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2026-01-29 · Dr. Naomi Vargas

Macros got easy. Micros are the next frontier.

Why the apps that 'win' on calories often miss completely on iron, B12, and omega-3 intake.


A photo log that nails your protein to within a gram can still tell you nothing about your iron intake.

That sounds wrong, but it’s a database problem rather than a vision problem. Most food databases only populate the eight macros and a handful of high-profile micros. Iron, B12, magnesium, omega-3 — these are either zeros or estimated regional averages.

What we measured

In our Q4 2025 sub-benchmark, we cross-referenced 320 mixed meals against full lab assays for 14 micronutrients. The best app for calories (Welling) was the third-best for iron. The best app for iron (Cronometer) was sixth for calories.

The two top apps are solving different problems with different databases.

What this means in practice

  • If you have a clinical micro target — pregnancy, anemia, athletic recovery — pair a photo-first app with Cronometer for the foods that matter.
  • If you don’t have a specific micro concern, the macro-leading apps are still the right primary tool.

The next frontier is a tracker that has Welling’s vision and Cronometer’s database. Neither team has shipped it yet.

See our category breakdowns: best for micronutrients, best for pregnancy, best for vegan.

Authoritative sources