The 20:4 intermittent fasting diet (warrior diet) has recently skyrocketed into popularity. This diet is largely popular because many believe it’s the secret key to weight loss and reducing body fat.

Many adults in the United States use intermittent fasting, including the 20:4 method (warrior diet), as a weight loss tool. 

We’ve collated all the information you need to know to construct the ultimate beginner’s guide to the 20:4 intermittent fast, including the risks and benefits of the warrior diet and a simple warrior diet meal plan. 

What is the warrior diet? 

The warrior diet is also known as the 20:4 intermittent fasting diet. Fitness specialist, Ori Hofmekler, created the warrior diet back in 2001. Since then, this diet plan has gained immense popularity as many people promise that it’s one of the fastest ways to lose weight and see significant results. 

The warrior diet is a form of intermittent fasting, which essentially cycles between periods of eating and fasting. In the 20:4 intermittent fasting diet, people alternate between 20 hours of fasting and a 4-hour window of eating. Within that 4-hour eating window, they will consume their daily intake of calories. The goal of this diet is weight loss and body fat loss. 

fasting and window hours

Fasting is an old-age concept that has outlived numerous generations and lasted for centuries. And there’s nothing new about it. The warrior diet was constructed to mimic the lifestyle of warriors in the past, where they would hunt and scavenge for food in the day and have a big feast at night. Ultimately, this diet aims to improve our looks and health by putting our bodies through adversity and allowing our survival instincts to kick in. 

Warrior Diet

Does the warrior diet work? 

You may be keen on trying out the warrior diet to lose weight and body fats and maybe improve your overall health and wellbeing. However, the truth is, no concrete research has conclusively supported the benefits of this diet. In actual fact, Ori Hofmekler himself has declared that this diet was formulated based on his observations and conclusions and not based on fundamental research. 

While research studies have proven that intermittent fasting can lead to weight loss, many experts and health professionals believe that the 20:4 intermittent fasting plan is extreme. Hence, the warrior diet is not suitable for everyone

How much weight loss is possible with the warrior diet?

Everyone wants to know how much weight they can lose with the 20:4 intermittent fasting diet. Generally, numerous studies have associated intermittent fasting with weight loss. Hence, many believe that the warrior diet should lead to weight loss. 

For example, a particular study that is highly similar to the warrior diet and involves 20 hours of fasting discovered this. Participants who consumed calories within the 4-hour eating window in the evening experienced more weight loss than those who consumed the same amount of calories throughout the entire day. 

However, there’s more to the story than meets the eye. Another analysis revealed no significant difference in weight loss between those who fasted and those who restricted their calories without fasting. 

In short, calorie intake probably plays a massive role in weight loss. If you consume an astronomical amount of calories during the 4-hour eating window, weight loss will be an unlikely result. Some people who consume excessive calories or binge eat during that feasting window end up gaining weight. 

Warrior Diet

What can I eat during the warrior diet? 

You may have this question looming in your mind, “How many calories can I consume during the warrior diet?” 

While you may automatically associate fasting with limiting calorie consumption to promote weight loss, the warrior diet is a little different. 

During the 20 hours of fasting, you are encouraged to eat a tiny portion of food. In other words, you should undereat during this period. Some foods you may consume include cottage cheese, hard-boiled eggs, raw veggies, fruits, yoghurt, vegetable juices, and other fluids with low to no calories. 

When you are allowed to break your fast, you can eat any foods you wish during the 4-hour eating window. There are no restrictions and zero calorie targets or limits, so many people end up binge eating. During this period, it’s best to stick to nutrient-dense and healthy foods as much as possible. 

Warrior Diet Meal Plan Checklist

Here’s a quick and easy checklist to help you formulate your warrior diet (20:4 intermittent fasting) meal plan.

Foods you should eat in small quantities during the undereating phase

  • Dairy including cottage cheese, yoghurt, and milk 
  • Raw vegetables and fruits including green veggies, carrots, mushrooms, onions, apples, pineapple, kiwi, and mangoes
  • Hard-boiled eggs
  • Broth 
  • Vegetable juices, 
  • You can drink water, coffee, or tea throughout the day (not necessarily in small portions)

Foods you should eat during the 4-hour eating window:

  • Proteins such as chicken, beef, fish, and eggs
  • Dairy including cheese, milk, and yoghurt
  • Healthier fats such as nuts and olive oil 
  • Whole-grain foods including quinoa, pasta, rice, and oatmeal 
  • Fruits and cooked vegetables 

Foods you should avoid as much as possible during the warrior diet: 

  • Sugary drinks and foods including donuts, cookies, and cakes
  • Fast foods, deep-fried foods and junk food
  • Processed meats/ high-sodium foods (such as salami and bacon)
  • Artificial sweeteners 

Will a 20-hour fast put me in ketosis? 

