Food & fasting

Sixteen-hour daily fast with an eight-hour eating window. Tracked by window adherence rather than food content.

Eighteen-hour fast with a six-hour eating window. A tighter variant of 16:8.

A full calendar day with no food, logged as one entry per day rather than a start and end time.

Normal eating five days a week with two non-consecutive restricted days of roughly 500–600 kcal.

Alternating fast days and normal eating days.

A daily calorie or protein target, tracked by adherence rather than by the food itself.

Carbohydrate intake varied across the week, commonly aligned to training days.

Animal foods only, with carbohydrate intake close to zero. Fibre and micronutrient coverage are the open questions.

A fast beyond 24 hours. Electrolytes and refeeding become the practical concerns as duration grows.

Very low carbohydrate intake, typically under 50 g daily, to sustain nutritional ketosis.

Reduced carbohydrate intake without necessarily reaching ketosis, commonly 50–130 g daily.

Pattern emphasising olive oil, fish, vegetables, legumes and whole grains. Among the best-evidenced dietary patterns.

A single daily eating occasion, effectively a 23:1 window. Hitting protein and micronutrient targets in one sitting is the practical difficulty.

Excludes grains, legumes, dairy and refined foods. Carbohydrate intake is unrestricted from whole-food sources.

Excludes all animal products. B12 supplementation is required; iron, zinc, omega-3 and iodine warrant attention.

Excludes meat and fish while retaining dairy and eggs.