If you skip breakfast for a 16:8 window, or just eat later than usual, your first meal is the one that decides how the rest of the day feels. Many beginners worry that they must "ease back in" with something special. For an ordinary overnight or 16-hour fast, you don't: there is no special refeeding routine. What matters is the same thing that matters at any meal, what is actually on the plate.
The main reason to care is hunger. After a long gap it is easy to grab whatever is fastest, such as a pastry, juice or sweet cereal, and be hungry again an hour later. A classic study that fed 38 foods to volunteers and tracked fullness over two hours (Holt and colleagues, 1995) found that fullness rose with a food's weight, protein, fibre and water content, and fell with fat and how tasty people rated it. A croissant scored lowest, boiled potatoes highest. It was a small, short study, so treat it as a hint, not a rule.
Build your first meal. Tap foods to add them (tap again to remove). Amounts are rough, typical portions.
After a normal fast, your first meal doesn't need to be special. Make it a proper one: protein, fibre, and a carb you enjoy.
Think of three parts. Something with protein (eggs, yoghurt, fish, tofu, beans or lentils). Something with fibre (vegetables, fruit, beans, wholegrains). And a carbohydrate you enjoy, ideally a wholegrain one. UK government advice is 30 g of fibre a day for adults, and WHO says at least 25 g, yet many people average around 20 g, so a fibre-rich first meal is a handy head start.
Drinks count too. WHO advises keeping free sugars below 10% of daily energy (about 50 g on a 2,000 kcal day), with 5% or less possibly offering extra benefits. One glass of juice or one sweet pastry can use up a good part of that in a few minutes.
If you are very hungry, start with a glass of water and sit down to eat rather than eating on the move. There is no strong research showing that one particular first food is magic, and results on meal timing are mixed, so pick what suits your day and your tastes. If a fast leaves you dizzy, shaky or unwell, that is a sign to eat and to rethink the fast, not to push on.
This guide is about ordinary short fasts by healthy adults. Refeeding problems happen after little or no food for many days, in people who are underweight or have lost weight unintentionally. NICE lists little or no intake for more than 5 days (alongside other risks) as a warning sign, and that needs medical supervision, not a guide.
This is general information, not medical advice. If you have a condition, are pregnant or breastfeeding, have or have had an eating disorder, or take medication (especially for diabetes or blood pressure), talk to a doctor or dietitian before fasting or changing how you eat.