How nutrition facts are calculated

Nutrition facts are calculated from each ingredient's net weight (using catalog values per 100 g) and shown per serving and per 100 g of the finished dish. Components are handled recursively — the sauce's nutrition inside a shawarma is calculated from the sauce's own ingredients, not entered separately. On the public recipe page there's a "reference" feature — click any ingredient's amount and enter how much of it you actually have, and the whole recipe (including nutrition and cost) rescales proportionally.