Intermittent Fasting Window & Eating Schedule Calculator

Intermittent Fasting Guide

Intermittent Fasting Protocols

16:8: most researched and popular protocol. Fast 16 hours (including sleep), eat within an 8-hour window. A typical schedule: last meal 8pm, first meal 12pm. 18:6: more restrictive eating window. Often used when 16:8 results plateau. 20:4: significantly restricts eating opportunities — requires meal planning. OMAD: one meal per day. Very restrictive, difficult to meet nutritional needs. 5:2: eat normally 5 days per week. On 2 non-consecutive days, eat only 500-600 kcal. Each protocol can achieve

What Breaks a Fast?

Breaks a fast: any caloric food or drink. Milk or cream in coffee. Fruit juice. Alcohol. Energy drinks with calories. Does NOT break a fast: water. Plain black coffee or tea (no milk, no sugar). Sparkling water. Electrolyte drinks with zero calories. Plain herbal tea. Black coffee in particular does not break a fast and may support fasting by reducing hunger. Chewing gum: technically zero calories but insulin response may be triggered in some people. Medications: most medications are fine to tak

Evidence for Intermittent Fasting

Weight loss: IF produces similar weight loss to continuous calorie restriction when total calories are matched — the advantage is that some people find it easier to restrict calories within a compressed window. Metabolic benefits: some evidence for improved insulin sensitivity, reduced fasting insulin, and autophagy (cellular repair) during extended fasting. Conflicting evidence: some studies show muscle loss risk with extended fasting without adequate protein. Recent research suggests that the

Practical Fasting Tips

Starting out: begin with a 12-hour fast (e.g. 8pm to 8am) — this is the baseline most people already achieve naturally. Gradually extend to 14 hours, then 16. Breaking the fast: break with a protein-rich meal to maximise satiety through the eating window. Coffee or tea (black) in the morning significantly reduces hunger and supports extending the fast comfortably. Electrolytes: extended fasts can deplete sodium and potassium. A pinch of salt in water or a zero-calorie electrolyte supplement supp