diet; your chances of preventing disease are greatly improved. Clear evidence points to the fact that a vegan diet can improve diabetes, cholesterol, cardiovascular and blood pressure issues.

In addition, intermittent fasting has shown promise in preventing and reversing a range of lifestyle related diseases. Significant study data is now showing benefits including improvements in risk factors for diabetes, cardiovascular disease and cancer.

In essence; following a vegan diet shows superb protection against disease in long term studies. Intermittent fasting has good-quality short term data available proving its efficacy against disease.

Based on the overall evidence; it’s an obvious assumption that vegan intermittent fasting is the gold standard for disease prevention. It’s an approach that combines both methodologies to achieve maximum results.

Metabolic Flexibility

Achieving metabolic flexibility has a downstream benefit of lowering blood glucose during your fasting periods. It allows the body to switch between burning glucose (carbohydrate) or fat for fuel.

Metabolic flexibility is often viewed as the holy grail of health by low-carb enthusiasts. Although not everybody in the vegan community subscribes to this method of thinking; it does raise some interesting points.

Training your body to effectively burn fat will allow for more consistent overall energy. Instead of having that afternoon carb crash and craving; you will seamlessly switch to fat burning mode to keep you going. This theory has made intermittent fasting increasingly popular with endurance athletes, many of whom are now choosing to train while fasting.

Vegans looking to become metabolically flexible will greatly benefit from intermittent fasting. It’s arguably the most effective way to improve your fat burning capability.


One of the biggest reasons intermittent fasting has hit the headlines is due to its proposed ability to extend lifespan. It’s been widely studied in animal models and has shown to be highly beneficial at improving longevity markers.

The science in this area is still ‘cutting edge’ and incredibly limited human data is available. It’s worth noting that cost and length of time for reliable studies are still a hurdle to cross. Additionally, the tools used to measure many of the proposed longevity markers are still in relative infancy.

The predominant ways that intermittent fasting has been shown to increase lifespan include improvements in oxidative stress, adaptivestress response and anti-aging cell activity. In addition, it’s thought to increase ‘autophagy’, which is the body’s process of clearing out damaged cells.

Vegan intermittent fasting is a great way to combine the longevity benefits of a shortened eating window with the proven health benefits of a plant-based diet. This combination of rejuvenation and disease prevention makes it a standout longevity strategy.

Additional benefits

  • Increased energy
  • Improved mood
  • Sharpened focus
  • Improved brain health
  • Increased growth hormone
  • Greater feeling of satiety
  • Tougher mental resilience
  • Improved sleep quality
  • Better time management
  • Starves bad bacteria
  • Promotes mindful eating
  • Greater appreciation for whole-foods
  • Decreased food bill
Vegan Smile
Vegan intermittent fasting promotes wellbeing

Potential pitfalls of vegan intermittent fasting

1. Unintended weight loss.

Vegans with a low BMI may find themselves underweight if they fail to consume enough calories during their ‘feeding’ time. Since plant-based foods are often low in calories but high in fiber; it can be difficult for some to consume adequate calories to maintain weight.

2. Binge eating.

It can be easy to overconsume calories and junk food during your feeding time because you’ve ‘earned it’. However, this can lead to weight gain, poor health outcomes and unhealthy eating habits.

3. Dizzy spells, headaches and nausea.

It’s common to have unwanted side effects during your fasting period, especially when you’re just starting out. The body’s reaction to being deprived of incoming food can often lead to dizziness, headaches and nausea.

Keep in mind that these symptoms are often temporary and will improve as your body adapts to a new eating schedule. However, if these feelings persist long-term, it could also mean that you’re chronically underfed.

4. Disordered eating.

Modifying your diet or eating pattern can lead to an unhealthy relationship with food. Some vegans may feel restricted by taking long periods of time away from eating, or take their fasting protocol too far and see adverse consequences.

5. Nutrient deficiency.

Eating less frequently could mean fewer opportunities to ingest the nutrients you need to maintain optimal health. Vegans that proceed to eat an unhealthy diet while intermittent fasting put themselves at risk of nutrient deficiency.

Anyone following intermittent fasting should aim to follow a whole-food plant-based diet that encompasses a variety of food groups. Look for nutrient density when loading up your plate and ensure you’re taking dietary supplements when necessary.

Vegan Salad
Putting plants on your plate will keep your nutrient levels high

Top tips to make vegan intermittent fasting easier

1. Eat real whole-foods.

Following a junk food vegan diet can leave you feeling lousy during your fasting period. In addition, it will put you at risk for malnutrition. It is nutrient dense whole-foods that will fuel your body and mind throughout the day.

2. Drink plenty of water.

It’s estimated that 20% of your daily fluid intake comes from food. When you’re not eating, it’s important to replace this with adequate water intake. Water can also give you a greater sense of satiety and help you stave off dehydration.

