If you have an existing health condition or are on medication (e.g., for type 2 diabetes), always consult your healthcare practitioner before attempting prolonged periods of not eating.
Do not restrict eating windows if you are suffering from or recovering from an eating disorder, as this advice may not be suitable for you.
Eat all your meals and snacks within an 8-10 hour window daily to become the ‘master conductor’ of your genetic program, as this influences the timing and expression of over 80% of your genes.
Ensure you have consistent periods of not eating every 24 hours to allow your organs and tissues to repair, reset, and rejuvenate, and to release anti-inflammatory molecules that boost your immune system.
Choose a 10-hour eating window that fits your lifestyle, ensuring your first meal is at least an hour after waking and your last meal is 2-3 hours before bedtime, without necessarily skipping breakfast or dinner.
Establish and adhere to a consistent sleep schedule, aiming for eight hours in bed to get seven hours of sleep, as this consistency optimizes your body’s rhythms and overall well-being.
Ensure your fasting period aligns with your deep sleep, as this is when crucial repair processes for your gut lining and other body tissues occur, free from the burden of digestion.
Avoid eating or consuming tea with milk and sugar for at least one hour after waking, as sleep hormones like melatonin are still high and can inhibit proper insulin release, making your body not ready to digest food perfectly.
Expose yourself to around 1000 lux of light for 30 minutes to an hour in the morning (e.g., by going outside, on a balcony, or opening windows) to synchronize your brain’s circadian clock, reduce sleepiness, and act as a strong antidepressant.
Two to three hours before bedtime, dim all lights at home and use indirect lighting (like table lamps) that doesn’t illuminate your face, to avoid bright light exposure.
Recognize that institutionalized late-night deadlines for homework or work contribute to ‘circadian chaos’ and sleep deprivation; try to complete tasks earlier to protect your sleep.
Consume your first meal of the day (breakfast) at a consistent time daily, as this is the most powerful cue for re-synchronizing all your body’s internal clocks.
For optimal health benefits, aim to finish your dinner by 6 or 7 PM, aligning your eating with your active period and allowing for a longer overnight fast.
Aim to limit your total eating window to no more than 13 hours in a 24-hour cycle to allow for adequate digestion, sleep preparation, and fasting.
Be aware that eating healthy food at the wrong time, especially late at night when your body is not expecting it, can cause your body to react as if it were junk food, leading to negative effects.
If time is limited, prioritize physical activity in the afternoon, as your muscles are more ready, flexibility is better, injury risk is lower, and it’s more effective at reducing blood glucose than morning exercise.
Embrace early afternoon naps, as humans are biologically designed for them, and they can be beneficial for concentration, focus, learning, and creativity.
Do not take naps after 3 PM or 4 PM, as napping too late in the day can interfere with your evening sleep quality.
Enable the ’night shift’ or ’night light’ feature on all your electronic devices to change screen color composition from white to a warmer orange hue, mitigating the impact of blue light on your circadian rhythm and sleep.
Replace regular bulbs in bedside lamps and other evening lighting with low blue light bulbs to create a more relaxing environment and reduce blue light exposure before bed.
Adopting a 10-hour eating window can improve your sleep quality and satisfaction within 2-3 weeks, even if the total hours of sleep don’t significantly increase.
Eating within a 10-hour window can significantly improve gut health and reduce symptoms of acid reflux within 2-4 weeks.
By improving sleep and gut health through time-restricted eating, you will experience an enhanced sense of energy throughout the day.
Individuals with pre-diabetes or type 2 diabetes (on minimal medication) may experience improved blood sugar control, especially during fasting periods, by adhering to a 10-hour eating window.
Time-restricted eating can lead to improvements in both systolic and diastolic blood pressure within 6-8 weeks for individuals with hypertension.
Time-restricted eating can improve kidney function, muscle repair, and aid in recovery from injuries by supporting the circadian clock’s role in repairing tendons and ligaments.
