5:2 Diet: Complete Step-By-Step Guide for Beginners

The 5:2 diet, a form of intermittent fasting, became popular for its potential to aid weight loss and improve overall health. In this comprehensive guide, you will learn all the details of the 5:2 diet, covering its definition, how it works, pros and cons, meal plans, and more to help you see if this diet is for you.

Key Takeaways:

• On the 5:2 diet, you eat normally 5 days and one small meal on 2 days of the week.
• It benefits weight loss, longevity, metabolism, and heart health.
• The diet needs an adjustment period, increases hunger, and is not for everyone.

Table of Contents:

• What Is the 5:2 Diet?
• How Does the 5:2 Diet Work?
• Pros and Cons of the 5:2 Diet
• How to Eat on the Fast Diet
• Example Meal Plan
• Who Should Avoid the 5:2 Diet?
• My Experience
• Frequently Asked Questions
• References

What Is the 5:2 Diet?

The 5:2 diet, also known as the Fast Diet, is intermittent fasting involving eating normally for five days and “fasting” two days a week.

It gained popularity through the book “The Fast Diet” by Dr. Michael Mosley and Mimi Spencer.

In 2012, the book introduced the concept of intermittent fasting and the potential health benefits associated with calorie restriction on two non-consecutive or consecutive days of the week, depending on your preference.

The primary aim of the 5:2 diet is to promote weight loss and improve overall health¹ through intermittent fasting, with expectations of losing up to 1 lb per week among women. However, unlike traditional diets focusing on daily calorie restriction, the 5:2 diet adopts a unique approach by incorporating short periods of significant calorie reduction.

How Does the 5:2 Diet Work?

On fasting days, individuals typically restrict their calorie intake to a quarter of their usual amount, usually around 500-600 calories. Experts believe this temporary calorie reduction triggers a metabolic response that promotes weight loss and enhances overall health.

How to Do the 5:2 Diet:

• Choose Fasting Days: Select two non-consecutive days of the week for fasting. Most people choose Mondays and Thursdays, but individuals can adjust based on personal preference and schedule.
• Calorie Restriction on Fasting Days: On fasting days, aim to consume approximately 500-600 calories, about a quarter of your daily calorie needs. Focus on nutrient-dense foods such as lean proteins, vegetables, and small portions of whole grains. Again, you are free to choose what you eat or adjust the calorie restriction to a much lower number, especially if you’ve fasted in the past.
• Regular Eating on Non-Fasting Days: Maintaining a balanced diet for the remaining five days of the week. There are no specific restrictions, but keep a healthy and well-rounded approach to nutrition in mind. Reducing carbs supports the benefits of intermittent fasting.

Different Approaches to the 5:2 Diet:

• Modified Fasting: Some individuals choose a modified approach, consuming a much-reduced calorie intake rather than doing a complete fast on fasting days. This could involve eating a small meal or dividing the calories into multiple small snacks throughout the day. However, it’s important to remember that taking food, regardless of how little it is, affects the body’s fasting rate, metabolism, and autophagy.
• Variations in Fasting Days: While Mondays and Thursdays are common fasting days, individuals may choose different days based on their schedules and preferences. Flexibility in selecting fasting days contributes to the adaptability of the 5:2 diet.

Pros and Cons of the 5:2 Diet

Before diving into the pros and cons, it’s important to note that individual responses to the 5:2 diet can vary. You should consider these pros and cons based on your health, preferences, and lifestyle. Also, consult with a healthcare professional before making significant changes to your diet, especially if you have underlying health conditions.

Pros:

1. Weight Loss: A handful of studies back the effects of intermittent fasting, including the 5:2 diet, against obesity and weight loss. A study published in the American Journal of Clinical Nutrition² found that intermittent fasting, including the 5:2 approach, can lead to significant weight loss. Another study³ claims that intermittent fasting shows promise for the treatment of obesity.
2. Metabolic Health: Research suggests intermittent fasting may improve metabolic health⁴ by enhancing insulin sensitivity and lipid profile. Improved insulin sensitivity is particularly relevant for individuals at risk of type 2 diabetes.
3. Heart Health: Studies, both pre-clinical and clinical, have shown that there are several advantages to intermittent fasting⁴ for treating a variety of conditions aside from diabetes and obesity, including hypertension and cardiovascular risk factors.
4. Cellular Repair and Longevity: Studies in animals suggest that intermittent fasting may trigger cellular repair processes⁵ and contribute to longevity. A growing body of research also indicates that calorie restriction or intermittent fasting may trigger adaptive autophagy,⁶ extending the lifespan of eukaryotic cells. However, note that sustained calorie restriction that triggers an overabundance of autophagy is detrimental and can cause type II autophagic cell death.
5. Simplicity and Flexibility: While not a direct scientific benefit, the simplicity and flexibility of the 5:2 diet may contribute to its adherence. It’s also important to note that there is evidence that the 5:2 diet does not create conflict with other health-related behaviors.⁷ This only means that the 5:2 diet is pretty reliable and safe for beginners.