Fasting or not consuming any food can help someone attain ketosis. Generally, people enter ketosis after consuming less than 50 grams of carbohydrates daily for 2-4 days. However, this may vary from person to person. 

However, say you wish to fast for more than a few hours at one time, and this includes the warrior diet. In that case, you should consult your healthcare professional beforehand to determine if this diet is safe for you and if the pros outweigh the cons. 

consult your health professional

What are the health benefits of the warrior diet? 

Some benefits of the warrior diet may include weight loss, improved blood sugar control and insulin resistance, enhanced cognitive (brain) function, and reduced inflammation. However, further studies are needed to confirm these benefits concretely. 

What is a good meal plan for the warrior diet? 

Here is a warrior diet meal plan you may wish to follow. However, keep in mind that it is crucial you consult your healthcare provider before attempting this diet plan. 

Week 1

  • Try to undereat from the time you awake in the morning until your evening meal. 
  • During the 20-hour fasting window: You should consume small portions of dairy products, hard-boiled eggs, raw vegetables and fruits, and broth. In addition to that, you may drink water, coffee, or tea with no added sugar throughout the day. 
  • During the 4-hour eating window: It’s best to eat your first serving and then take a 20-minute break. This helps prevent overeating. You may have salads with a small amount of olive oil and vinegar as dressing, wheat-free whole grains, beans, cheese, yoghurt, poached or hard-boiled eggs, and steamed vegetables. 
  • During week 1, try your best to steer clear of sugary foods and drinks as well as artificial sweeteners. 

Week 2

  • Week 2 is the ‘high fat’ phase. 
  • During the 20-hour fasting window, eat the same types of foods as week 1. 
  • People should eat a handful of nuts at night during this phase. 
  • At night, during the eating window, you may have the same types of foods as week 1, but replace the beans with lean animal proteins, fish, and eggs, and leave out the grains/starches. 
  • Consume the nuts first, and if you are too full to eat the proteins, you may wish to leave it out. The priority is given to the handful of nuts. 
  • During this phase, try not to consume any grains or starches. 

Week 3

The third week cycles between high-carb days and high-protein days. For example: 

  • 1 or 2 days: High-carb foods
  • 1 or 2 days: High protein foods and low carbs
  • 1 or 2 days: High-carb foods
  • 1 or 2 days: High protein foods and low carbs

The foods for the 20-hour undereating phase remain the same as week 1 and week 2. 

On high-protein days, you may have a salad and 8-16 ounces of animal proteins. Try to incorporate non-starchy and cooked vegetables, too. 

On high-carb days, have a salad, some cooked vegetables, a small serving of animal proteins, and one main carbohydrate per meal. You may choose higher-carb foods such as sweet potatoes, rice, quinoa, oats, pumpkin, or peas for the primary carb. 

Warrior Diet

Week 3 onwards 

From week 3 onwards, you can rotate between those phases. Because everyone’s body is different, try to plan those phases according to your needs. If you have any doubts about this, you may wish to consult your doctor or nutritionist. 

Ori Hofmekler also advises people to stack up on their nutritional needs by consuming supplements such as probiotics, multivitamins, and amino acids. As with any supplement, seeking professional advice before commencing them is the safest route to go! 

What are some good beginner tips for the warrior diet? 

If you’re searching for a beginner’s guide to the warrior diet, you may wish to keep these tips in mind. Admittedly, intermittent fasting can prove to be a challenge, especially when temptation comes knocking at your window. Furthermore, the warrior diet is considered one of the more extreme forms of dieting in comparison to less strict intermittent fasting methods such as the 16:8 fast. 

However, with these tips in mind, you may be able to boost your chances of success. 

