Blog Diets Fasting How Long Does  It Take for Intermittent Fasting to Work?

How Long Does  It Take for Intermittent Fasting to Work?

Intermittent fasting (IF) is performed for many purposes. It can be a powerful tool for weight loss, metabolic health improvement, and disease prevention. It has also been claimed to enhance brain function, reduce inflammation, and increase longevity (2).

So when you start out, you’re naturally curious – how long should you expect before noticing changes? Will you get the results you hope for?

As with most healthy and sustainable lifestyle changes, IF isn’t a quick fix. It requires patience, consistency, and time to allow your body to adjust and start reaping the benefits. However, this doesn’t mean that you’ll need to wait forever to see progress.

Here’s a more detailed look at what you can expect and when with intermittent fasting.

What Can the Benefits of Intermittent Fasting Be?

Intermittent fasting has many potential benefits and weight loss (which is generally the primary goal) is just one of them. As fasting puts you in a calorie deficit, it can help you shed excess fat. But that’s not the only potential perk – here are some more:

Improved Metabolic Health

Metabolic health refers to how well your body processes and uses energy. When you fast, your insulin levels drop, which allows your cells to become more sensitive to this hormone. This makes it easier for them to absorb glucose from the blood when required(4).

As a result, intermittent fasting may be beneficial for conditions relating to insulin resistance such as type 2 diabetes. It may also reduce the risk of heart disease, cancer, and Alzheimer’s (4). If you have diabetes or impaired glucose tolerance, you should speak with your healthcare provider before starting intermittent fasting. 

See also
16/8 Intermittent Fasting for Seniors: Benefits, Meal Plans, and Tips

Increased Autophagy

Autophagy is the process of cellular self-cleaning and removing damaged or dysfunctional components. It’s essential for maintaining cell health and preventing disease development. Fasting is believed to promote autophagy, so intermittent fasting may help keep your cells in top shape (5).

Lower Inflammation Levels

Chronic inflammation is linked to a variety of health issues such as obesity, heart disease, and autoimmune disorders. Fasting may reduce inflammation by lowering oxidative stress and promoting weight loss (2).

Better Brain Function

Intermittent fasting may also have a positive impact on brain function. It has been proven to increase the production of brain-derived neurotrophic factor (BDNF), a protein that promotes the growth of new brain cells (2). This may improve cognitive function and mood, and even protect against neurodegenerative diseases.

Longer Lifespan

Studies on animals have shown that calorie restriction can increase longevity by as much as 30%. While more research is required in humans, some studies have hypothesized an association between IF and longevity (2).

Intense sweat sessions, working weight loss tips, lip-smacking recipes come in one package with the BetterMe app. And all of it is at your fingertips, start transforming your life now!

See also
10 Intermittent Fasting Mistakes People Make And How To Avoid Them

How Long Does Intermittent Fasting Take to Show Results?

Intermittent fasting typically takes at least a month before you see results, but this can vary depending on individual factors such as age, gender, lifestyle, and starting weight. Here’s a general timeline of what you can expect:

Week 1-2: Adjusting to Fasting

During the first week or two of intermittent fasting, many people experience hunger pangs, cravings, and irritability. This is because your body is used to getting food regularly and it takes some time to adapt to the new eating pattern.

Week 3-4: Changes Start Appearing

By week three or four, your body should have adjusted to fasting. At this point, you may start to notice physical changes such as weight loss and improved energy levels. Your clothes may also feel looser.

In addition to visible changes, there’s plenty happening in your body at the cellular level. At the one-month mark, you could be experiencing:

Better insulin sensitivity – this means that your body needs less insulin to regulate blood sugar levels (4).

Decreased triglycerides, and LDL and VLDL cholesterol – triglycerides are fats that can accumulate in your blood and increase the risk of heart disease. LDL is “bad” cholesterol that can also contribute to heart problems and VLDL is a type of cholesterol that carries fat from the liver to other parts of your body (6).

See also
The Simplest Intermittent Fasting Guide of 2023

Better appetite regulation –  fasting does not appear to cause the same increase in appetite that tends to come with continuous energy restriction (10).

Improved blood pressure and heart rate – your blood pressure may decrease, a potential sign of improving cardiovascular health and/or weight loss (8).

Improved mood and mental clarity – many people have reported improvements in their mood, focus, and productivity when they follow intermittent fasting (2).

Read more: What Can I Eat During Intermittent Fasting?

how long does it take for intermittent fasting to work  

Week 8 (2 months in): More Significant Changes

Following 2 months of intermittent fasting, you may see more significant changes, including:

Lower inflammation – C-reactive protein (CRP) is a marker of inflammation and is linked to various diseases. Some types of intermittent fasting have been found to reduce CRP levels with a certain level of weight loss (3).

