TempoLife › Features › Free email courses › fasting-7-day

Seven days to an eating window

One short lesson a day for a week, building from "what does fasting actually mean" to an eating window you can keep without thinking about it.

What you will do

By the end of the week you will know your current eating window to the nearest half hour, you will have chosen a target window that fits your life rather than someone else's, and you will have run it for at least three days.

Who it is for. People who eat reasonably well but at scattered times, who have heard of 16:8 and want to know whether it is worth doing, and who would rather change when they eat than count everything they eat.

This course is not for you if you are pregnant or breastfeeding, under 18, underweight, have a current or past eating disorder, or take medication where meal timing matters — insulin and sulfonylureas above all. Skipping meals is not a small change when you take glucose-lowering medication. Talk to your own clinician first, and if they say no, that answer beats anything in this course.

The full curriculum

All 7 lessons, in order. This is the complete course — reading it here needs no sign-up and no email address.

Day 1: What fasting is, and what it is not

The plain definition, what the popular claims actually rest on, and why "eating window" is a more useful phrase than "fasting".

Time-restricted eating means confining the day's food to a set number of hours and drinking only water, black coffee or plain tea outside them. That is the whole idea. 16:8 means a sixteen-hour gap and an eight-hour window; 14:10 and 12:12 mean what they look like. Nothing is being detoxed, nothing is being reset, and no organ is being cleaned.

The honest summary of the evidence is smaller than the headlines: most trials find that people eating in a shorter window tend to eat somewhat less over the day, and that most of the weight change follows from that rather than from the timing itself. Some studies find small additional effects on blood sugar and blood pressure; others do not. It is a scheduling tool that helps a lot of people eat less without counting, and that is a genuinely useful thing to be.

That framing matters for this week. If you approach it as a metabolic switch you have to flip perfectly, one late dinner feels like failure. If you approach it as "I stop eating after eight and I am fine with that", it survives a birthday.

Today: Write down, in one sentence, why you want to try this. Keep it — you will read it again on day seven.

Day 2: Find the window you already have

Measuring your current first and last bite for a single ordinary day, and why the number is almost always bigger than people guess.

Before changing anything, measure. Today, note the clock time of your first bite of anything with calories in it and the time of your last. Not the meals — the bites. The coffee with milk at 07:10 counts. The three crisps at 22:40 while cooking tomorrow's lunch counts.

Most people who have never measured this find a window between thirteen and sixteen hours, and are surprised by it, because they think of themselves as eating three meals. The gap between the remembered day and the recorded day is the single most useful thing this course produces, and it takes no effort to find.

Do it for a normal day, not a good one. A day where you deliberately behave produces a number you cannot act on.

Today: Record your first bite and last bite today. Two times, written down. That is all.

Day 3: Choose a window you can actually keep

Working backwards from your fixed points, the case for starting at 12:12, and why the popular 16:8 is the wrong first target for most people.

Take yesterday's number and shorten it by one to two hours, not by five. If your window was fifteen hours, aim for thirteen. If it was thirteen, aim for twelve. The target is a window you will still be running in three weeks, and the strongest predictor of that is how little you had to change.

Work backwards from the fixed points in your life rather than from a number on the internet. If your family eats at 19:30, your window closes at 20:30 and there is nothing to discuss. If you train at 06:30 and need to eat afterwards, your window opens at 08:00. Two fixed points usually determine the whole thing.

One rule of thumb worth following: it is far easier to move the end of the window earlier than to move the start later. Late-evening eating is mostly habit and boredom; morning eating is often genuine hunger. Cut the evening first.

Today: Write your target window as two clock times, for example 09:00 to 20:00. Put it somewhere you will see it tonight.

Day 4: The first difficult evening

What evening hunger is actually made of, the three-question test, and what to do instead of eating.

Tonight, or a night this week, you will want something after the window closes. It helps to know what you are dealing with. Hunger that arrives on a schedule, at the time you usually eat, and passes in twenty minutes whether or not you feed it, is a habit signal. Hunger that builds steadily, does not go away, and comes with a genuinely empty stomach is not. The first is worth sitting through; the second is worth eating for.

