Objective The present study aimed to evaluate the accuracy of the factorial method for estimating energy needs in individuals living in China.Methods Sixteen healthy female adults aged 22.1±1.2 years with a body mass index (kg/m 2) of 20.4±1.7 were selected as subjects.In free-living conditions,energy expenditure (EE) was determined by using the factorial method.At the same time,the doubly labeled water method (DLW) was also used to measure energy expenditure of the subjects and served as the criterion method.EE predicted by the factorial method (EE factorial) was compared with the simultaneous measurement of EE by the validated DLW method (EE DLW).Results There was excellent agreement between EE factorial (7.46±0.59 MJ/d) and EE DLW (7.64 ± 0.49 MJ/d),with a difference of-2.6±4.9% (-0.18±0.36 MJ/d).No significant differences were found between the two methods.EE factorial was highly correlated with EE DLW (r=0.795,P<0.001) and a good agreement for individuals was found by using the Bland and Altman test.Conclusion The factorial method gives satisfactory estimates of EE for both groups and individuals living in China.
LIU JianMinPIAO JianHuaSUN RuiTIAN YingYANG XiaoGuang
Objective Doubly labeled water (DLW) method is the gold standard for measuring total energy expenditure (TEE). We used this method to measure TEE in Chinese young men. Methods Sixteen healthy young men age 23±1 years with body mass index 22.0±1.4 kg/m 2 were recruited. TEE was measured by the DLW method, and basal energy expenditure (BEE) was determined by indirect calorimetry. We also conducted 24-h activity, energy balance and factorial approach to estimate energy requirements of the subjects. Results TEE of subjects by DLW method was 9.45±0.57 MJ/day (2258±180 kcal/day). The 24-h activity was 10.80±0.33 MJ/day (2582±136 kcal/day). The energy requirement, derived from energy balance observations, was 9.93±1.32 MJ/day (2373±315 kcal/day). The BEE of 6.65±0.28 MJ/day (1589±67 kcal/day), calculated by the adjusted Schofield equation, was significantly higher (P<0.001) than that measured by indirect calorimetry, 5.99±0.66 MJ/day (1433±158 kcal/day). The TEE derived from the factorial approach was 10.31±0.43 MJ/day (2463±104 kcal/day). Conclusion The TEE of Chinese young men measured by the DLW method was about 10% lower than the current recommended nutrient intake (RNI), suggesting that the RNI for Chinese men maybe overestimated. Further studies are warranted to determine the value of the estimated energy requirement.