Better athletic performance – athletes may experience improved endurance, strength, and power due to increased energy efficiency (7).

More fat loss – after 2 months, you may have created an overall calorie deficit for long enough to experience significant fat loss (2).

More beneficial gut bacteria – fasting may promote the growth of good bacteria in the gut, which leads to better digestion and overall health (6).

Week 12 (3 months in): Continued Progress and Maintenance

After 3 months of intermittent fasting, you may have achieved your initial weight loss goals or seen other health improvements. To continue seeing progress and maintain results, it’s essential that you stick with the fasting routine. You may notice:

See also
How Your Fasting Windows Can Make Or Break Your Intermittent Fasting Experience

Reduced cravings and improved food choices – as your body becomes more adapted, you may experience fewer intense cravings for unhealthy foods, which will lead to you making better food choices (10).

More muscle mass – intermittent fasting with exercise has been found to help preserve muscle mass while burning fat (9). As a result, you may have more defined muscles after 3 months.

Gut healing – by this point, your gut microbiome composition may have significantly changed, potentially resulting in better digestion and absorption of nutrients (6).

More consistent energy levels – with stable blood sugar levels and increased fat burning, you may have more sustained energy throughout the day (4).

Improved overall health markers – after 3 months of intermittent fasting, your insulin sensitivity, cholesterol levels, blood pressure, and inflammation may continue to improve (2).

Whether you’re looking to simply pep up your fitness routine, jazz up your diet with mouth-watering low-calorie recipes or want to get your act together and significantly drop that number on your scale – BetterMe app has got you covered! Improve your body and revamp your life with us!

Beyond 3 Months (Long-Term Benefits)

The benefits of intermittent fasting are not limited to the first few months, although relatively little long-term research has been conducted. There is speculation that long-term adherence to this eating pattern can result in further improvements including:

See also
Keto Vs Intermittent Fasting: Is One Better Than The Other?

Reduced risk of chronic disease – with better insulin sensitivity, improved gut health, and lowered inflammation, intermittent fasting may reduce the risk of developing diseases such as diabetes, heart disease, and some cancers (2).

Better weight management – intermittent fasting may help you maintain a healthy weight in the long term by promoting fat loss and preventing weight regain (2).

Improved longevity – as has been suggested by animal studies, calorie restriction through intermittent fasting may increase lifespan and promote healthy aging  (2).

Check out our Intermittent Fasting Guide for more information on getting started with this eating pattern and maximizing its benefits.

Read more: Intermittent Fasting Meals That Will Fit Your 16/8 Schedule

how long does it take for intermittent fasting to work  


  • Can you lose weight in 1 month with 16:8 intermittent fasting?

Yes, it’s possible to lose weight in 1 month with the 16:8 intermittent fasting approach. This method involves fasting for 16 hours each day and eating during an eight-hour window. The weight loss is mainly caused by reduced calorie intake due to the limited eating window. 

However, this is also dependent on what you eat during the eight-hour feeding period. To see optimal results, it’s recommended that you consume a balanced diet that is rich in fruits, vegetables, lean proteins, and whole grains.

  • Is fasting from 7 PM to 11 AM allowed?

Fasting from 7 PM to 11 AM constitutes a 16-hour fasting period and an eight-hour eating window, which makes it a typical 16:8 intermittent fasting schedule. This timeframe is popular as it includes sleep time in the fasting period and allows for lunch and dinner during the eating window, which aligns well with most people’s lifestyles.

  • Is 16:8 intermittent fasting done every day?

The 16:8 intermittent fasting schedule can be done every day, but it’s not a requirement. The flexibility of intermittent fasting is one of its major benefits. Some individuals prefer to fast every day for consistency, whereas others may choose to fast on certain days of the week. It’s important to find a routine that matches your lifestyle and goals.

  • How much weight can I lose with 16:8 intermittent fasting in a week?

Although weight loss results can vary depending on your lifestyle and dietary choices, you can expect to lose approximately 1-2 pounds per week with the 16:8 fasting method or any other method that creates a moderate calorie deficit. This estimate assumes you consume a healthy balanced diet and avoid overeating during your eight-hour eating window and that you also maintain a regular exercise routine.

  • Should I intermittently fast every day?

Intermittent fasting can be effective whether it is done every day or for a few days a week, it’s largely a matter of personal preference. Daily fasting may offer more consistent results and can be easier to maintain as a routine. However, it’s important to listen to your body and adjust your fasting schedule as required.

  • How many times can you eat during 16:8 fasting?

You should eat 2-3 meals during the eight-hour eating window of the 16:8 fasting method. This normally includes lunch and dinner with a light snack in between. You should avoid overeating during your eating window and aim for a balance of proteins, fats, and carbohydrates.

