How to break a fast — your plan

You fasted: 72 hours to 5 days · Three to five days.

Take a full day to come back, not a meal. Read the risk criteria before you start, not after.

How well this is known: The stepwise shape is drawn from a published clinic protocol followed by 1,422 people. That is real evidence for how it is done and not evidence that it works, because the study measured everybody at the end of the fast and nobody during the four days of eating that followed.

Day 1, minute 0

A piece of fruit, eaten slowly

The fasting clinic whose protocol this shape comes from breaks its fasts with an apple at lunch, and calls that a tradition rather than a finding — it appears on the clinic's own pages and nowhere in the paper. Small, watery, and something that takes ten minutes to chew.
- Bone broth one mug, sipped over 20 minutes
- Vegetable broth one mug, sipped over 20 minutes
- Miso soup one small bowl
Day 1, a few hours in

A light soup, and nothing else

The whole of day one is a few hundred calories of soft, low-fat, mostly plant food, split into small servings. It is a day, not a course.
- Soft-scrambled or boiled eggs one or two
- Plain yoghurt or kefir a small pot
- Avocado half
- Steamed or cooked vegetables a small bowl
Day 2

Small meals, still light

Roughly half of what you normally eat, in three or four small meals, still soft and still low in fat. The published protocol ramps from about 800 to about 1,600 kcal a day across four days.
- Chicken or turkey with cooked vegetables a normal plate
- Oily fish with vegetables a normal plate
- Eggs with vegetables and toast a normal plate
- Lentil or bean stew a normal bowl
Day 3 onwards

Back to normal food

Normal meals at normal sizes, from the list above or from your own kitchen. Keep the salt going for another day or two.

Avoid at first

A sugary drink or dessert as the first thingThe one avoid line that applies at every band, and not for the reason usually given: the longer the fast, the BIGGER the glucose rise from the same carbohydrate, because a fast lowers insulin sensitivity rather than raising it. It is a spike, not a crash. Nothing about it is dangerous in a healthy person; it is simply the most pointless way to spend the first thing you eat.
Eating until you are full because you earned itThe hunger after a long fast overshoots what you need, and it does not stop being hunger when you have had enough. Stop while you could still eat more.
AlcoholOn an empty stomach after a long fast it arrives faster and hits harder, and it is a poor first thing to ask a quiet gut to process.
A large raw salad, or raw cruciferous vegetablesRaw fibre is the hardest thing there is for a gut that has spent a day doing nothing. Bloating and cramps, reliably. Cook them and they are fine.
Deep-fried or heavily processed foodHard work to digest at the best of times, and this is not the best of times.
A large portion of nuts or seedsDense, fatty and full of fibre. A handful in a meal is fine; a bowl of them as the first food is not.
A big glass of milk or a large serving of unfermented dairyLactose tolerance is a spectrum, and a large dose of it as the first food after a day is how people who did not know they were at the sensitive end find out.
A large, fatty mealFat slows the stomach down. That is useful when you are eating normally and unhelpful when the stomach is already slow.
Making up the missed calories in one sittingThe day is the unit past 36 hours, not the meal. Spreading the food out is the single most useful thing on this list.
Going straight back to your normal trainingGive it a day. Hard training on the first day back stacks a second demand on top of the one your body is already dealing with.
Caffeine on top of the first mealCoffee lifts colon motor activity within minutes, which is not what a gut coming back from three days needs on top of food.

Refeeding risk — the criteria clinicians work from

This checklist is about the state you were already in, not about the length of one fast. Read it before you fast rather than before you eat again. Any one of the first list, or any two of the second, and this belongs with a clinician rather than a web page.

Any ONE of these

BMI less than 16 kg/m²
Unintentional weight loss greater than 15% within the last 3 to 6 months
Little or no nutritional intake for more than 10 days
Low levels of potassium, phosphate or magnesium before feeding

Or any TWO of these

BMI less than 18.5 kg/m²
Unintentional weight loss greater than 10% within the last 3 to 6 months
Little or no nutritional intake for more than 5 days
A history of alcohol abuse, or drugs including insulin, chemotherapy, antacids or diuretics

Stop and get medical help if, after you start eating again, you become confusion, or difficulty thinking clearly; breathlessness; a racing or irregular heartbeat; fainting, or feeling close to it; swelling in the legs or ankles after you start eating again. None of those is a symptom to push through.

Portions are rules of thumb, not measurements. No study has established the right first-meal size after any length of fast, and this sheet says so rather than printing a figure it cannot defend. What is reliable is the direction of the error: people overshoot. Stop while you could still eat more.

Never skip, delay or adjust medication to protect a fast. If a medicine needs food, the food wins. Nothing on this sheet is medically reviewed; every guideline figure on it names the guideline it came from.

getfasted.app/tools/how-to-break-a-fast — every length, with the reason behind each step. Not medical advice.