What's actually being measured.

We score 11 nutrients with weights tuned by Varun Sharma ANutr (Registered Associate Nutritionist, Association for Nutrition · Registration No. 39977), against UK NHS reference intakes and standard plant-based-diet nutrition guidance: 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 assessment by a UK Registered Dietitian (RD, HCPC-registered), with an ICC > 0.90 acceptance bar. The methodology is led by Varun Sharma ANutr (AfN Registration No. 39977) with the dietitian collaboration named on the published paper. 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.