The three-question test: would I eat an apple right now? Did I eat enough protein today? Am I bored, tired or annoyed? A no to the first usually means it is not hunger. A no to the second means the fix belongs in tomorrow's lunch, not tonight. A yes to the third means the food would have worked, briefly, and then not.

Have a replacement ready rather than relying on willpower. Sparkling water, a large mug of herbal tea, cleaning the kitchen, going to bed twenty minutes earlier. The point is to occupy the twenty minutes, because that is usually the whole duration of the problem.

Today: Decide now what your after-window drink is, and put it somewhere visible.

Day 5: What goes in the window

Why a short window makes protein and fibre matter more, and the one meal most people should change.

A shorter window means fewer eating occasions, which means each one has to do more work. The two things that make a meal hold are protein and fibre: they are the components most consistently associated with feeling full, and they are the two most people are short of when they eat in a hurry.

A practical target that needs no counting: something with real protein at every meal inside the window — eggs, fish, meat, dairy, pulses, tofu — and something with a skin, a stalk or a shell at every meal too. If you can name the protein and name the vegetable, the meal is fine.

The meal to change first is almost always the first one, because a first meal of bread and jam at 11:00 sets up a hungry afternoon and a difficult evening. Swap it for something with protein in it and the evening problem you had on day four often shrinks on its own.

Today: Plan tomorrow's first meal in the window so it has an obvious protein in it.

Day 6: Coffee, drinks, and what breaks a window

The practical rule for drinks, what the arguments about "breaking a fast" are really about, and the alcohol problem.

The practical rule: water, black coffee and plain tea outside the window; anything with calories inside it. That is not a physiological law, it is a rule that is simple enough to follow. The internet arguments about whether ten calories of milk "breaks a fast" matter for laboratory measures and not for what you are doing this week.

A splash of milk in a morning coffee will not undo anything. A latte is a small meal and belongs in the window. If you are unsure, ask whether it would appear in a food diary; if the answer is yes, it goes inside.

Alcohol is the awkward one, and worth being blunt about. It carries roughly seven kilocalories per gram, it lowers the resistance that keeps the window shut, and it degrades sleep in a way you will feel the next day. It belongs inside the window if it belongs anywhere, and a drinking evening is one of the two or three reliable ways this whole plan comes apart.

Today: Look at what you drink between the window closing and bed. Change one of them.

Day 7: Making it the default — and when to stop

Turning a week into a habit, what to measure from here, and the honest list of reasons to abandon it.

A week is enough to know whether a window fits your life; it is not enough to know what it does to your body. If you want to keep going, change nothing for another three weeks and then look at three things: your weight trend, how you feel in the late afternoon, and whether the window is something you now do or something you still fight.

Read the sentence you wrote on day one. If the reason still holds and the window has stopped being work, you are finished — this is now just how you eat, and there is nothing further to do.

And the honest other half. Stop if you are thinking about food more than you were before you started; if the window has turned into a rule you feel guilty about breaking; if you are bingeing when it opens; if you are sleeping worse; or if you feel light-headed, cold or exhausted. Time-restricted eating is one tool among many and it suits some people and not others. Abandoning it is a legitimate outcome of this week, not a failure of it.

And the standing caution, one last time: if you are pregnant or breastfeeding, under 18, underweight, have a history of disordered eating, or take medication where meal timing matters, this is a conversation with your clinician rather than a course.

Today: Decide, in writing: keep it, adjust it, or stop. All three are real answers.

Get it as a daily email

Sign-ups are recorded but the automated sender is not live yet, so no email will arrive until it is switched on. This is a double opt-in: the first thing sent, once live, is a confirmation you must click.

By signing up you agree only to receive this one course. You can unsubscribe from any lesson, and your address is used for nothing else. See the privacy notice.

Frequently asked questions

Source: TempoLife editorial policy · checked 2026-09-02

Other courses

All courses · Quizzes