Energy balance

Using a preceding 24-hour calorimeter stay (Prestudy Day) to estimate energy expenditure is the most accurate method for achieving 24-hour energy balance in subsequent assessments, significantly outperforming regression equations based on anthropometrics, body composition, or resting/sleeping metabolic rates.

If you are conducting precise metabolic research requiring strict energy balance, using a subject's own 24-hour energy expenditure from a prior stay in a calorimeter is the gold standard for predicting their needs. While less accurate methods like Harris-Benedict or RMR-based equations exist, they introduce significant error. Use these simpler methods only if resources for a prestudy calorimeter stay are unavailable, understanding that prediction accuracy will be lower.