Ingredient flags, with the reason attached

Contamination is a measurement. Lead in a protein powder is parts per billion, established by mass spectrometry, and it varies between production lots of the same product from the same factory. Two tubs on the same shelf can differ.

An image and a description contain none of that. A model looking at a shake can identify a shake. It cannot see the lot number, and if it could, it does not have the assay. So any app showing you a number for lead in your lunch invented that number — and an invented number that looks precise is worse than saying nothing.

Categories have histories, and those histories are public. Consumer testing has repeatedly found cadmium and lead in cocoa and dark chocolate. Rice takes up inorganic arsenic from soil and water more readily than other grains, which is why the FDA publishes an action level for infant rice cereal. Third-party testing programs keep finding detectable lead and cadmium in protein powders, with plant-based and chocolate-flavored products testing higher on average. Swordfish, shark, king mackerel and bigeye tuna accumulate methylmercury, and the FDA and EPA publish a joint advice list. Lead adulteration of some imported spices and traditional remedies has been documented by multiple state health departments.

None of that tells you about the specific thing in front of you. All of it tells you the question is reasonable, and that buying a brand which publishes third-party test results is a sensible response.

A flag is deliberately not a nutrient. A nutrient has a unit, a daily total and a goal line; a flag has none of those. It carries two things: what was found — “dark chocolate”, “whey protein isolate”, “aspartame” — and why it is being mentioned, in one sentence, in plain language.

No number, because a number implies a measurement. No score, because a score is a number wearing a costume. Flags come at two volumes: a note is worth knowing and not worth worrying about, a caution is either something with a documented reason for care or, more often, something you told AIM you avoid.

Add the terms you care about — an additive, a sweetener you react to, an oil you would rather not eat, an allergen you are managing for someone else. When one appears in a meal, the flag says so and marks it as yours rather than as general advice.

That distinction matters. “You asked to be told about aspartame, and this has aspartame” is a different statement from “aspartame is dangerous”, and only the first is something an app is in a position to make.