How Long Does it Take for 16/8 Intermittent Fasting to Work?

Results may vary from person to person, but most people will see changes after practicing consistently for a few weeks to a few months.

If you’re thinking about trying 16/8 intermittent fasting you should know what to expect. Within the first week or two you may experience changes in your energy levels, hunger cues and digestion.1  The effects of fasting can vary from person to person.

How quickly I will lose weight?

When it comes to weigh loss, it is true that intermittent fasting can help you lose weight. Still, it’s important to be patient and remember that you won’t get results overnight. The amount of weight you lose and how quickly you will lose it depends on your starting weight, body composition and how well you stick to your fasting schedule. You may notice changes in your body weight and composition within a few weeks to a few months of consistent intermittent fasting practice.2

What about my belly fat?

To reduce your belly fat, you should not only commit to a 16/8 intermittent fasting schedule, but ensure that you eat a balanced diet and exercise regularly in order to reduce belly fat over time.3

Some people may experience significant changes relatively quickly, while others may require more time to see noticeable results.


  1. Wang, Y., & Wu, R. (2022). The Effect of Fasting on Human Metabolism and Psychological Health. Disease Markers, 2022, 5653739.
  2. Diet Review: Intermittent Fasting for Weight Loss | The Nutrition Source | Harvard T.H. Chan School of Public Health. (n.d.). Retrieved 22 April 2024, from
  3. Taking Aim at Belly Fat—Harvard Health Publications—Harvard Health. (n.d.). Retrieved 22 April 2024, from

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