  • How many calories can you eat during 16:8 fasting?

The 16:8 fasting method doesn’t dictate a specific calorie intake. Instead, it restricts the time period during which you can eat. However, if your goal is weight loss, you will need to consume fewer calories than your body burns. On average, women need 1,500 to 2,000 calories per day and men need 2,000 to 2,500, but you can calculate your specific goals based on individual factors.

  • How do I maximize my 16:8 intermittent fasting?

To get the most from your 16:8 intermittent fasting, you need to maintain a nutritious, balanced diet during your eating periods, avoid overeating, and hydrate with Zero Calorie Drinks for Intermittent Fasting during the fasting period. Regular exercise is also beneficial. You should also be consistent because the longer you stick with it, the better your results are likely to be.

  • What are typical 16/8 fasting results after 1 month?

After one month of following the 16:8 fasting schedule, many individuals notice a reduction in body fat, improved energy levels, and better control over cravings. This is largely due to the decrease in daily calorie intake that the restricted eating window promotes. However, these results can vary based on dietary choices during the eating window and individual metabolic rates

  • How much weight loss can be expected from 16:8 fasting after a week?

16:8 fasting weight loss results after one week may vary due to individual factors such as dietary choices and physical activity levels. 

However, a likely outcome is approximately 1-2 pounds per week when a nutritious, balanced diet is maintained during the eating window and regular physical activity is performed. 

Similar to with most other diets or lifestyle changes, intermittent fasting results after one week are dependent on your adherence and other individual factors.

  • What are the expected 16:8 fasting results after 4 weeks?

After four weeks of 16:8 fasting, you may experience noticeable weight loss, improved energy levels, and reduced food cravings. You may also notice improvements in overall health markers such as blood pressure, cholesterol levels, and insulin sensitivity. However, these results can vary based on the quality of your diet during the eating window and your level of physical activity.

  • What are the expected intermittent fasting results after 3 months for women?

After three months of intermittent fasting, women may notice a significant decrease in body fat and weight, improved gut health, and more defined muscle mass. 

Other potential benefits include better insulin sensitivity, more stable energy levels throughout the day, and improvements in overall health markers.

Our Vegan Intermittent Fasting Guide shows how this pattern of eating can be adapted for those who follow a vegan lifestyle.

  • How should I set up my intermittent fasting schedule?

For most people, an eating window from noon to 8 PM works well, as it allows for lunch and dinner, aligns with their social activities, and includes the hours of sleep during the fasting period. However, the schedule can be adjusted according to personal preferences and daily routines.

The Bottom Line

How long it takes to see results from fasting differs. Some results such as increased energy levels and better control over cravings can be experienced after just a few days, while others such as significant weight loss may take several weeks or months. It’s important to find an intermittent fasting schedule that suits your lifestyle and goals and to maintain consistency in order to see optimal results.


This article is intended for general informational purposes only and does not address individual circumstances. It is not a substitute for professional advice or help and should not be relied on to make decisions of any kind. Any action you take upon the information presented in this article is strictly at your own risk and responsibility!


  1. A Scoping Review of the Relationship between Intermittent Fasting and the Human Gut Microbiota: Current Knowledge and Future Directions (2023,
  2. Beneficial effects of intermittent fasting: a narrative review (2023,
  3. Effect of intermittent fasting on circulating inflammatory markers in obesity: A review of human trials (2023,
  4. Intermittent Fasting and Metabolic Health (2022,
  5. Influence of intermittent fasting on autophagy in the liver (2023,nih,gov)
  6. Intermittent fasting positively modulates human gut microbial diversity and ameliorates blood lipid profile (2022,
  7. Intermittent Fasting for Athletes: Can It Improve Performance? (2023,
  8. Improvement in Blood Pressure After Intermittent Fasting in Hipertension: Could Renin-Angiotensin System and Autonomic Nervous System Have a Role? (2023,
  9. Impact of Intermittent Fasting Combined With High-Intensity Interval Training on Body Composition, Metabolic Biomarkers, and Physical Fitness in Women With Obesity (2022,
  10. The Effect of Intermittent Fasting on Appetite: A Systematic Review and Meta-Analysis (2023,
150 million people
have chosen BetterMe

I like very much this application

In one app you have timing for fasting, workouts and calorie counter. Very comfortable to use. And additional service with a meal plan is very useful! I love the recipes it has! They are amazing!...

Fasting program

Gary S.
This fasting program is excellent! Well designed and easy to use. You will get great results.

Such an awesome

Aaron K.
Such an awesome app! been using it for a few months now and I am really happy with the results as the app is incredibly versatile especially if you prefer to work out at home...