How MealPrep.org.uk works

How plans are built

Plans are assembled from a curated library of UK meals rather than written one at a time. Each meal carries a quantified ingredient list, a meal type, a diet classification, a preparation time and practicality tags. A plan is a selection from that library that satisfies the constraints attached to it: calorie target, goal, diet, supermarket orientation, budget tier and cooking effort.

A combination is only published when it can actually be turned into a usable seven-day plan — with recipes, calculated nutrition and a grouped shopping list. Combinations that cannot meet their own constraints are not shown rather than being filled with approximations.

Recipe methods are generated deterministically from the ingredient list using recipe-family rules, so a stir-fry is written as a stir-fry, a roast uses the oven, and a cold salad is not routed through a hot cooking step. The same input always produces the same method.

How calories and macros are calculated

The quantified ingredient list is the single source of truth. Calories, protein, carbohydrate, fat and fibre are calculated from those ingredients at full precision and rounded once, at the point of display. Any stored headline figure on a meal is a synchronised copy of that calculation, never an independent number.

• Ingredient lines are parsed into a quantity, a unit, a food name and any raw or cooked qualifier.
• Quantities are converted to grams, millilitres or a food-specific count weight. Tablespoons and teaspoons use food-specific densities where treating them as water would be materially wrong — oils, honey and nut butters, for example.
• Raw and cooked foods are separate records. Dry grains never borrow cooked values and cooked quantities never borrow dry values.
• Values are summed with decimals intact and rounded once to whole units. Day totals sum the displayed meal values; weekly figures average the seven days.
• Water, herbs, seasoning and garnishes only contribute zero when the ingredient explicitly says it is excluded from the estimate. Oils, sauces and dressings are always counted.

Carbohydrate is available carbohydrate using the UK convention, which excludes fibre; fibre is reported separately. Sugars, saturated fat and salt are not calculated, so the site does not display them rather than showing a guess.

These are estimates of edible ingredient weight. They do not model cooking losses, drained weight beyond what an ingredient states, bioavailability, or how accurately you measure a portion in your own kitchen.

Where the nutrition data comes from

The site uses a local reference set of 230 canonical food records with reviewed aliases. Every record has explicit values for each stored macro — no macro is inferred from calories or from another macro, and no value is produced by fuzzy-matching an unfamiliar food to a vaguely similar one.

Records are sourced, in order of preference:

• The UK Composition of Foods Integrated Dataset (CoFID) where a suitable deterministic match exists.
• USDA FoodData Central where CoFID has no suitable match.
• A representative current UK manufacturer or retailer nutrition panel for branded-style products such as prepared sauces and dressings.

These mappings are stored locally. Neither the site build nor any page you load depends on an external nutrition service, so figures cannot silently change underneath a plan you have saved.

What a “1,500 calorie plan” means

A calorie label describes the target the plan is built around, not a promise that every day lands on that exact number. Real meals come in real portions, and forcing each day onto an exact figure would mean inventing portion sizes nobody would cook.

Instead, a plan only earns a calorie label when it meets a stated tolerance:

• Its seven-day mean is within ±3% of the stated target.
• Every individual day is within ±7.5% of the target.
• A protein target must be within ±5 g or ±5% on average, whichever is larger, and every day within ±10%.
• A high-protein label requires at least 20% of the plan’s calculated energy to come from protein.

If any ingredient, unit or serving yield cannot be resolved, the plan becomes ineligible for that claim and is rejected rather than published with guessed numbers.

One consequence worth knowing: a plan viewed on its own can show a slightly different calorie figure for the same recipe than the same recipe inside a plan, because portions are scaled to hit the plan’s daily target. That is the scaling working, not an error.

How shopping lists are built

A shopping list is generated from the plan’s own ingredient quantities. Identical foods are combined across the week, units are normalised so the same ingredient does not appear twice in different measures, and items are grouped into supermarket sections.

The list shows the quantity the plan uses. It is not a pack list: you cannot buy 192 ml of sauce or three-fifths of a bag of spinach, so expect to buy whole packs and have some left over. Small amounts of salt, pepper and water are not itemised.

What a supermarket-specific plan means

A supermarket-oriented plan is built around the kind of shop that retailer supports well — the ranges it is known for, the staples it reliably carries, and how its own-brand pricing tends to behave. Iceland plans lean on freezer-friendly components; Aldi and Lidl plans lean on a shorter list of low-cost staples; Tesco, Asda and Sainsbury’s plans assume broader ranges and easier substitutions.

It does not mean we have checked today’s stock, or that every ingredient maps to a specific product code in your local store. We do not hold live retailer data, so a supermarket-named plan is a shopping approach, not an availability guarantee. Every ingredient is a common UK supermarket item that can be substituted.

How cost estimates work

Weekly costs are planning ranges, not basket quotations. Generated plans use four one-person weekly tiers, which scale when you add household portions:

The estimate assumes a seven-day shop using common UK own-brand ingredients. It:

• is not connected to any live retailer pricing;
• does not guarantee a checkout total, delivery fees or membership prices;
• does not guarantee stock, promotions, loyalty pricing or a particular pack size;
• does not separately price salt, water or negligible seasoning, and does not subtract what you already have in the cupboard;
• cannot model pack-size leftovers, waste or regional price differences exactly.

