Food data with
the assumptions visible.

The short answer: a nutrition log depends on three separate judgements: which food it was, what nutrition values apply to that food and how much was eaten. BestBody keeps entries editable because uncertainty in any one of those steps changes the result.

Source hierarchy

BestBody uses the UK government's Composition of Foods Integrated Dataset (CoFID) ↗ for UK reference foods and can use packaged-product information, including records from Open Food Facts ↗. CoFID represents reference foods; Open Food Facts is community-contributed; and a manufacturer can reformulate a product. No one source perfectly represents every brand, recipe or changed formulation.

The practical order depends on what is being logged:

1. For the exact packaged product, compare its current label with the matched product record.
2. For a generic or unbranded food, use an appropriate UK reference record and preparation state.
3. Use the user-confirmed weight, portion or recipe share to calculate the amount eaten.
4. Keep a user correction identifiable rather than presenting it as independently analysed data.

When sources conflict, the more specific current evidence for the food in hand usually takes priority. BestBody does not turn a disagreement into a falsely precise average. The entry can be reviewed and corrected.

Per 100g values and servings

Per-100g values provide a common basis for comparing foods. The amount logged is calculated from the food's values and the confirmed quantity eaten. For example, a 75g amount uses three quarters of the per-100g value. The result is only as reliable as both the source value and the weight or portion.

A labelled serving is not a universal portion. Brands can define different serving sizes, and the amount actually eaten may differ from the pack suggestion. BestBody therefore treats serving size as useful context, not proof of consumption.

Recipes, portions and yield

A recipe starts with each ingredient's source values and quantity. Those ingredient totals are combined, then allocated using the recipe's stated number of portions or its final measured yield. If the ingredient quantity, edible amount, final yield or number of servings is wrong, the per-portion result will also be wrong.

Cooking can change water weight and therefore values per 100g; preparation can also leave oil, sauce, peel, bones or other material outside the amount eaten. BestBody does not assume that a visual portion or an uncooked weight resolves all of those differences. Recording the preparation state and a measured cooked yield where practical gives a more useful estimate.

Rounding and apparent precision

Source labels, household measures and displayed totals can each be rounded. Unit conversions and adding several rounded ingredients can therefore create small differences between a pack calculation and a daily total. Extra decimal places do not make an uncertain portion more accurate, so BestBody treats nutrition totals as practical estimates rather than laboratory measurements.

Barcode logging: useful identifier, not verification

A barcode can locate a candidate product record quickly, but the code itself contains no nutrition values. Similar packs, regional versions and reformulations can leave a record out of step with the product in hand. Check the product name, brand, pack size, serving and per-100g panel, then edit the entry when the label differs.

Photo logging: an editable estimate

A meal photo can help identify visible foods and estimate portions. It cannot reliably reveal a hidden ingredient, cooking oil, recipe ratio, product formulation or exact weight. Similar-looking foods may also have different energy and nutrient values. Photo logging is therefore a starting estimate for review, not proof of ingredients or portion size.

Corrections and provenance

When an entry looks wrong, first confirm the food identity, then the source values, preparation state and amount. Correct the editable field that caused the difference rather than compensating elsewhere in the diary. Where relevant, BestBody retains source and time context so a manual change can be distinguished from a reference or product record. Concerns about public methodology or attribution can be reported through the contact page.

Known publication limits

BestBody has not published the precise CoFID release used for every reference-food record or a fixed refresh schedule for external food data. We therefore do not state a version or sync cadence here. A time-sensitive packaged-food value should be checked against the current label. See Data Sources for more about provenance and Open Food Facts licensing context.

General wellness boundary

BestBody provides general food logging and planning support. It does not diagnose a condition, prescribe a diet or provide medical nutrition therapy. Calories and nutrient estimates may be unsuitable for an individual clinical need. Anyone managing an allergy, eating disorder, pregnancy, medicine, diagnosed condition or other medical concern should follow advice from an appropriately qualified professional. BestBody must not be used to decide whether a food is safe for an allergy.

Related reading: What is CoFID?, Barcode Food Scanner, Photo Food Logging and Limitations.

Last reviewed: 12 September 2026.