Time-restricted eating can enhance athletic performance, including strength and endurance, potentially leading to significant improvements in competitive activities.
Eating within an 8-10 hour window can inadvertently lead to a modest reduction in calorie intake (5-20%) and an improvement in nutrition choices, such as reduced alcohol and processed food consumption.
If you are on hypertensive drugs or have pre-diabetes/type 2 diabetes, monitor your blood pressure (after 4-6 weeks) and blood sugar (after 10-12 weeks) when adopting a 10-hour eating window, as medication adjustments may be necessary.
If you desire a hot drink within the first hour of waking, choose black coffee, black tea, or herbal tea to avoid interfering with insulin release and blood sugar processing.
If you consistently need coffee or tea to combat morning sleepiness, it’s a warning sign of insufficient sleep, suggesting you should consider going to bed earlier.
If you experience morning acid reflux from strong coffee, consider having a little food with it, as historically, this practice led to the development of breakfast to reduce such effects.
If indoors, sit by a window to get 800-1000 lux of light, or if in the bathroom, crank up dimmable lights or use integrated mirror lights to full strength to get adequate morning light exposure.
Integrate exercise with morning light exposure by taking a walk or run outdoors, or choosing a gym with ample natural light, to leverage the reciprocal benefits of both on your circadian clock.
Understand that it generally takes one day to reset your sleep-wake cycle for every hour of time zone change, so plan accordingly for recovery after travel or social jet lag.
Aim to maintain a 10-hour eating window for 5-6 days a week, allowing for one ‘cheat day’ where you can slightly extend your eating window, and still experience significant health benefits.
Consume your sweet treats or complex carbohydrates earlier in the day when your body’s blood sugar control is more efficient, as glucose regulation is less effective in the evening.
Plan your dinner to include more protein and fat, as these macronutrients can help sustain you through the nightly fast and align better with your body’s evening physiology.
Bodybuilders who switch from frequent eating to time-restricted eating often report reduced acid reflux and increased energy levels throughout the day.
Consider delaying your breakfast to align with your body’s natural hunger cues, which often peak in the evening, and to accommodate social and cultural aspects of dinner.
While striving for optimal health, remember to balance the pursuit of perfection with practical considerations and choose an eating pattern that sustainably suits your lifestyle.
If you choose a very compressed eating window (e.g., one meal a day), ensure that meal is nutritionally balanced with the right proportion of macronutrients and micronutrients to avoid deficiencies.
Objectively monitor your current eating window to understand your habits, as many adults unknowingly eat for 15 hours or longer, which can be a starting point for making beneficial changes.
When adopting new eating patterns, especially if you have existing health conditions, seek support and education to help you adapt and sustain the changes.
Adjust the default brightness setting on all your electronic devices to the minimum, so they automatically revert to a low brightness at night, reducing disruptive light exposure.
When flying eastbound (e.g., US to Europe), fast during the flight, finish your last meal before boarding, and minimize light exposure (using an eye mask) to help reset your body clock to the new time zone upon arrival.
After an eastbound flight, have a substantial breakfast around 10 AM (after a long fast) to help reset your body clock to the new time zone.
When flying westbound (e.g., UK to US), eat your meal on the plane, but upon landing in the evening, skip dinner and fast until breakfast the next morning to aid in time zone adjustment.
Even on 24-hour shifts, shift workers can adopt a 10-hour eating window, often choosing a daytime window ending between 7-9 PM, which can lead to more energy and better sleep on off-days.
For shift workers with frequently changing schedules, try to maintain a consistent eating window (e.g., noon to 10 PM) across both work and off days to minimize circadian disruption.
If driving home after a night shift, prioritize safety by consuming black coffee or tea if needed, but consider decaffeinated options or public transport to avoid caffeine’s interference with restorative sleep.
Consider exceptions for morning coffee if your job requires high alertness (e.g., physician), for public safety while driving, or if it’s a deeply cherished personal habit.