4:3 Diet vs 5:2 vs 16:8 vs OMAD: Why the 3-Day Fasting Method Might Be Your Best Bet
Intermittent fasting (IF) has become one of the most popular approaches to health, weight management, and overall well-being. From enhancing mental clarity to simplifying meal planning, fasting appeals to a wide range of people for its flexibility and effectiveness.
But with so many different fasting methods available, it can be tricky to figure out which one is right for you. Should you try 16:8 fasting, where you eat during an 8-hour window daily? Or maybe OMAD (One Meal a Day) suits your lifestyle? What about the well-known 5:2 diet, which involves calorie restriction two days per week?
In this article, we’ll take a close look at a rising star in the fasting world — the 4:3 diet, sometimes called the 3-day fasting method. We’ll explain what it is, how it compares to other popular intermittent fasting styles, and why it might be a great fit for your lifestyle and goals.
What Is the 4:3 Diet?
The 4:3 diet is a flexible intermittent fasting method that involves:
Eating normally for 4 days per week.
Restricting calories to between 500 and 1,000 calories on 3 days of your choice.
These 3 low-calorie days can be consecutive or non-consecutive, depending on what works best for you.
Unlike daily time-restricted eating methods (which limit your eating hours each day), or OMAD (which compresses all daily calories into one meal), the 4:3 diet focuses on weekly calorie reduction through a set number of low-calorie days.
Because you get to eat normally most days, the 4:3 diet offers a powerful calorie deficit while maintaining flexibility and sustainability.
How Does 4:3 Compare to Other Popular Intermittent Fasting Methods?
Let’s break down the main differences between the 4:3 diet and other popular fasting approaches: 16:8, OMAD, and 5:2.
16:8 Fasting — Daily Time-Restricted Eating
The 16:8 method involves fasting for 16 hours every day and eating during an 8-hour window. For example, you might eat between 12 PM and 8 PM each day.
How it works: You consume all your daily calories during the 8-hour window and fast for the remaining 16 hours.
Food choices: You can eat any foods you want during the eating window, with no specific calorie restrictions.
Who it suits: People who prefer a daily routine and want to reduce snacking or late-night eating without counting calories.
Note: The 16:8 method controls when you eat, but not how much. This makes it a great option for some, but others may find it less effective for significant calorie control.
OMAD — One Meal a Day
OMAD condenses your entire day’s calorie intake into one meal, followed by roughly 23 hours of fasting.
How it works: You fast most of the day, then eat all your calories in a single meal, usually within a 1-hour eating window.
Food choices: As with other IF methods, you can choose any foods during your meal.
Who it suits: People who prefer a simple, minimal-meal routine and find longer fasting windows manageable.
OMAD can naturally reduce calorie intake due to the limited eating time, but it may feel restrictive for some.
5:2 Diet — Two Low-Calorie Days Weekly
The 5:2 diet involves eating normally 5 days a week, and restricting calories (typically 500–600) on 2 non-consecutive days.
How it works: Two fasting or very low-calorie days interspersed with five days of normal eating.
Food choices: No food restrictions other than calorie limits on fasting days.
Who it suits: Beginners to fasting or those seeking moderate calorie reduction without daily fasting.
4:3 Diet — Three Low-Calorie Days Weekly
The 4:3 diet builds on the 5:2 model by increasing low-calorie days to three per week.
How it works: Eat normally 4 days per week; restrict calories (500–1,000) on 3 chosen days.
Flexibility: You decide which days to fast; they can be consecutive or spread out.
Food choices: No specific food rules, just calorie limits on fasting days.
This method provides a larger weekly calorie deficit than 5:2 while maintaining the freedom to eat normally most days. It offers a balance between calorie control and lifestyle adaptability.
Why Choose the 4:3 Diet?
The 4:3 diet offers a unique blend of benefits:
Flexibility to Fit Your Life
With only 3 fasting days per week — which you can pick freely — the 4:3 diet is easy to integrate into various schedules, social lives, and work routines. No need to fast on fixed days, no strict eating windows — you decide.
Significant Weekly Calorie Reduction
Increasing fasting days from 2 (as in 5:2) to 3 creates a bigger calorie deficit over the week, helping to support steady fat loss without requiring daily fasting.
Freedom to Enjoy Your Favorite Foods
Because you eat normally on 4 days, and have no restrictions on what you eat on fasting days (only how much), the 4:3 diet allows for variety and enjoyment — no deprivation needed.
Sustainable Long Term
Many find the 4:3 diet easier to maintain than daily fasting methods or extreme calorie restriction, as it offers both structure and freedom. This balance makes it a sustainable lifestyle choice rather than a short-term diet.
Who Is the 4:3 Diet Best For?
People with busy, variable schedules: The flexibility to pick any 3 fasting days means it fits around social events, work, and family life.
Those wanting gradual, steady weight loss: The calorie reduction is effective but not extreme.
Anyone seeking balance: Eat normally most days, with planned calorie control on fasting days.
People who enjoy multiple meals per day: There’s no need to limit meals; just stay within your calorie targets on fasting days.
How to Get Started with the 4:3 Diet
Choose your fasting days: Pick 3 days per week that suit your schedule. They can be consecutive or spread out.
Set your calorie target: Aim for about 500–1,000 calories on fasting days.
Eat normally the other 4 days: No calorie restrictions, eat your usual meals.
Listen to your body: Adjust fasting days or calorie targets based on how you feel and your progress.
Stay hydrated: Drink plenty of water, herbal teas, or black coffee during fasting periods.
Final Thoughts
The 4:3 diet stands out among intermittent fasting methods for its flexible, manageable approach to calorie control. By allowing normal eating four days a week and structured calorie restriction on three days, it strikes a balance between effectiveness and lifestyle friendliness.
If you want a fasting plan that adapts to your life, not the other way around, and lets you enjoy food while working toward your goals, the 4:3 diet deserves serious consideration.