Our Data & Methodology
Last reviewed: 15/06/2026 · Next scheduled review: 15/06/2026
This page explains exactly where our data comes from, how we calculate the figures you see, and the limits of what those figures can tell you. We publish this in full because a calorie site is only as trustworthy as its sources, and ours are all named below.
Two kinds of data, kept separate
Not all nutrition sources do the same job, and we’re deliberate about which we use for what:
- Food composition data: The actual calorie and nutrient numbers for a specific food.
- Dietary guidance & context: Recommended intakes and healthy-eating context that inform our guides and explanations, not the per-food figures.
Keeping these separate is how we avoid false precision. The World Health Organization doesn’t tell you the calories in a portion of king crab; the USDA’s composition database does.
Tier A: Where our calorie figures come from
| Source | Role on this site | Reference |
|---|---|---|
| McCance & Widdowson’s Composition of Foods (CoFID) | Primary UK source for generic foods; the UK’s official food composition dataset, published by the Food Standards Agency / Public Health England. | CoFID dataset |
| USDA FoodData Central | International reference and gap-filling for foods not in UK datasets, and for corroboration. | FoodData Central |
| Manufacturer & restaurant published data | Branded supermarket products and named takeaway/restaurant items, using official label figures declared under UK food-labelling rules. | — |
| British Nutrition Foundation | Supporting UK nutrition science used to sense-check and contextualise figures. | nutrition.org.uk |
Where UK and US figures differ for the same generic food, we prioritise the UK source.
Worked example. For a UK staple like porridge oats, we use CoFID. For an item with no UK composition entry, say, king crab clusters, we reference USDA FoodData Central and label the source accordingly. For a branded product, we use the manufacturer’s published figures.
Tier B: Dietary guidance & health context
These authoritative bodies inform our guides, our healthy-eating context, and the recommended-intake figures used in our calculators, not the calorie count of any individual food:
| Source | What it informs | Reference |
|---|---|---|
| NHS — Eat Well | UK national dietary guidance and healthy-eating framing. | nhs.uk/live-well/eat-well |
| Scientific Advisory Committee on Nutrition (SACN) | UK government nutrient reference values and dietary recommendations. | SACN |
| World Health Organization — Nutrition | Global dietary guidelines and public-health nutrition context. | WHO Nutrition |
| British Dietetic Association (BDA) | Evidence-based food fact sheets from UK registered dietitians. | BDA Food Facts |
| British Heart Foundation | Heart-healthy eating context. | BHF nutrition |
How we calculate the figures
Per 100g and per portion. Every food page shows energy per 100g (the standard comparison basis) and per one or more common UK portions, because “calories in a banana” is more useful than “calories per 100g of banana.” Portions follow recognised UK portion references and, for branded items, the manufacturer’s stated serving.
Energy values. kcal figures follow the energy values published in our source datasets, which are derived using standard Atwater energy conversion factors (the internationally used method for calculating food energy from protein, fat, carbohydrate and fibre). We report those published values rather than re-deriving them.
The calculator. When you combine foods and portions, we sum the per-portion energy values of your selections. The total is a straightforward arithmetic sum of the figures described above.
Rounding. Calorie figures are typically rounded to the nearest whole kcal for readability; small rounding differences from a manual calculation are expected and immaterial for everyday use.
Branded & takeaway foods (our UK focus)
These items are our differentiator, so we handle them carefully:
- We use the producer’s official published figures where available.
- Recipes and formulations change; we date pages and re-check high-traffic branded items periodically.
- Where a takeaway dish has no single official figure (e.g. an independent chippy’s fish and chips), we present a clearly-labelled representative estimate based on typical composition and portion size, never false precision.
Keeping data current
- Pages display a “last updated” date.
- Most-used foods and branded items are reviewed on a cycle.
- Label changes, reformulations and corrections are actioned as we become aware of them.
- Spotted something wrong or out of date? Report it; corrections are actioned promptly.
Who produces this data?
This site is built and maintained by Saidul Islam Khan Samir of The Khan Digital. I’m an SEO specialist and web developer, not a nutritionist; and I’ve built this site so that its trustworthiness rests on transparent sourcing from authoritative bodies, not on personal authority. Every figure traces back to the sources named on this page. Where a data point is an estimate, we say so.
The limits of our data (important)
- Natural foods vary: Two bananas are never identical. Published figures are averages.
- Portions vary: Your “bowl” may differ from our reference portion.
- Preparation changes calories: Frying, oils, and sauces materially change energy content; we state the preparation assumed.
- Branded formulations change: Always check the label on the actual product for anything critical (including allergens, which we do not provide).
These figures are a transparent, well-sourced guide for everyday decisions; information, not medical or dietary advice. Please read our Medical Disclaimer.
All datasets and guidance referenced above are the property of their respective publishers; we cite them for transparency and appropriate credit.