How Long Does it take for Intermittent Fasting to Work?

Intermittent fasting is one of the inexpensive and effective ways to speed up weight loss and improve overall fitness. A systematic review of 40 studies has shown that intermittent fasting is effective for weight loss and takes approximately three months to shed 7-11 pounds. 1Diet Review: Intermittent Fasting for Weight Loss

However, the research was done on diverse people, including lean vs. obese, and from 2 to 104 weeks duration. So it won’t be a practical answer to your question about how long does it take for intermittent fasting to work?

I have broken down the answers into two parts so you can easily understand them. I’ve also included some practical tips in this article to help maximize your results.

But before we move further, let’s understand what IF is and how it works.

What is Intermittent Fasting and How How Does it Work?

How Long Does Intermittent Fasting Take To Lose Weight?

Intermittent fasting is also known as window fasting. It’s an eating pattern that cycles between periods of fasting and eating. It has various patterns, such as 16/8, 14/10, and 12/12, and each pattern tells you when you should eat and fast. However, it doesn’t specify which foods to

eat or avoid during and after the fasting period.

Intermittent fasting works in several ways to improve your health. For example,

  • The IF restricts your calorie consumption and helps you stay in a calorie deficit which ultimately helps you lose weight over time. 2Welton S, Minty R, O’Driscoll T, Willms H, Poirier D, Madden S, Kelly L. Intermittent fasting and weight loss: Systematic review. Can Fam Physician. 2020 Feb;66(2):117-125. PMID: 32060194; PMCID: PMC7021351.
  • Intermittent fasting reduces insulin levels which is one of the major reasons for cardiovascular disease.3 Ingelsson E, Sundström J, Arnlöv J, Zethelius B, Lind L. Insulin resistance and risk of congestive heart failure. JAMA. 2005 Jul 20;294(3):334-41. doi: 10.1001/jama.294.3.334. PMID: 16030278.
  • The 18/6 IF schedule can trigger a metabolic switch from glucose-based to ketone-based energy, reduce stress, help you live longer, and decrease the incidence of health-related issues, including cancer and obesity – suggested in an article published by the New England Journey of Medicine.4 Effects of Intermittent Fasting on Health, Aging, and Disease by Rafael de Cabo, Ph.D., and Mark P. Mattson, Ph.D

You can check out this comprehensive analysis on the National Institute of Health website to learn more about it.

How Long Does it take for Intermittent Fasting to Work?

How long does it take for intermittent fasting to work

A collection of 40 studies have shown that intermittent fasting takes nearly 12 weeks to reduce 7-11 pounds when it comes to losing weight.

Another study has shown that 5/2 intermittent fasting decreases 3.7 kg of body fat over the period of 3 months in overweight people whose BMI was more than 25.5Current Evidence for IMF as a Weight-Loss Strategy: Evidence from Humans? Clinical Studies – Nutrients. 2019 Oct 14;11(10):2442. doi: 10.3390/nu11102442. PMID: 31614992; PMCID: PMC6836017

Twenty-seven more trials showed intermittent fasting decreased body weight by 0.8 % to 13 % over the period of 2 to 26 weeks.

Many studies concluded that one must follow 8 to 12 weeks of time-restricted fasting before seeing positive results on overall health like metabolic health, mood, brain health, etc.

However, the result varies from person to person. Some people only do interval fasting but don’t follow a restricted diet. Most people work out along with fasting. And some do all three, like fasting, diet, and exercising.

The proper you follow the routine, the faster you’ll see the results and vice versa.

Related: Intermittent Fasting Results In 1 Month- My Experience

The Best Intermittent pattern You can Follow

The intermittent fasting pattern is divided into two parts, fasting and eating window. There are several IF patterns like 16/8, 18/6, 5/2, and 14/10. Depending on your lifestyle, you can follow the one that suits you to your lifestyle.

  • 16:8 – 16 hours fast, 8 hours eating window.
  • 18:6 – 18 hours fast, 6 hours eating window
  • 14:10 – 14 hours fast, 10 hours eating window
  • 5:2 – 24-hour fast, 2 days a week

Following an intermittent fasting schedule consistently isn’t easy, and even it can be more challenging if you’re starting out. To help you get started, I have gathered a list of the best free books that you can download free of cost.

The Best Ways to maximize Intermittent Fasting Results

It is a growing trend that’s easy to understand but sometimes hard to perform. But you can follow some practical ways to maximize your results with intermittent fasting.

  1. Eat the right food: When you eat, it’s important to eat the right food. If you want to maximize your results, eat fiber-rich and protein-rich foods with low carbs and fats, for example, fruits, vegetables, beans, chicken breast, seafood, egg white, salmon, and lentils. Avoid sugary and processed foods as much as possible. (Related:
  2. Exercise frequently: You can exercise at any time of the day, from 15 minutes to 1 hour. Working out during the fasted state is challenging, but you can do yoga or cardio exercises to accelerate your metabolism and calories burning process. You can also do weightlifting in your feeding state to maximize your results.
  3. Stay hydrated: Drink plenty of water to keep yourself hydrated.
  4. Avoid eating calories at night-time or early morning: If you want to see the early results.
  5. Stick to a good sleep schedule: Try to get at least 7 hours of sleep every day. And set your routine of going to bed and waking up around the same time every day.

The Takeaway

How Long Does it take for Intermittent Fasting to Work? It takes 12 weeks to see results through the 16/8 and 18/6 fasting schedules.

Indeed intermittent fasting is an excellent way to speed up weight loss and improve overall fitness. You can lose weight through time-restricted fasting if you follow it consistently over time. However, every weight loss technique primarily focuses on calorie management and macros, so if you consume more calories than your body burns throughout the day, you’ll not lose weight.

Intermittent fasting isn’t for everyone, primarily underweight, under 18 years of age, pregnant or breastfeeding women, and people on medication.

The IF is easy to understand but sometimes hard to perform, and it can be even more challenging if you’re a newbie. So it would be best to get a proper guide to get started, and for that, you can download a free book or buy it from somewhere.

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Murshid Akram
I'm an online personal trainer, fitness blogger, and fitness enthusiast. I love researching and writing about exercise and nutrition. I share science-based, practical, and logical information that can help you achieve your desired fitness goal.

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