Macros & Physique Tracking

The nutrition page where the goal is body composition, not just "what am I eating." For general food logging see Nutrition Tracking — Cronometer & MyFitnessPal; for diet-specific apps (keto, plant-based) see Diet-Specific Apps; for the meal-plan layer that sits on top of macros see Meal Planning Apps.

The 2025-26 standout

• ★ MacroFactor — paid only ($72/yr or $12/mo); no free tier but worth paying for. Built by the Stronger by Science crew (Greg Nuckols, Eric Trexler). Algorithm uses your weight trend + actual food log to back out true TDEE and adjust macros weekly. Replaces the "cut at 2,000 cal flat for 12 weeks" guesswork with continuous adaptation. Honest about its assumptions; minimal upsells.
  • https://macrofactorapp.com

The pitch: every other tracker calculates TDEE once with a Mifflin-St Jeor equation, then never updates. Real TDEE drifts as you diet (adaptive thermogenesis is real). MacroFactor uses your actual energy balance vs weight change to back-solve TDEE every week. This is the right way to do it; nobody else has shipped it as well.

Other paid macro / coaching apps

• Carbon Diet Coach — paid; Layne Norton; similar adaptive philosophy; older codebase; loyal user base.
• Strongr Fastr — paid (~$10/mo); generates macro-targeted meal plans + grocery list; bodybuilder-flavored.
• RP Diet App — Renaissance Periodization; paid; Mike Israetel's brand; meal-template approach rather than free-logging.
• Avatar Nutrition — sunset; ignore.
• Eat This Much (paid + free) — overlaps; meal-planner-flavored rather than tracker-flavored. See Meal Planning Apps.

Free macro calculators (one-shot, not adaptive)

• ★ Stronger by Science Macro Calculator — free, web; same crew that built MacroFactor; gives you a starting macro target. Defensible defaults.
  • https://www.strongerbyscience.com/macro-calculator/
• Legion Athletics calculator — free; bodybuilder-leaning.
• Examine.com macro guides — free; reference-grade nutrition science.
• Kreuzer-Dunn / Helms calculators — academic.

Body composition tracking

• ★ Hume / Withings Body Comp / Renpho — bioimpedance smart scales; trends are useful, single readings are not. Track 7-day moving average, not Tuesday morning's number.
• DEXA scan, every 6–12 months — gold standard for fat / lean / bone mass.
• InBody scans at gyms — better than bathroom bioimpedance, worse than DEXA.
• Tape-measure waist — free; very high signal-to-noise.
• Progress photos — same lighting / same time of day / weekly. The most underused measurement.

Integrations

• MacroFactor ↔ Apple Health / Health Connect / Garmin / Fitbit — pulls weight + activity, pushes macros.
• Cronometer ↔ MacroFactor — no direct integration; you'll log in one or the other, not both.
• Trainerize / TrueCoach — coach-side platforms that integrate with macro apps for client check-ins.

What "good macros tracking" needs

• ★ Adaptive maintenance. TDEE shifts during a diet. Apps that don't adjust waste your time after week 4.
• ★ Honest weight smoothing. Daily weight is noisy; a Kalman / EWMA smoother is required, not optional. MacroFactor does this; most don't.
• Weekly readjustment, not daily. Macros that change every day train obsession. Weekly is the sweet spot.
• Maintenance phases as first-class. Most apps assume you're always cutting. Bulks and maintenance are the harder phases to track well.
• Refeed / diet-break support. A planned refeed shouldn't break your trend math.

IIFYM vs whole-food approach

• IIFYM ("If It Fits Your Macros") — flexible dieting; eat anything, hit your macro targets. MacroFactor / Carbon are designed around this.
• Whole-food template approach — RP Diet App, MealPrepPro; pick from a narrow set of "approved" meals. Less freedom, less cognitive load.
• The honest call: whichever you'll actually adhere to. The "best" framework is the one you'll do for 12 weeks.

Self-host / DIY

• No good FOSS macro app exists in 2026. Wger has a nutrition module but no adaptive engine.
• DIY: Cronometer or MFP for logging → CSV export → Python notebook with a Kalman filter on weight + EWMA on intake → re-target weekly. ~200 lines. Nerds-only.
• Tracking the trend, not the day: Happy Scale (iOS, paid + free) and Libra (Android, free) do good weight smoothing if your only need is the trend graph.

Pricing reality (mid-2026)

Pick this if…

• Default if you can stomach paying: MacroFactor.
• Cheaper, free macro starting point: SBS Macro Calculator + Cronometer free tier.
• Coached experience, willing to pay more: Carbon Diet Coach or RP Diet App.
• Whole-food template style: RP Diet App.
• You hate logging: weigh-in trend (Happy Scale / Libra) + a dietitian.
• Long-term physique work: any of the adaptive apps + DEXA every 6–12 months + waist tape weekly.