Uses and limitations of the balance technique.
Level 5 - mechanism / opinion, no new human data
Narrative review / methodological commentary with no primary data
PubMed 3312697 · doi:10.1177/014860718701100511
What was done
This narrative review examined the methodology, sensitivity, and systemic sources of error in classical metabolic and nutritional balance techniques, with a focus on nitrogen balance assessment.
What was found
The abstract reports no empirical numbers or quantitative data. It highlights that although balance studies offer high precision for transient or short-term responses when diet and environment are strictly controlled, systemic errors consistently overestimate intake (e.g., food adhering to utensils) and underestimate output (e.g., unmeasured losses from sweat, skin exfoliation, hair/nail growth, saliva, menses, flatus, respiration, semen, and blood sampling), leading to erroneously positive cumulative balances.
Why it matters
It emphasizes the inherent methodological bias toward artifactually positive balances in metabolic nutrition research, requiring caution when interpreting cumulative retention data.
Limits
This is a narrative review with no primary data, systematic search protocol, or sample size reported. The abstract was truncated and provides no quantitative estimates of the magnitude of unmeasured losses.
Cited by
- contradicts Nitrogen balance studies used to establish the RDA for protein are prone to errors due to incomplete collection and overestimation of nitrogen losses.