Cons:

1. Increased Hunger: Fasting days on the 5:2 diet may lead to increased hunger, especially when new to it. However, hunger levels tend to decrease over time as the body adapts to the fasting routine.
2. Nutrient Intake Concerns: On fasting days, there is a risk of not meeting daily nutrient requirements. A comprehensive data analysis⁸ states that the diet 5:2 was low in carbohydrates, moderate in fat, high in protein, and low in fiber. While they mentioned that the consumption of several micronutrients is lower than advised, all things considered, the 5:2 diet is a safe and effective weight-loss diet plan.
3. Initial Adjustment Period: The initial stages of intermittent fasting, including the 5:2 diet, may be challenging for some individuals. However, a comprehensive study suggests that people who have been doing intermittent fasting for three months have increased quality of life and decreased fatigue.⁹
4. Not Suitable for Everyone: Certain populations, such as individuals with diabetes, may need careful consideration before adopting the 5:2 diet. Intermittent fasting may affect blood glucose levels,¹⁰ and individuals with diabetes should consult with healthcare professionals before starting such regimens.
5. Limited Long-Term Data: While short-term studies support the potential benefits of the 5:2 diet, there is limited long-term data. Long-term adherence and its effects on health outcomes require further investigation.

How to Eat on the Fast Diet

The key is remembering that you only need ¼ of your regular daily caloric intake when you’re on your fasting days. Here’s a quick overview of what you can eat during the 5:2 diet.

Fasting Days:

On fasting days, focus on nutrient-dense, low-calorie foods. Opt for lean proteins, such as chicken or tofu, plenty of vegetables, and small portions of whole grains. Consider incorporating foods that help curb hunger, such as eggs, soups, and berries. Stay hydrated by drinking plenty of water, and consider black coffee for a metabolism boost.

Regular Days:

Typical days should include a balanced diet with various foods that will total your required daily calorie intake (2,000 for women and 2,500 for men). Ensure an adequate intake of essential nutrients, including lean proteins, vegetables, and whole grains. Keep an eye on portion sizes to maintain overall calorie balance.

Example Meal Plan

Getting into keto-friendly meals is a good idea since the diet mimics fasting and boosts its results. So, better skimp on pasta, oats, and beans and replace them with healthy fats.

Find breakfast, lunch, or dinner ideas that suit your liking:

Day	Breakfast	Lunch	Snack	Dinner	Total Calories (Estimate)
Monday	Scrambled eggs with spinach (150g): 150 calories	Grilled chicken breast (150g) with mixed vegetables (broccoli, bell peppers): 250 calories		Vegetable soup (300ml) with a side of mixed berries (100g): 200 calories	600
Tuesday	Greek yogurt with berries: 400 calories	Salad with mixed greens, cherry tomatoes, cucumber, and grilled salmon (150g): 600 calories	Avocado slices with salt and spices: 200 calories	Stir-fried tofu with broccoli and brown rice: 600 calories	1800
Wednesday	Keto egg muffins and scrambled eggs: 500 calories	Chicken Caesar salad with romaine lettuce, grilled chicken breast (150g), cherry tomatoes, and Caesar dressing: 600 calories	Greek yogurt with honey and almonds: 200 calories	Tuna, avocado, and quinoa salad: 700 calories	2000
Thursday	Berry smoothie with protein powder: 200 calories	Lentil soup (300ml) with a side of raw vegetables (carrot sticks, cucumber): 150 calories		Baked cod (150g) with steamed asparagus: 250 calories	600
Friday	Asparagus with Egg and Cheese Sauce: 350 calories	Turkey and avocado wrap with keto tortilla: 750 calories	Mixed nuts: 200 calories	Baked chicken breast (150g) with steamed broccoli: 700 calories	2000
Saturday	Chia seed pudding made with almond milk and topped with raspberries: 400 calories	Spinach, Strawberry, and Chicken Salad: 500 calories	Greek yogurt with mixed berries: 200 calories	Chicken meatballs with quinoa & curried cauliflower: 700 calories	1800
Sunday	Sausage and spinach skillet: 300 calories	Salmon rice bowl with cucumber: 500 calories	Greek yogurt with berries and nuts: 300 calories	Chicken with broccoli, beets, and farro salad: 700 calories	1800

Disclaimer: The calorie count on each meal will vary depending on your desired serving size and choice of ingredients.

