16:8 Intermittent Fasting: Complete Beginner’s Guide for 2026
What 16:8 Means
16:8 means 16 hours of fasting followed by an 8-hour eating window. Most common schedule: skip breakfast, eat from 12 PM to 8 PM (or 1 PM to 9 PM), then fast until noon the next day. You’re actually fasting for the sleep hours too — the fast is only 7–8 hours of actual waking fasting.
What Breaks a Fast
Breaks the fast (raises insulin): food of any kind, sweetened beverages, milk or cream in coffee, fruit juice. Does not break a fast (doesn’t significantly raise insulin): plain water, plain black coffee, plain tea, sparkling water without sweeteners. The standard working definition for 16:8 is no caloric intake during the fasting window.
What to Eat in the Eating Window
16:8 does not dictate what to eat — only when. However, the protocol works best with: adequate protein (1.6–2g/kg), whole foods, sufficient vegetables and fiber, and not using the eating window to overeat. Without calorie awareness, some people compensate for the missed breakfast with larger meals and see minimal results.
First 4 Weeks: What to Expect
Week 1: hunger in the morning, some irritability, possible headaches (especially without caffeine). These reduce significantly by week 2. Week 2: hunger patterns shift — most people report morning hunger diminishing. Week 3: energy more stable through fasting window. Week 4: the new pattern feels natural. Use Intermittent Fasting to track your eating and fasting windows.
Frequently Asked Questions
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