. Author manuscript; available in PMC: 2024 Nov 1.

Published in final edited form as: J Ren Nutr. 2023 Apr 27;33(6):707–716. doi: 10.1053/j.jrn.2023.04.002

Table 2.

Indicators of Nutrient Balance, and Their Considerations

Indicator	Key Considerations

Reported dietary intakes	• Underreporting of dietary intakes⁹ biases assessment toward undernutrition
• 24-hour diet recalls	• Limited to detecting relatively severe nutrient deficits
• Food records	• Time-intensive to collect and analyze
	• Provides a snapshot of energy and protein adequacy on days of measurement
	• Requires skilled examiner
Recovery biomarkers	• Many sources of measurement error (e.g., nitrogen balance, sampling accuracy, urea losses in urine (nPNA))
• UUN
• nPNA	• Cannot distinguish low protein intakes from lack of protein in the diet vs. low overall energy intake
	• Provides a snapshot of protein adequacy on days of measurement
	• Multiple days of measurement rarely available, but generally needed to obtain accurate estimate
Δ Nutrition status (Table 2)	• Changes in body composition are more sensitive over longer periods of time (e.g., months)
• Anthropometric	• Vary in reliability for serial measurements
• Functional	• Key considerations of nutrition status indicators (Table 4)
• Concentration biomarkers

nPNA, normalized protein nitrogen appearance; UUN, urinary urea nitrogen; Δ, change.