How this calculation works
The Intermittent Fasting Schedule Planner calculates your exact daily fasting window, eating window, metabolic fat-burning phases, and ketosis/autophagy timeline milestones.
Mathematical formula and logic
Eating Window Hours = 24 - Fasting Protocol Hours. Last Meal Cutoff = (First Meal Hour + Eating Window Hours) mod 24.
Worked example
On a 16:8 protocol starting your first meal at 12:00 PM: Your 8-hour eating window runs from 12:00 PM to 8:00 PM. Your 16-hour fast runs from 8:00 PM until 12:00 PM the following day, achieving peak fat oxidation between hours 12 and 16.
Calculation assumptions
- Zero-calorie beverages (water, black coffee, unsweetened green tea) do not break the fast.
- Eating window provides complete balanced macronutrient and micronutrient intake.
Frequently asked questions
What can I drink during the fasting window?
Water, sparkling water, black coffee, and plain unsweetened herbal or green tea contain virtually zero calories and will not break your fast or spike insulin.
What is the 16:8 intermittent fasting schedule?
The 16:8 method involves fasting for 16 consecutive hours each day and consuming all daily calories within an 8-hour window (e.g. 12:00 PM to 8:00 PM).
When does autophagy begin during fasting?
Cellular autophagy (recycling of damaged cellular components) typically begins around 16 to 18 hours of continuous fasting and peaks between 24 and 48 hours.
Does intermittent fasting cause muscle loss?
No, as long as you consume adequate daily protein (1.6-2.2 g/kg) and engage in regular resistance strength training, intermittent fasting preserves lean muscle while targeting body fat.
Who should avoid intermittent fasting?
Pregnant or breastfeeding women, individuals with a history of eating disorders, and those with Type 1 diabetes should avoid fasting protocols without physician supervision.
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