MacroFactor and Trendline answer different questions. MacroFactor sets calorie targets from what you eat, and its expenditure estimate needs your food log. Trendline asks you to log no food and reads the weigh-ins and body-composition readings already in Apple Health. MacroFactor also runs on Android; Trendline is iPhone only.
Trendline is an iPhone app that reads Apple Health. MacroFactor is a food-logging and coaching app by Stronger By Science Technologies. Neither company is affiliated with the other.
First, the honest part
MacroFactor is a serious, well-regarded app: a 4.8-star average across about 22,800 App Store ratings, first released in 2021, and updated in September 2026 (its App Store listing, checked October 2026). It runs on iPhone, iPad, and Android. Its weight trend is, in its own words, "a moving average of your weight data that places greater emphasis on more recent weigh-ins", and it fills gaps between weigh-ins by linear interpolation (MacroFactor help: Weight Trend). That trend drives its main feature: an energy-expenditure estimate calculated from your logged calories and the change in your trend weight, which then sets your weekly calorie targets (MacroFactor help: Expenditure). If you want a calorie coach that adapts to your real data, it is one of the most thoughtful options available.
The real difference: food logging
MacroFactor's expenditure estimate needs your food log. Its own help center names "partial nutrition tracking" as the method's one Achilles heel. That is an honest, documented trade-off: the coaching is only as good as the logging.
Trendline does not ask you to log food at all. It reads the weigh-ins and body-composition readings already in Apple Health, keeps every reading with its source, and shows the trend with its uncertainty stated, so you can see whether a loss, a build, or maintenance is actually holding. It does not set calorie targets, and its iPhone app has no TDEE feature; a separate free TDEE calculator runs in your browser on this site.
Side by side
| MacroFactor | Trendline | |
|---|---|---|
| Main job | Food logging and adaptive calorie and macro coaching | Reading weight and body-composition trends |
| Food logging | Central; the expenditure estimate depends on it | None |
| Weight trend | A moving average weighted toward recent weigh-ins, with gaps interpolated | Statistical trend with explicit uncertainty; declines to conclude when evidence is sparse |
| Energy expenditure | Estimated from calorie intake and trend-weight change | Not in the iPhone app; free browser TDEE calculator on this site |
| Apple Health | Imports weight; exports weight and nutrition | Reads weight and composition; writes only after an explicit action for that exact operation |
| Body composition | Body fat % can be entered with a weigh-in | Calculated fat and lean mass from paired readings, plus manual entry for values Apple Health has no type for |
| Phases | Goal setup with a projected timeline | Lose Weight, Build Lean, and Maintain as distinct phases, with a goal forecast |
| Devices | iPhone, iPad, and Android | iPhone only |
| Price | $11.99/month, $47.99 per six months, or $71.99/year; 7-day free trial; no free tier (App Store listing, October 2026) | $0.99/week · $3.99/month · $10.99/year · $34.99 lifetime |
Who should pick which
- Pick MacroFactor if you are willing to log what you eat and want an app to set and adjust your calorie and macro targets from that log, or if you need Android.
- Pick Trendline if you don't want to log food, mainly want to know whether your weight and composition trend is real, or want losing, building, and maintaining read as different jobs.
- Use both if you like: MacroFactor exports weight to Apple Health, and Trendline reads weight from Apple Health. Check that only one app is the source of each reading, so the same weigh-in isn't counted twice.
Try the idea
Both apps start from the same insight: a single weigh-in is noise, and the trend is the signal. Paste a few weeks of weigh-ins into the free weight trend calculator to see it with your own numbers.
Questions people ask
What is the difference between MacroFactor and Trendline?
MacroFactor is a food-logging and coaching app that sets calorie targets from what you eat. Trendline reads what your body measurements are actually doing, using the weigh-ins and body-composition readings already in Apple Health, and it does not set calorie targets.
Do I have to log food to use MacroFactor?
Its expenditure estimate needs your food log, and its own help center names "partial nutrition tracking" as the method's one Achilles heel (MacroFactor help: Expenditure).
Does MacroFactor work on Android?
Yes. MacroFactor runs on iPhone, iPad, and Android, while Trendline is iPhone only.
How does MacroFactor calculate its weight trend?
It is, in its own words, "a moving average of your weight data that places greater emphasis on more recent weigh-ins", and it fills gaps between weigh-ins by linear interpolation (MacroFactor help: Weight Trend).
Can I use MacroFactor and Trendline together?
Yes. MacroFactor exports weight to Apple Health, and Trendline reads weight from Apple Health. Check that only one app is the source of each reading, so the same weigh-in isn't counted twice.
Sources
- MacroFactor on the App Store (version 5.8.9: pricing, trial, ratings)
- MacroFactor help: Weight Trend (method, interpolation)
- MacroFactor help: Expenditure (intake and trend weight; partial logging)
- MacroFactor help: Connect Apple Health or Health Connect (import, nutrition export)
- MacroFactor help: Log your weight (body fat entry)
- MacroFactor goal features (projected timeline)
- MacroFactor newsletter, August 2024 (weight export to health platforms)
- MacroFactor on Google Play
Trendline is not affiliated with or endorsed by MacroFactor or Stronger By Science Technologies LLC. Facts above were verified against the linked pages on October 3, 2026; app stores change, so check the listing for current pricing.