Bioimpedance and hydration: why the number moves

Lean mass loss during rapid weight reduction: depends on protein intake, resistance training volume, and total energy deficit. Adequate protein and maintaining training intensity both help preserve lean mass.

Maintenance phase: tracking body composition during maintenance (weight stable) is different from tracking during active loss. Changes are smaller and precision becomes more important.

Comparison to published data: the trials reported mean fat and lean mass changes. Individual results vary around that mean. Being above or below average is not a sign of something wrong.

I read post #19 twice before replying, because I had assumed the opposite.

DXA (dual-energy X-ray absorptiometry): the standard for body composition in research. Precision is roughly ±1 kg for lean mass. Two scans six months apart on the same machine with the same technician give you useful information. Two scans six weeks apart on different machines tell you about the machines.

Precision versus accuracy: the precision you need depends on what question you are answering. "Am I losing fat?" requires less precision than "Is my lean mass preservation within the expected range?"

Maintenance phase: tracking body composition during maintenance (weight stable) is different from tracking during active loss. Changes are smaller and precision becomes more important.

Coming back to post #41, because the follow-up matters more than the original answer.

Two things before anyone answers the substance.

First, the context in the first post is clear and specific. Second, the question is framed so that an answer can actually address it. Both are the norm here and both matter more than they sound.

Picking up post #48: that is the part I would want checked first.

Comparison to published data: the trials reported mean fat and lean mass changes. Individual results vary around that mean. Being above or below average is not a sign of something wrong.

This follows post #63 rather than contradicting it.

Visceral fat: DXA does not distinguish visceral (organ-associated) fat from subcutaneous fat. That distinction might matter but requires different imaging to measure.