Can You Do a 16:8 Fast Every Day?

Yes, you can! Daily 16:8 time-restricted feeding (TRF) is safe to practice as long as you are acquiring the energy and nutrition that you need within your eating window; 8-hours is typically more than enough time to consume your daily energy/nutrition requirements. Exceptions apply to those who require longer eating windows in order to comfortably consume their daily requirements (e.g., athletes). 

Our bodies function optimally with this rhythmic alternation of fasting and feeding. Circadian biologists believe that sustained daily rhythms of periodic fasting are beneficial for maintaining robust circadian rhythms which are increasingly being linked in the research to overall healthspan and lifespan.

Circadian rhythms are roughly 24-hour cycles in human metabolism, physiology, and behavior. The concept of TRF is to time eating and fasting appropriately within these cycles on a daily basis so that the environmental cues that control these rhythms are all in sync. Certain processes take place in the fed state that don’t take place in the fasted state, and vice versa. But both are required for optimal health, and they can’t all be turned on at the same time. Without a regular daily fasting window, we can disturb the essential processes within the fasted state (e.g., cellular repair).

Ultimately, a regular daily fasting/feeding routine strengthens our circadian clocks and supports the processes that differentially take place in the Fasting and Eating Windows. That said, don’t feel like you can’t veer away from your daily fasts every once in a while. Our biology tends to respond to chronic signals (what you do most of the time), not the “one-off” late-night eating with friends, so don’t beat yourself up for letting loose every now and again. Giving yourself permission to take it easy is important too.


Longo VD, Panda S. Fasting, Circadian Rhythms, and Time-Restricted Feeding in Healthy Lifespan. Cell Metab. 2016;23(6):1048-1059.

About the Author: Kristi Storoschuk

Kristi Storoschuk is a science communicator who focuses her research on ketogenic diets, metabolic therapies, and fasting for health optimization. She currently works alongside the world’s leading ketogenic researchers providing scientific education for the mainstream audience. She completed her Bachelor of Science (Honours) at the University of Guelph in Ontario, Canada. Outside of her research, she spends her time doing CrossFit and optimizing her health with an ancestral approach.

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Kristi Storoschuk
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