A small number of older editorial plans carry a separately reviewed supermarket range with the date it was checked. Where that date is shown, it is the date of that check — prices will have moved since.

How diet filters are decided

Vegetarian, vegan and pescatarian classifications are applied to each meal from its actual ingredient list, not from its name, and an automated check runs across the whole library on every release. A meal cannot be labelled vegan if any ingredient resolves to an animal-derived food, and high-confidence incompatibilities block the build rather than producing a warning somebody has to notice.

The limitation is the same one that applies to cost and allergens: the site models generic foods. Where a real product’s suitability depends on the specific brand — some stocks, sauces, cheeses and dressings do — the classification reflects the ordinary UK form of that ingredient, and you should check the label if a specific product matters to you.

Allergens: what we can and cannot tell you

UK law requires 14 allergens to be declared when they are used as an ingredient. Every food in our reference set has been mapped against that list, so a plan can tell you which of the 14 appear in its ingredients:

• Celery
• Cereals containing gluten
• Crustaceans
• Eggs
• Fish
• Lupin
• Milk
• Molluscs
• Mustard
• Tree nuts
• Peanuts
• Sesame
• Soybeans
• Sulphur dioxide and sulphites

Where an allergen genuinely depends on the product you buy — stock cubes, protein powder, granola, sauces — it is shown as check the label rather than asserted either way.

We do not make allergen-free claims, and you should not read the absence of an allergen as one. We work from generic ingredient names. We cannot see which brand you buy, whether a manufacturer has reformulated a product, or whether a food was made in a factory that handles other allergens. Cross-contamination cannot be inferred from an ingredient name at all. If you are allergic or intolerant, the label on the product in your basket is the only reliable source — see the Food Standards Agency’s allergy and intolerance advice.

Food safety and storage

Meal prep and food safety pull in opposite directions, so the site follows current UK public-health guidance rather than what would be most convenient for a weekly plan. In particular, a seven-day plan is not an instruction to cook everything on Sunday and refrigerate it until Friday.

• Cool cooked food and refrigerate it within one to two hours; keep the fridge between 0°C and 5°C.
• Eat refrigerated leftovers within 48 hours, or freeze them instead.
• Cooked rice is stricter: cool within one hour, use within 24 hours, and never reheat more than once.
• Reheat until steaming hot throughout — at least 70°C in the middle — and reheat only once.
• Defrost in the fridge, then treat the food as fresh and use it within 24 hours.

Sources: FSA — how to chill, freeze and defrost food safely, NHS — reheating rice.

Automation and human involvement

We would rather be plain about this than let you guess. Plan assembly, recipe-method wording, nutrition calculation, shopping-list aggregation and page generation are all automated and deterministic. That is what makes it possible to offer this many combinations, and it is why the same plan always produces the same numbers.

What is not automated:

• The meal library itself is curated, and its ingredient quantities are set by hand.
• Every nutrition record and alias is entered and reviewed manually against a named source.
• Recipe-family rules, diet rules and quality invariants are written and tested by a person after reviewing real output.
• Guides and editorial pages are written and edited, not bulk-generated.

What we do not claim: no recipe on this site has been physically cooked and photographed by us, no product has been bought and bench-tested by us, and no page has been reviewed by a dietitian, nutritionist or doctor. If you ever see wording on this site implying otherwise, it is a mistake and we would like to hear about it.

Quality checks before anything ships

Every release has to pass an automated gate before it can be deployed. It is not a spot check: it runs across the whole library, and a failure blocks the release.

• Nutrition audit — every ingredient occurrence must resolve to a known food with a valid unit. An unresolved ingredient fails the build.
• Dietary audit — every meal’s diet label is re-derived from its ingredients and compared with the label it claims.
• Plan audit — plan combinations are checked against their calorie and protein tolerances.
• Recipe invariants — checks that raw proteins get a cooking step, that a method only cooks ingredients the recipe actually has, that dishes needing liquid are given one, and that recipe families match their ingredients.
• Regression corpus — every defect we have fixed is kept as a permanent test so it cannot come back.
• Link, metadata, schema, accessibility and performance audits across every generated route.

Findings that need human judgement rather than a deterministic fix are tracked in an internal ledger until they are resolved, so they are not quietly forgotten.

What this site does not do

• It does not give medical, clinical or personalised dietary advice. Calorie targets are general planning figures, and the right intake for you depends on your body, activity, health and goals.
• It does not replace professional guidance if you are pregnant or breastfeeding, are managing a medical condition, have a history of disordered eating, or have been given a clinical diet to follow. Please speak to a GP or registered dietitian.
• It does not make allergen-free claims or account for cross-contamination.
• It does not quote live supermarket prices, stock or promotions.
• It does not store your plans on an account. Saved plans, shopping-list ticks and quiz progress live in your own browser and disappear if you clear site data.

Found something wrong?

Corrections that affect safety, nutrition or a plan’s usability are prioritised. Report a problem through the contact page or the feedback form, or email mealprep.org.uk@proton.me. Including the page URL and what looked wrong makes it much faster to fix.