Predictive equations commonly used in the clinic underestimate resting energy expenditure compared with whole-room indirect calorimetry in colorectal cancer survivors

: Background Accurate methods for estimating resting energy expenditure (REE) are important to ensure adequate nutritional treatment in colorectal cancer (CRC) survivors. Objective To determine the agreement between REE estimated by commonly used predictive equations and by whole-room indirect calorimetry (WRIC). Design This cross-sectional study included 31 CRC survivors (age: 53–78 years; mean (standard deviation (SD)) body mass index (BMI) 28.7 (4.28) kg/m 2 ), who underwent curative surgery. Body composition was measured by dual-energy x-ray absorptiometry (DXA). Predicted REE from equations in clinical use and derived from DXA and bioelectrical impedance analysis (BIA) were compared against REE measured by 30-min WRIC. Equations included Harris-Benedict, Mifflin-St. Jeor, FAO/WHO/UNU, Henry, Mifflin-St. Jeor DXA, and FAO/WHO/UNU BIA . Paired sample t-test, Lin’s concordance correlation coefficient (CCC) and Bland-Altman analysis were used to determine the agreement between measured REE WRIC and predicted REE. Accuracy was defined as the percentage of predicted REE values that fell within ± 10 % of REE WRIC . Results Mean (SD) REE WRIC was 1710 kcal/d (353), and respiratory quotient (RQ) was 0.79 (0.05). Most equations underestimated REE. On average, Harris-Benedict, Henry, and FAO/WHO/UNU BIA showed the best overall agreement with REE WRIC . However, these equations showed low accuracy with 65 %, 68 %, and 62 % of predicted REE values within ± 10 % of REE WRIC , respectively. Conclusions Most predictive equations tended to underestimate REE in CRC survivors compared with REE WRIC . The Harris-Benedict, Henry and FAO/WHO/UNU BIA equations showed both best accuracy and agreement with WRIC. They were still inaccurate, with individual variability for a relevant part of the sample. Future studies need to develop improved predictive equations for CRC survivors. Clinical trial registry number https://clinicaltrials.gov/study/NCT01570010?locStr=Norway&country=Norway&cond= ; Identifier: NCT01570010