Who Should Avoid the 5:2 Diet?

• Pregnant and lactating women
• Children
• Teens under 18
• People with diabetes
• People with GERD
• People with kidney problems
• People with a history of eating disorders

While the 5:2 diet is suitable for many, it may not be appropriate for everyone. The above-listed individuals should consult a nutritionist or physician before getting into the 5:2 diet or any type of intermittent fasting.

My Experience

The 5:2 diet can be viable for some individuals seeking weight loss and potential metabolic benefits. However, its suitability depends on individual factors and may not be appropriate for everyone. As with any diet, the key is to approach it with an understanding of personal health needs, preferences, and lifestyle.

If you are more experienced in intermittent fasting, you can try doing a total fast on the fasting days to avoid increasing your insulin levels. Moreover, the hunger hormone, ghrelin, decreases when your stomach is empty, so you will not feel hungry when you fast.

My experience is that it’s critical not to use eating days to “treat” yourself. Staying low in carbs will boost your results since fasting also burns fat through ketosis. Hence, a keto diet is the ideal match.

Before starting the 5:2 diet or any intermittent fasting regimen, seeking guidance from a healthcare professional or registered dietitian is recommended for a safe and personalized approach to nutrition.

Frequently Asked Questions

References

¹ Wang, Y., & Wu, R. (2022). The Effect of Fasting on Human Metabolism and Psychological Health. Disease Markers, 2022. https://doi.org/10.1155/2022/5653739

² Horne, B. D., Muhlestein, J. B., & Anderson, J. L. (2015). Health effects of intermittent fasting: hormesis or harm? A systematic review. The American journal of clinical nutrition, 102(2), 464-470.

³ Welton, S., Minty, R., Willms, H., Poirier, D., Madden, S., & Kelly, L. (2020). Intermittent fasting and weight loss: Systematic review. Canadian Family Physician, 66(2), 117-125. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7021351/

⁴ Vasim, I., Majeed, C. N., & DeBoer, M. D. (2022). Intermittent Fasting and Metabolic Health. Nutrients, 14(3). https://doi.org/10.3390/nu14030631

⁵ Longo, V. D., & Mattson, M. P. (2014). Fasting: Molecular Mechanisms and Clinical Applications. Cell Metabolism, 19(2), 181. https://doi.org/10.1016/j.cmet.2013.12.008

⁶ Shabkhizan, R., Haiaty, S., Moslehian, M. S., Bazmani, A., Sadeghsoltani, F., Bagheri, H. S., Rahbarghazi, R., & Sakhinia, E. (2023). The Beneficial and Adverse Effects of Autophagic Response to Caloric Restriction and Fasting. Advances in Nutrition, 14(5), 1211-1225. https://doi.org/10.1016/j.advnut.2023.07.006

⁷ Hajek, P., Przulj, D., Pesola, F., McRobbie, H., Peerbux, S., Phillips-Waller, A., Bisal, N., & Smith, K. M. (2021). A randomised controlled trial of the 5:2 diet. PLoS ONE, 16(11). https://doi.org/10.1371/journal.pone.0258853

⁸ Scholtens, E., Krebs, J., Corley, B., & Hall, R. (2020). Intermittent fasting 5:2 diet: What is the macronutrient and micronutrient intake and composition? Clinical Nutrition, 39(11), 3354-3360. https://doi.org/10.1016/j.clnu.2020.02.022

⁹ Anic, K., Schmidt, M. W., Furtado, L., Weidenbach, L., Battista, M. J., Schmidt, M., Schwab, R., Brenner, W., Ruckes, C., Lotz, J., Lackner, K. J., Hasenburg, A., & Hasenburg, A. (2022). Intermittent Fasting—Short- and Long-Term Quality of Life, Fatigue, and Safety in Healthy Volunteers: A Prospective, Clinical Trial. Nutrients, 14(19). https://doi.org/10.3390/nu14194216

¹⁰ Warner, S. O., Dai, Y., Sheanon, N., Yao, M. V., Cason, R. L., Arbabi, S., Patel, S. B., Lindquist, D., & Winnick, J. J. (2023). Short-term fasting lowers glucagon levels under euglycemic and hypoglycemic conditions in healthy humans. JCI Insight, 8(12). https://doi.org/10.1172/jci.insight.169789