  • Seek qualified advice from your healthcare provider. If they determine that this method is safe and suitable for you, they may be able to provide you with guidelines on how you can safely and effectively carry it out. 
  • Set your goals and seek support from trusted friends and family. Knowing your baseline measurements, such as your initial weight (if weight loss is your goal), may help you determine if this method works effectively for you. 
  • Don’t expect overnight success. Having unrealistic expectations sets you up for failure and disappointment. 
  • Stay hydrated with low or no-calorie fluids, and most importantly, water. 
  • Avoid beer or alcoholic beverages. 
  • Don’t place yourself in a position where you will be significantly tempted during the 20-hour undereating phase. For example, don’t go strutting into your favourite fast-food restaurant. The enticing aroma of delicious food may leave your willpower and determination shattered. 
  • Don’t overexert yourself. If you notice any worrying signs (further explained below), seek medical advice as soon as you can. This diet may not be appropriate for you. 
  • Don’t beat yourself up over failure. Say you find that this method of fasting is too much for you to handle. In that case, you may wish to consider another form of intermittent fasting that is less strict, such as the 16:8 or 5:2 diet
Warrior Diet

What are the risks of the warrior diet? 

You may be wondering, ‘How much fasting is too much?’ 

Well, the warrior diet can lead to side effects such as:-

  • Fatigue and lack of energy 
  • Insomnia
  • Dizziness or lightheadedness
  • Hypoglycemia (low blood sugar) 
  • Extreme hunger
  • Fainting 
  • Irritability or anxiety 
  • Lack of nutrition 
  • Hormonal imbalance
  • Weight gain (due to binge eating or overeating) 

If you experience any of these symptoms and they concern you, you may be fasting too much. The warrior diet, or intermittent fasting in general, is not appropriate for everyone. To ensure you get sufficient calories and nutrients, try to incorporate healthy and nutrient-dense foods into your daily meals. 

Additionally, the warrior diet may lead to disordered eating patterns, such as binge eating. Often, binge eating is associated with self-hate, shame, and guilt, which can negatively and severely impact an individual’s mental health.

What are some precautions? 

The warrior diet or 20:4 intermittent fasting diet is not suitable for everybody. Some people who should not try this diet include:-

  • Pregnant and breastfeeding women
  • People with certain medical conditions such as Type 1 diabetes
  • Children
  • Those who are underweight 
  • People with eating disorders and a history of eating disorders or disordered eating patterns. 
Warrior Diet

Bottomline: Warrior Diet

Many believe that this wildly popular diet can lead to weight loss and body fat reduction. But take everything with a grain of salt. 

This form of intermittent fasting may benefit some people but may pose a threat to some others. So before trying out any form of intermittent fasting, it’s always best to seek professional advice.

Disclaimer: This article is only a guide. It does not substitute the advice given by your own healthcare professional. Before making any health-related decision, consult your healthcare professional.

Editorial References And Fact-Checking
  • Capritto, A. (2021). What Is the Warrior Diet?. Retrieved from
  • Dong, T. A., Sandesara, P. B., Dhindsa, D. S., Mehta, A., Arneson, L. C., Dollar, A. L., . . . Sperling, L. S. (2020). Intermittent Fasting: A Heart Healthy Dietary Pattern? Am J Med, 133(8), 901-907. doi:10.1016/j.amjmed.2020.03.030
  • Harris, L., Hamilton, S., Azevedo, L. B., Olajide, J., De Brún, C., Waller, G., . . . Ells, L. (2018). Intermittent fasting interventions for treatment of overweight and obesity in adults: a systematic review and meta-analysis. JBI Database System Rev Implement Rep, 16(2), 507-547. doi:10.11124/jbisrir-2016-003248
  • Kubala, J. (2018). The Warrior Diet: Review and Beginner’s Guide. Retrieved from
  • Richards, L. (2020). Everything to know about The Warrior Diet. Retrieved from
  • Stote, K. S., Baer, D. J., Spears, K., Paul, D. R., Harris, G. K., Rumpler, W. V., . . . Mattson, M. P. (2007). A controlled trial of reduced meal frequency without caloric restriction in healthy, normal-weight, middle-aged adults. Am J Clin Nutr, 85(4), 981-988. doi:10.1093/ajcn/85.4.981
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Jasmine Chiam, B.Pharm

Jasmine is a Bachelor of Pharmacy graduate from Monash University. She started off as a freelance writer for various medical companies, startups, and wellness organizations in the health and medical field. Now, she manages HealthPlugged’s entire content team. LinkedIn


  • Jasmine is a Bachelor of Pharmacy graduate from Monash University. She started off as a freelance writer for various medical companies, startups, and wellness organizations in the health and medical field. Now, she manages HealthPlugged’s entire content team. LinkedIn


Jasmine is a Bachelor of Pharmacy graduate from Monash University. She started off as a freelance writer for various medical companies, startups, and wellness organizations in the health and medical field. Now, she manages HealthPlugged’s entire content team. LinkedIn