Comparison of total energy expenditure between the farming season and off farming season and accuracy assessment of estimated energy requirement prediction equation of Korean farmers

BACKGROUND/OBJECTIVES: The purposes of this study were to compare total energy expenditure (including PAL and RMR) of Korean farmers between the farming season and off farming season and to assess the accuracy of estimated energy requirement (EER) prediction equation reported in KDRIs. SUBJECTS/METHODS: Subjects were 72 Korean farmers (males 23, females 49) aged 30-64 years. Total energy expenditure was calculated by multiplying measured RMR by PAL. EER was calculated by using the prediction equation suggested in KDRIs 2010. RESULTS: The physical activity level (PAL) was significantly higher (P < 0.05) in the farming season (male 1.77 ± 0.22, female 1.69 ± 0.24) than the off farming season (male 1.53 ± 0.32, female 1.52 ± 0.19). But resting metabolic rate was significantly higher (P < 0.05) in the off farming season (male 1,890 ± 233 kcal/day, female 1,446 ± 140 kcal/day) compared to the farming season (male 1,727 ± 163 kcal/day, female 1,356 ± 164 kcal/day). TEE (2,304 ± 497 kcal/day) of females was significantly higher in the farming season than that (2,183 ± 389 kcal/day) of the off farming season, but in males, there was no significant difference between two seasons in TEE. On the other hand, EER of male and female (2,825 ± 354 kcal/day and 2,115 ± 293 kcal/day) of the farming season was significantly higher (P < 0.05) than those (2,562 ± 339 kcal/day and 1,994 ± 224 kcal/day) of the off farming season. CONCLUSIONS: This study indicates that there is a significant difference in PAL and TEE of farmers between farming and off farming seasons. And EER prediction equation proposed by KDRI 2010 underestimated TEE, thus EER prediction equation for farmers should be reviewed.