How many calories to eat during intermittent fasting 16/8

Thinking about trying the 16/8 diet? Read this article to learn how many calories you should be eating.
Icon check
Include trusted sources

Curious to know how many calories you should be eating while on the 16/8 diet? Read this article to get some answers!

Written by
Christine Richardson, PhD
Clinical Project Manager at Becton Dickinson

The 16/8 intermittent fasting diet is probably the most popular form of fasting. This is because it’s one of the easiest to make a habit since it is practiced daily and because it has one of the largest eating windows. 

But the question many people have is how many calories to eat during intermittent fasting 16/8? 

This is a good question and we’ll do our best to explain how many calories to eat in order to achieve your health and weight loss goals. 

The 16/8 Diet

Golden clock on a black background.

First, let’s briefly describe what the 16/8 intermittent fasting diet is. 

This diet means that individuals will eat for 8 hours of the day and fast for the remaining 16 hours. For most people, this means that they will simply skip breakfast or eat a later breakfast with their eating timeframe being around 12pm-8pm. 

What’s important to know about this routine is that you need to be consistent with your eating window in order for it to work. This means that you shouldn’t eat from 12pm-8pm one day and then 7am-3pm the next.


It seems like many people these days are afraid of calories, so let us make one thing clear – your body NEEDS calories. Calories serve to give our body energy to function.

We should practice being mindful of the number of calories we eat but we also should not fear them and recognize that our bodies do need them.

Join 100s of women getting in
better shape with intermittent fasting
The confidence boost you need to get results.
Woman laughingWoman laughingWoman smilingWoman with glasses laughing
Already +55 000 subscribers on board 🙌
Share your email, and you will get access to our private community

of women achieving results with intermittent fasting

How many calories to eat during 16/8

Now, knowing how many calories to eat during intermittent fasting 16/8 can be a little tricky because it is going to depend on your sex, age, height, weight, and activity level. 

If you need help calculating this, there are many websites available that can help you like this one here. If you have additional questions, you may want to consult your primary care physician or a registered dietitian (RD). 

Regardless of you trying the 16/8 for weight loss or to improve your overall health, we recommend you don’t decrease your caloric intake to an amount below what your body needs. The reason for this is that you can still lose weight through intermittent fasting and because entering into a calorie deficit for too long can have some negative health consequences. 

To elaborate, restricting calories can cause you to lose muscle mass. This will reflect a lower number when you step on the scale, but this isn’t good news. Losing muscle mass can hurt your weight loss goals long-term because muscles burn a lot of calories. This means that the less muscle mass you have, the fewer calories you are going to burn each day…this also means you will need to eat less calories each day, which becomes difficult to sustain long-term.

Another reason to not decrease your caloric intake is because when you do this for a long time, your body learns to adapt. This means that your body will actually conserve energy and burn less calories each day. This is why people often plateau when they cut calories (1).

Fasting Burns Fat

Blue, empty plate with the words Burn fat

Despite you not decreasing your calories, you can still expect to lose some unwanted body fat while keeping your muscle mass with the 16/8 diet.

Fasting actually “trains” your body to use more of its stored fat for energy as opposed to our stored sugar (glucose), so decreasing your calories isn’t necessary (2).

Studies also show that if you maintain your calories, you can still obtain all of the numerous health benefits associated with fasting like lowering entering a state of autophagy, decreasing blood glucose levels, and more (3,4,5). 


If you’re going to start the 16/8 intermittent fasting diet, try not to decrease your caloric intake. By maintaining your calories, you can still lose body fat and reap the benefits associated with intermittent fasting.

To see some success stories with intermittent fasting and to get answers to any of your questions, join our community for women only! 


1. Dulloo AG, Jacquet J, Montani JP. How dieting makes some fatter: From a perspective of human body composition autoregulation. Proceedings of the Nutrition Society. 2012. p. 379–89. 

2. Anton SD, Moehl K, Donahoo WT, Marosi K, Lee SA, Mainous AG, Leeuwenburgh C, Mattson MP. Flipping the Metabolic Switch: Understanding and Applying the Health Benefits of Fasting. Obesity. Blackwell Publishing Inc.; 2018. p. 254–68. 

3. Stockman MC, Thomas D, Burke J, Apovian CM. Intermittent Fasting: Is the Wait Worth the Weight? Current obesity reports. NIH Public Access; 2018. p. 172–85. 

4. Moro T, Tinsley G, Bianco A, Marcolin G, Pacelli QF, Battaglia G, Palma A, Gentil P, Neri M, Paoli A. Effects of eight weeks of time-restricted feeding (16/8) on basal metabolism, maximal strength, body composition, inflammation, and cardiovascular risk factors in resistance-trained males. J Transl Med. BioMed Central Ltd.; 2016;14. 

5. Mattson MP, Longo VD, Harvie M. Impact of intermittent fasting on health and disease processes. Ageing Research Reviews. Elsevier Ireland Ltd; 2017. p. 46–58. 

Signup for our Newsletter

Value bombs, straight to your inbox.
You may also be interested in...