Estimating resting energy expenditure in severely obese patients with laparoscopic sleeve gastrectomy: normalized lean weight appears to be more accurate——A prospective observational study

The accurate estimation of energy requirements in severely obese patients poses a significant challenge. This study compared the measured resting energy expenditure (mREE) obtained using indirect calorimetry with the estimated energy target in severely obese patients who underwent laparoscopic sleeve gastrectomy. This study enrolled patients who underwent elective bariatric surgery for metabolic syndrome and were admitted to the ICU between September 2023 and October 2024 because of severe clinical complications. The mREE of the patients was assessed using indirect calorimetry. The study evaluated the predicted resting energy expenditure (pREE) based on the SCCM/ASPEN recommendations (pREEasn) and the pREE based on the ESPEN guidelines (pREEesn). For the ESPEN standard, use normalised lean weight (NLW) and lean body mass (LBM) rather than adjusted weight to calculate the corresponding pREE (pREEesn/nlw) and pREEesn/lbm. The final analysis incorporated data from 64 individuals who had encountered at least one severe clinical complication, with a BMI of 44.2 ± 6.0. Compared with mREE, the mean bias for pREEasn was 13.2% (95% limits of agreement (LoA), -4.1% to 30.5%), for pREEesn, -3.8% (95% LoA, -14.7% to 7.1%), for pREEesn/nlw, 2.1% (95% LoA, -8.7% to 12.9%),and for pREEesn/lbm, -25.1(-45.7 to -5.1) . The predictive accuracies within ±10% of the mREE were 35.9% for pREEasn, 85.9% for pREEesn, 93.8% for pREEesn/nlw,and 6% for pREEesn/lbm . The root mean square error and concordance correlation coefficient were 347.6 kcal/d and 0.4, respectively, for pREEasn; 134.6 kcal/d and 0.76 for pREEesn; 115.8 kcal/d and 0.82 for pREEesn/nlw, and 479.8 kcal/d and 0.17 for pREEesn/lbm. The pREEesn/nlw demonstrated improved predictive accuracy for mREE in severely obese patients who underwent laparoscopic sleeve gastrectomy.