Ultrasound and skinfolds: operator dependence in practice

Ultrasound and skinfolds: operator dependence in practice — setting out what I have, and where I think it stops being reliable.

Maintenance rather than loss, which is the part of this that almost nobody writes about.

I have been at roughly the same weight for 5 months. The interesting questions are all different from the ones I had at the start, and the documentation here is much thinner on this phase.

I would like to compare notes with people who are further along, and I would like to know what the published evidence says about this phase specifically rather than by extrapolation.

Thank you for the correction. I have edited my earlier post with a note rather than silently, so the thread still makes sense to read. The error was mine and it was the kind that comes from remembering a figure instead of looking it up.

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 #45, because the follow-up matters more than the original answer.

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.

post #49 is right about the mechanism and I think understates the practical bit.

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

On post #54 — agreed on the reasoning, with one qualification.

Resting metabolic rate: body composition affects metabolic rate. As fat mass decreases and lean mass is maintained, metabolic rate is usually maintained better than with simple weight loss alone.

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?"

Picking up post #63: that is the part I would want checked first.

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