What's actually being measured.

We score 11 nutrients with weights tuned by a registered dietitian: vitamin B12 (2.5), heme-iron equivalent (2.0), omega-3 EPA/DHA (1.8), iodine (1.8), zinc (1.5), DIAAS-adjusted protein (1.5), calcium (1.3), saturated fat (0.8), carbohydrates (0.8), sodium (0.5), vitamin C (0.4). Sodium gets a 1.5× penalty multiplier when the swap adds salt.

DIAAS (Digestible Indispensable Amino Acid Score) corrects raw protein grams for amino-acid completeness. Seitan scores 0.25, which means its 25 g of "protein" is functionally about 8 g once digestibility is accounted for. Quorn scores 0.93, close to chicken's 1.08.

Bioavailability multipliers reflect that plant non-heme iron is absorbed at ~40% the rate of animal heme iron, and plant α-linolenic acid converts to EPA/DHA at <5% efficiency. Both are factored into the score.

Macro and micronutrient data is sourced primarily from McCance & Widdowson's Composition of Foods Integrated Dataset (CoFID, 7th edition, 2021), published by Public Health England under the Open Government Licence (UK gold-standard). We supplement with USDA FoodData Central where M&W doesn't cover an ingredient (typically processed and imported items).

Cost figures are sampled monthly from Tesco, Sainsbury's, Asda, Morrisons, and Ocado per-100g pricing on own-label and cheapest mid-tier products. Each curated entry cites its source.

The web preview lets you search any of our 500+ most-popular curated swaps with a basic match-score view. Everything else is in the app: full nutrient breakdown, allergen filters, ingredient quantity tuning, saved-swap library, in-store packaged-product photo flow, recipe generation. iOS and Android, free at launch.

We're not running ads or selling data. The honest reason the web is limited: generating fresh swaps requires AI compute that's unsustainable at scale for a free anonymous product. The app uses on-device models so we can keep it free.

OptVeg's algorithm is being prepared for clinical validation against registered-dietitian assessment, with an ICC > 0.90 acceptance bar. Every recommendation produced by the app is logged with full algorithm version + weight snapshot, so the validation paper can reconstruct exactly what was scored.

Until the validation study completes, the algorithm is research-grade. Sufficient for general guidance, not clinical prescription. If you're managing a medical condition (kidney disease, severe iron-deficiency, etc.), consult your GP or dietitian.