What doesn't break a fast

Water, black coffee, plain tea and salt are your friends.

Key points

• Anything with essentially no calories keeps you fasted: water, sparkling water, black coffee, plain tea, salt and most electrolyte powders without sugar.
• Caffeine modestly reduces appetite and increases fat oxidation. Two to three cups spread through the day is fine for most people.
• Milk, cream, sugar, honey, juice and bone broth do contain calories. A splash of milk won't ruin everything, but it's not a “clean” fast.
• Zero-calorie sweeteners don't raise insulin meaningfully, but for some people they trigger cravings. Try a week without and see.
• Avoid caffeine after early afternoon — poor sleep is one of the biggest drivers of next-day cravings.

Hunger Wave provides general educational information based on published research. It is not medical advice and does not replace a consultation with a healthcare professional. Stop fasting and seek help if you feel unwell.