01
What Corpus estimates
A guided check-in can produce a composite score, estimated body fat, estimated FFMI, and muscle-group context. These results are directional tracking signals—not diagnoses or laboratory measurements.
Corpus methodology
Progress tracking needs a method—not false certainty.
Corpus is designed to follow direction over time. It is not a medical device, does not replace a DEXA scan, and does not turn a photo into a clinical measurement.
02
Why consistent capture matters
Pose, distance, framing, and lighting can change what a camera records. Photo Match evaluates consistency factors to help you interpret the comparison without claiming to eliminate every source of variation.
03
Why trends matter more than a decimal
A single estimate can vary. Repeating the same process and reviewing several weeks gives more context than treating one number as exact truth.
04
The role of weight and FFMI
Logged weight adds context to the visual trend. FFMI relates estimated fat-free mass to height and can help separate “am I getting lighter?” from “am I building or preserving lean mass?”
05
The optional role of Apple Health
When you authorize access, Corpus uses signals such as sleep, HRV, resting heart rate, wrist temperature, and respiratory rate for recovery context. Photo-based tracking works without this connection.
06
When to use a clinical assessment
Use a qualified professional and clinical methods when a medical, nutrition, or health decision depends on the result. Corpus helps track the work between those assessments—it does not replace them.