You can weigh food cooked or raw — what matters is that the weight and the database entry use the same basis. Cooking changes how much water a food holds, so it changes the grams without changing the calories, and every entry in a food database is written for one state or the other. Weigh raw and log against a raw entry, or weigh cooked and log against a cooked entry, and the number is right either way. Cross them and the error can be a quarter of a meal in one direction or a multiple of it in the other. This is a method page; the worked figures are illustrations marked "suppose", not measurements of any particular food.
Why the numbers differ
Calories live in the protein, fat and carbohydrate of a food. Water carries none. Cooking moves water in or out:
| Food type | What cooking does | Calories | Grams | Calories per gram |
|---|---|---|---|---|
| Meat, fish, poultry | Loses water (and sometimes fat) in the pan | About the same | Fall | Rise |
| Rice, pasta, oats, dried beans | Absorb cooking water | The same | Rise, often several-fold | Fall sharply |
| Vegetables | Lose water when roasted, gain some when boiled | About the same | Vary either way | Vary |
| Eggs, most dairy | Little change | The same | About the same | About the same |
The per-gram column is the one that logs are built on. A database entry says "so many calories per 100 g", and 100 g of cooked chicken breast is more chicken than 100 g of raw, while 100 g of cooked rice is much less rice than 100 g of dry.
Two things do change the calories themselves, and both are worth logging separately: fat added for cooking (oil, butter) and fat that drips away from fatty cuts. Add the oil as its own entry; accept that a rendered cut logged raw is slightly over-counted.
In plain terms: the pan changes the weight, not the energy, so the weight you write down has to match the state the entry describes.
Pick one and match the label
Here is the same portion logged four ways. Suppose 200 g of raw chicken breast comes out of the pan at 150 g — a quarter of its weight lost as water — and suppose 100 g of dry rice cooks up to 300 g. The proportions are illustrations; your cut and your rice will differ.
| What you weighed | Which entry you used | What gets logged | Compared with the truth |
|---|---|---|---|
200 g raw chicken | raw entry | 200 g raw | Correct |
150 g cooked chicken | cooked entry | 150 g cooked = the same chicken | Correct |
150 g cooked chicken | raw entry | 150 g raw — three quarters of what you ate | Under-logged by 25% |
200 g raw chicken | cooked entry | 200 g cooked — a third more than you ate | Over-logged by 33% |
100 g dry rice | dry entry | 100 g dry | Correct |
300 g cooked rice | cooked entry | 300 g cooked = the same rice | Correct |
300 g cooked rice | dry entry | 300 g dry — three times what you ate | Over-logged by 200% |
100 g dry rice | cooked entry | 100 g cooked — a third of what you ate | Under-logged by 67% |
The rice rows are why this matters. For meat the crossed error is a quarter or a third of one food; for grains it is a multiple, because grains absorb more than their own weight in water. Someone weighing cooked rice against a dry-rice entry is logging three bowls for every one they eat.
Which basis to pick:
- Raw is more repeatable. Cooking loss depends on time, heat and cut; a raw weight against a raw entry has no such variable. If you weigh before cooking, you are done.
- Cooked is more practical when food is cooked in bulk or by someone else. It is just as correct with a cooked entry — search for the food with "cooked", "roasted" or "boiled" in the name and check that the entry is not the raw one wearing a different label.
- Read the basis on branded products. A label may be per 100 g as sold (dry pasta, raw sausages) or as prepared; it usually says which. The logging-accuracy page explains why a consistent choice, whichever it is, becomes a steady bias the trend absorbs, and why an inconsistent one does not.
Recipes and batch cooking
A pot of chilli or a tray of roasted vegetables defeats both methods at once: several ingredients, all changing weight differently, and portions of unknown fraction. The method that survives it:
- Weigh and log the raw ingredients once. Add them up: that total is the calories and macros in the whole pot, whatever happens in the oven. Include the oil.
- Weigh the finished dish once. Tare the empty pot beforehand, or weigh it after and subtract. Do not use the sum of the raw weights as the cooked total — water has left or entered, and the sum may not include everything.
- Log each portion as a fraction. A
300 gbowl from a1,500 gpot is one fifth of the pot, so one fifth of the total calories. Tomorrow's400 gbowl is400 ÷ 1,500of it.
Worked example, purely as arithmetic: raw ingredients add up to 2,400 kcal; the cooked pot weighs 1,600 g on the scale. Calories per cooked gram are 2,400 ÷ 1,600 = 1.5. A 350 g bowl is 525 kcal. If the pot had been logged by summing the raw weights (say 2,100 g), the same bowl would have been entered as 400 kcal — under by a quarter — because the water that boiled off was still being counted as food.
If the tool you log in does not have a recipe feature, the fraction method still works with a single custom entry: create one food called by the dish's name with the pot's total calories and macros per 100 g of *cooked* weight (150 kcal per 100 g here), then log bowls by grams.
The short version
Weigh cooked or raw — but match the entry. Cooking moves water, not calories: meat gets denser per gram, grains get lighter per gram. Cooked meat against a raw entry under-logs by roughly the water lost; cooked rice against a dry entry over-logs by a multiple. Raw is more repeatable, cooked is fine with a cooked entry, and for anything made in a pot: log the raw ingredients once, weigh the cooked dish once, log portions as a fraction.
Educational overview only — not medical advice. Zyra is a training and nutrition tracking tool; the rates, caps and floors on this page describe how the calculator behaves, not what any individual should do.