Say what you need — 400 kcal and 20 g of carbohydrate, for instance — and we will show you which products a portion of fits, how many grams to eat and what it costs.
Nutrition is declared per 100 g or 100 ml, so for each product we pick the portion that comes closest to every value you set at once. We do not fit the portion to one figure and check the rest against it: hitting the calories exactly and overshooting the carbohydrate threefold is a worse answer than being slightly out on both.
Every target carries equal weight regardless of its size — otherwise 400 kcal would drown out 20 g of carbohydrate simply for being the larger number. Portions nobody would actually eat are left out: no 3 g of oil, and no 4 kg of cucumber.