You'll sleep through 8 of the 16 fasting hours — only 8 waking hours take any attention at all.
This is one part of the system. The book connects the rest · from £1.77 (UK price) →
A planning tool, not medical advice. If you're pregnant, diabetic, on medication, or managing a health condition, talk to your clinician before changing how you eat.
Your window ends before your evening does. The planner closes the eating window three to four hours before bed — the book’s evening guideline — with Earlier giving the full four. Finishing food well before sleep tends to mean better sleep, and better sleep makes the next morning's fast almost effortless.
Most of the fast happens while you're asleep. That's the quiet trick of 16:8 — arrange the window well and half the fasting hours cost you nothing. The dial shows the split: the pale arc is sleep, and only the unmarked waking stretch asks anything of you.
Two meals, not grazing. The first meal breaks the fast; the second closes the window. The space between them is part of the design — steady energy without the constant negotiation of snacks. The full reasoning is in the two-meal-a-day guide, and the system it belongs to is the book.
Salt is not optional. On low carb your kidneys shed sodium faster, and the classic mid-morning fasting headache is usually that, not hunger. Hence the electrolyte moment on the dial — the details are in the electrolytes guide. And once the times are set, the macro calculator fills in what each meal should carry.
Finishing your final meal three to four hours before sleep — the book's evening guideline — gives digestion time to settle, which most people find improves sleep quality, and better sleep makes the next day's fast easier. It also means more of your fast happens overnight, where it takes no willpower at all.
Yes — and if fasting is new to you, you probably should. 14:10 is a gentler rhythm that lets your body adapt before you narrow the window. Switch the planner to 14:10, run it for a couple of weeks, then move to 16:8 when the morning stretch feels easy.
No. The times are anchors, not rules. Within half an hour either side is fine. What matters is that the rhythm repeats — the same shape to every day. Consistency is the mechanism; precision is optional.
Water, black coffee, and plain tea — nothing with calories. A glass of water with a pinch of salt during the morning stretch covers the sodium your body sheds on low carb and heads off most fasting headaches.
Five phases from reset to lasting rhythm — the two-meal pattern, the electrolyte work, and what to do when life gets in the way.
Limited-time launch pricing · Kindle £1.77 · Paperback £5.64 · Hardback £10.48UK store shown · other Amazon stores list local equivalents