Comparison of the accuracy of resting metabolic rate in children with simple obesity using calculation formulas and indirect respiratory calorimetry

Abstract

BACKGROUND: A prerequisite for planning a diet for weight loss in obese children is to determine the level of resting metabolic rate (RMR). The gold standard for estimating the daily energy consumption of rest is indirect respiratory calorimetry. However, given its high cost and labor intensity, various calculation formulas are widely used in clinical practice. AIMS: to determine the accuracy of resting metabolic rate estimated by calculation formulas and indirect respiratory calorimetry in children with simple obesity. MATERIALS AND METHODS: The study included 100 children aged 9 to 18 years, with a simple constitutional-exogenous obesity, which assessed the resting metabolic rate estimated by calculation formulas and indirect respiratory calorimetry. RESULTS: The Molnar formula most accurately estimates resting metabolic rate, comparable to the results of indirect respiratory calorimetry in 64% of cases. The Harris-Benedict and IOM formulas yield an accurate result in 53 and 51% of the cases, respectively. The least accurate result is shown by WHO formula (22%). The minimum mean difference between the calculated and actual basal metabolic rate in obese boys for the Molnar formula is 18 kcal (CI: -53 to 90, 95% LOA from -490 to 527), in girls: -0.7 kcal (CI) : -65 - 63, 95% LOA from -435 to 434). Attention is drawn to the large mean difference and wide spread of the boundaries of the agreement of the studied indicators in obese children. In the evaluation, depending on the degree of obesity, it is shown that the formula Molnar has the highest accuracy, however, in children with morbid obesity, the accuracy of the evaluation is significantly reduced. CONCLUSIONS: Indirect respiratory calorimetry is the preferred method of assessing resting metabolic rate in children with simple obesity.