3. Accept periods of hunger.

Hunger is often a feeling that will come and go, especially when you’re new to fasting. In the beginning, it’s important to ride out hunger waves and allow them to pass. Over time, you will learn to recognize ‘true hunger’.

4. Eat the right balance of protein, fat and carbs.

Common vegan intermittent fasting mistakes include; eating too many fast digesting carbs, not ingesting adequate protein or eating unhealthy fats. Remember that slow-digesting foods will aid satiety and provide sustained energy throughout your fast.

5. Keep busy.

Sitting around thinking about eating all day isn’t going to set you up for a successful fast. Proceed to approach your day in a productive manner and you will often forget about food.

6. Don’t binge eat.

It’s easy to lose the benefits of fasting by piling your plate with unhealthy food. Keep your diet sensible during your ‘feeding’ time if you want to reap the rewards.

7. Find a sustainable fasting pattern.

Don’t jump into a challenging fasting plan if you’re not ready. Start with pattern that fits your schedule and allow your body time to adapt. Fasting will usually have an adaptation period and unnecessary suffering might force you to quit.

Intermittent fasting happy
Find an eating pattern that keeps you happy

Who should not intermittent fast?

You should not attempt vegan intermittent fasting if you fall into any of the following categories:

  • Underweight (often diagnosed as having a BMI less than 18.5)
  • Have an eating disorder
  • Pregnant
  • Currently breastfeeding
  • Under the age of 18
  • Diabetic (unless under doctor supervision)
  • Have a serious medical condition
  • Taking prescription medication (unless cleared with a doctor)
Empty plate intermittent fasting
Having an empty plate isn’t good for everyone

How to start intermittent fasting on a vegan diet

It’s common for vegans to feel overwhelmed when attempting their first intermittent fast. However, it’s important to stick to the basics and follow a lifestyle that suits your needs.

Follow the below steps to maximize your chances of success:

1. Find the right fasting pattern.

Most vegans start with the popular 16:8 diet. It will allow you to eat within an 8 hour window during the day (e.g. 11am-7pm). If this fits your schedule and physical needs, great; If not, choose a shorter fast (e.g. 14:10, 12:12) or a different type of fast.

Remember that there is no ‘one size fits all’ approach to intermittent fasting. Choose the schedule that works for you and adapt as necessary.

2. Plan your meals.

Be mindful of the foods you plan to eat when breaking your fast. Remember that you’re likely to be very hungry when it approaches feeding time and you don’t want to risk having a ‘food emergency’.

Preparing or planning your meals in advance is a great way to ensure healthy eating. If you know that your end of fast meal is already prepared in the fridge; you’re unlikely to find yourself eating junk food.

3. Be patient and expect hunger.

The body takes time to adapt when it feels ‘deprived’ of nutrition. You will likely feel fatigued, hungry or a bit lightheaded during your initial fasts. However, this is rarely cause for concern and these feelings should subside as your body adapts.

Make sure you’re implementing protocols to keep hunger at bay in order to smooth your transition into intermittent fasting. Drink plenty of water, keep busy and eat the right foods during your feeding window.

4. Review your progress.

It’s important to review your fasting schedule after a couple of weeks. Notice if you’re starting to adapt and feel less hungry. In addition, make sure your health markers are heading in the right direction.

If you’re losing too much weight; maybe you’re fasting too much. If your health is not improving as you expected; maybe you could fast slightly longer. The body is constantly evolving and we need to adapt to its requirements and listen to what it needs.

5. Connect with a community.

Surrounding yourself with a health conscious community can make fasting easier. Knowing that countless others are out in the world following the same protocol can make your journey a whole lot easier.

Follow the right folks on social media, read inspirational articles online and keep up-to-date with the latest science. You can always keep in touch with Plant Fuel Focus to get the motivation you need!

Vegan Intermittent Fasting Community
Connecting with other vegans can help your fasting goals

Thoughts from the author

Adopting a plant-based diet is probably the best decision you can make for your health. It’s a great way to prevent disease, improve vitality and feel like the best version of yourself on a daily basis. If you then want to further enhance these benefits; it might be time to try intermittent fasting.

My personal experience with a vegan intermittent fasting diet has been hugely beneficial. It’s enhanced my body composition, stabilized my mood and improved my health markers. I also have boundless energy and recover extremely fast after exercise. To be honest; I feel great.

Expect to run into a few hurdles during your initial fasts, but it should definitely get easier over time. Following the guidelines in this article should help you transition into your new protocol. The key for me was making sure I consumed enough calories, which could be a challenge for anyone whole-food plant-based.

The power of what you eat is huge, but sometimes when you choose to eat is just as important. Intermittent fasting is a powerful tool and using it in the right way can bring spectacular results.

Please note: This article is for information purposes only and should not be taken as medical advice. As with any change of diet or eating pattern; the advice of a doctor should be sought prior to starting.

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