Predicted Total energy expenditure (pTEE) method

The pTEE method was originally developed by McCrory et al. [19]. Briefly, rEI is compared with pTEE using a TEE prediction equation based on DLW. Huang et al. [20] modified the method by comparing rEI with estimated energy requirements (EER), which are derived from TEE prediction equations from the Institute of Medicine based on a DLW [36]. The following equations are used for individuals aged 19 years or older:

Men with BMI 18.5–24.9 kg/m²:

where PAL_coefficient = 1 if sedentary, PAL_coefficient = 1.11 if low active, PAL_coefficient = 1.25 if active, and PAL_coefficient = 1.48 if very active.

Women with BMI 18.5–24.9 kg/m²:

where PAL_coefficient = 1 if sedentary, PAL_coefficient = 1.12 if low active, PAL_coefficient = 1.27 if active, and PAL_coefficient = 1.45 if very active.

Men with BMI ≥25 kg/m²:

where PAL_coefficient = 1 if sedentary, PAL_coefficient = 1.12 if low active, PAL_coefficient = 1.29 if active, and PAL_coefficient = 1.59 if very active.

Women with BMI ≥25 kg/m²:

where PAL_coefficient = 1 if sedentary, PAL_coefficient = 1.16 if low active, PAL_coefficient = 1.27 if active, and PAL_coefficient = 1.44 if very active.

Similar to the revised-Goldberg method, the pTEE method estimates confidence intervals for the ratio (rEI:EER), and 1.0 or 2.0 SD cut-off points are calculated. However, to compare with the revised-Goldberg method, 2.0 SD cut-off points were used in the present study, with the following equation:

where CV_rEI is the intra-individual variation in rEI, d is the number of dietary assessments completed, CV_EER is the error in the equations for EER, and CV_mTEE is the day-to-day biological variation and the measurement error for TEE based on the DLW method [37].

Based on suggestions from Huang et al. [20], the following values were used in the above equation: CV_EER = 11.0%, CV_mTEE = 8.2%. Since the present study used an FFQ to assess dietary intake, the values for CV_rEI were 19.8% for women and 18.6% for men [21]. Since only one FFQ was completed and the input variable for the cluster analysis was the average daily rEI, d was set to 1 [21, 35]. To account for the skewness in the distribution of energy intake, the 95% confidence interval for rEI:EER was estimated on a logarithmic scale and cut-off points were exponentiated [22, 38]. The ratio (rEI:EER) was expressed as a percentage and individuals with (%rEI:EER) below, above, and within the cut-off points were identified as EI-UR, EI-OR, and EI-PR, respectively. The pTEE cut-offs used in this analysis were: lower = 0.79 and upper = 1.26 for normal weight, and lower = 0.63 and upper = 1.59 for overweight or obesity.