Small habits. Transparent methods.

What the numbers mean

1. Date-based priority

Days remaining is the difference between the item’s recorded date and today, using your selected household timezone. Activity dates retain the local date on which they were recorded. Items are ordered by the nearest date. “Use soon” means 0–3 days remaining. Past-date items are flagged separately.

days_remaining = item_date − today
use_soon = 0 ≤ days_remaining ≤ 3

A date is not a freshness measurement. The app does not observe temperature, packaging integrity or spoilage. You enter the label type: use-by or best-before.

2. Recipe ranking

Recipes receive three points for each matched ingredient due in 0–1 days, one point for a matched ingredient due in 2–3 days, and one tenth of a point for each other available ingredient. Past-date ingredients are excluded. Matching uses documented ingredient identities and compatible units, not nutritional or food-safety inference. Exact aliases keep plant drinks separate from dairy milk and prepared foods separate from dry ingredients. New meal plans must respect the saved household diet. Browsing allergen exclusions use listed ingredients only and do not certify safety.

priority = 3 × urgent_matches
         + 1 × soon_matches
         + 0.1 × other_matches

3. Food and value logged as used

Use and discard actions may cover all or part of an item. A transactional activity ledger subtracts the recorded quantity, proportionally allocates the remaining purchase cost and measured weight, and keeps the rest in your pantry. An idempotency key prevents duplicate submissions. Undo restores the exact recorded amounts and preserves the reversal in history. The dashboard covers a rolling 28-day window.

logged_weight = Σ weight of items marked used
logged_value  = Σ purchase cost of items marked used

These are self-reported totals—not verified money saved, avoided emissions or waste prevented. Missing purchase costs count as zero. Quantities use integer thousandths of their declared unit; costs use integer currency minor units. Each portion receives a rounded proportional allocation, and the final portion receives the remainder. Unknown weights for millilitres, pieces or portions are excluded from kilogram totals and disclosed separately. Undo excludes the reversed action from totals. Imported version 1 activity is retained but cannot be undone.

4. Meal planning and shopping quantities

Recipe quantities scale linearly by chosen servings. Inventory is matched by an editable ingredient key and the same declared unit. There is no inferred mass/volume or piece/weight conversion. For a weekly shopping list, a shared stock pool is allocated in date order, excluding food dated before the planned meal. The same stock is never counted twice. Missing quantities are consolidated by ingredient and unit. Generated lists are snapshots: regenerate after changes. Checked shopping items are not automatically added to inventory. A separate confirmation records actual purchase details and links new pantry stock; reversal is allowed only before that stock is edited or used. Cooking confirmation records explicitly selected batches and actual quantities in one transaction. Group undo restores all linked amounts together. Untracked ingredients and changed quantities are explicitly acknowledged; no leftovers or safe dates are invented.

New plans preserve an immutable recipe snapshot. Earlier plans use a clearly labelled baseline captured at upgrade because their original recipe revision was not recorded. Shopping uses the saved version and excludes plans already recorded as cooked. Recipe notes and feedback stay private to the kitchen; they are self-reports, not independent validation.

5. Weekly reflection

The last seven recorded calendar days are compared descriptively with the preceding seven. A missing log is not zero waste. Reasons and repeated discarded names produce simple rule-based suggestions, not diagnoses or causal claims.

6. Household measurement and pilot mode

Quick waste logs cover food never entered into inventory. Do not also log the same discard through pantry activity. Weighed, estimated and unknown weights remain separate, as do edible food, inedible scraps and mixed waste. For an inventory discard, a proportional weight allocation is an estimate; a weighed waste observation requires a separate scale reading. Existing older records are not retroactively certified as weighed.

The optional pilot records fixed baseline and follow-up periods, daily household occupancy, meals and unusual circumstances. Only confirmed days with exclusively weighed edible waste (or explicitly confirmed zero waste) contribute to the weighed rate. Away, missing, unconfirmed, estimated, unknown and mixed-waste days do not contribute. Adding or reversing waste invalidates the affected daily confirmation. Rate = edible weighed grams ÷ 1000 ÷ eligible person-days × 7. Percentage change is withheld until both periods have finished with complete eligible-day coverage and a positive baseline. This is descriptive self-measurement, not a randomized controlled trial, and there is no automated statistical significance or causal claim.

7. Shopping quantity suggestions

Suggestions require at least three recorded use days spanning at least fourteen calendar days within the last twenty-eight days. Recorded use divided by observed calendar days is scaled to seven days, then same-unit in-date stock and unchecked shopping are subtracted. Missing logs can underestimate need. Suggestions do not replace meal planning and never add purchases automatically.

8. A proposed controlled waste-reduction evaluation

For a future pilot, collect measured household discard weights during a baseline and an equal-length follow-up period. Account for changes in household size, meals eaten at home and missing observations.

observed_change_% = 100 × (baseline − followup) / baseline

This percentage is undefined when baseline is zero. An observed change alone cannot establish that the app caused it. A comparison group and a pre-specified analysis would strengthen evaluation.

What is—and isn’t—validated

The application implements deterministic arithmetic and date rules. We have not established that these rules predict spoilage or reduce household food waste. No pilot results, accuracy scores or causal effectiveness claims are presented here.

Recipe library and healthy-eating boundaries

The library includes 42 editorial cooking ideas across breakfast, main meals, salads/sides, soups, snacks, desserts and drinks. Vegetarian here excludes eggs; egg, chicken and fish dishes are separate categories. Food-group labels describe ingredients, not nutritional adequacy. No calories, nutrition scores, disease-specific suitability or clinical benefit is claimed. Recipes have not been independently kitchen-tested. Serving quantities scale, but cooking times and safety checks do not scale linearly.

Allergen exclusions apply only to listed ingredients, not optional additions, brands, cross-contact or every possible allergy. A recipe with no identified listed allergen is not certified allergen-free. Week summaries count planned dishes, not food actually eaten.

References for further reading

• UNEP Food Waste Index Report 2024 — global food-waste measurement context; not a validation of this product.
• UK Food Standards Agency: best-before and use-by dates — general label guidance; follow applicable local advice.
• WHO: Five Keys to Safer Food — general handling guidance.

• WHO: Healthy diet — general variety, moderation and food-group guidance, not endorsement of these recipes.
• FoodSafety.gov: safe minimum internal temperatures — thermometer guidance for poultry, fish, eggs and leftovers.
• UK Food Standards Agency: home food fact checker — storage and rice-reheating guidance. Follow applicable local advice.

Image credits

The shaded food and kitchen illustrations are original SVG artwork authored for SmartFood Saver. They are stylised illustrations, not food-safety assessments or exact photographs of the recipes.

Salad photograph: Salad Bowl, Public Domain Pictures. Used as illustrative imagery, not a photograph of a recipe produced by this app.

Methods version 2.0 · November 2026. Changes should be versioned before making comparisons across releases.