Basal Energy Expenditure of Chinese Healthy Adults:Comparison of Measured and Predicted Values

Objective This study aimed to measure the basal energy expenditure(BEE)of Chinese healthy adults and establish an accurate predictive equation for this population.Methods In total,470 Chinese healthy adults had their BEE measured using the Cosmed K4b2 portable metabolic system.Multiple linear regression analysis was applied to develop new optimal equations for predicting BEE.The bias,accuracy rate,concordance correlation coefficient(CCC),and root mean square error(RMSE)were used to evaluate the accuracy of the predictive equations.Results There was a significant difference in BEE between males and females,with 5,954 kJ/d and 5,089 kJ/d,respectively.People living in rural areas expended significantly higher BEE(5,885 kJ/d)than those in urban areas(5,279 kJ/d).Previous equations developed by Henry,Schofield,Harris-Benedict(HB),and Liu overestimated the BEE of Chinese healthy adults.The new equations derived from the present study displayed the smallest average bias and RMSE from the measured basal energy expenditure(mBEE).The CCC of the new equations was higher than other predictive equations,but it was lower than 0.8.There was no significant difference in the accuracy rate among all predictive equations.Conclusions Sex and regional differences in BEE were observed in Chinese healthy adults.Neither the widely used previous predictive equations nor the one derived in the present study were accurate enough for estimating the BEE of Chinese healthy adults.Further study is required to develop more accurate equations for predicting the BEE of Chinese healthy adults aged between 20–45 years.

Measurement of the Thermic Effect of Food in a Chinese Mixed Diet in Young People

Objective To determine the thermic effect of food(TEF)in a Chinese mixed diet in young people.Methods During the study,the participants were weighed and examined for body composition every morning.The total energy expenditure(TEE)of the participants was measured by the doubly labeled water method for 7 days,and during this period,basal energy expenditure was measured by indirect calorimetry and physical activity energy expenditure was measured by an accelerometer.The value obtained by subtracting basal energy expenditure and physical activity energy expenditure from TEE was used to calculate TEF.Results Twenty healthy young students(18–30 years;10 male)participated in the study.The energy intake of the participants was not significantly different from the Chinese Dietary Reference Intake of energy(P>0.05).The percentage of energy from protein,fat and carbohydrate were all in the normal range.The intakes of fruits,milk and dietary fiber of the participants were significantly lower than those in the Chinese Dietary Guidelines(P<0.05).There was no significant difference in the body weight of the participants during the experiment(P>0.05).When adjusted for body weight,there was no significant difference in either TEE or basal energy expenditure between the male and female participants(P>0.05).In addition,there was no significant difference in physical activity energy expenditure and TEF between the male and female participants(P>0.05).The percentage of TEF in TEE was 8.73%.Conclusion The percentage of TEF in TEE in a Chinese mixed diet in young people was significantly lower than 10%(P<0.001).A value of 10%is usually considered to be the TEF in mixed diets as a percentage of TEE.