Total energy expenditure (TEE) of young adults from urban South India: revisiting their daily energy requirement.

BACKGROUND/OBJECTIVES: Young Indian adults are at greater risk of overweight/obesity due to their high energy intake and sedentary lifestyle. Their energy requirement (ER) is based on their total energy expenditure (TEE) estimated from factorial method, which possibly overestimates their basal metabolic rate (BMR) and physical activity level (PAL). This study aimed to compare the accurately measured TEE with ER in young adults. Secondarily, to compare measured with predicted BMR and guideline PAL with that obtained from questionnaire and step counts.

SUBJECTS/METHODS: TEE was measured in 19 male adults (18-30 years), using the doubly labeled water technique, over 14 days. Indirect calorimetry was used to measure BMR, while the PAL was estimated by (a) the ratio of measured TEE and BMR, (b) step counts over 7 days measured using tri-axial accelerometers and (c) a physical activity questionnaire (PAQ).

RESULTS

The measured TEE (9.11 ± 1.30 MJ/d) was significantly lower than the ER using either the Indian (15.2%) or the FAO/WHO/UNU (11.9%, both p < 0.01) recommendations. The measured BMR (6.90 ± 0.65 MJ/d) was significantly lower than that predicted using the FAO/WHO/UNU equation (6.5%, p < 0.01) but not for the Indian equation. The estimated PAL from measured TEE and BMR (1.35 ± 0.18), and from accelerometers (1.33 ± 0.11) was significantly lower than PAL obtained from PAQ (1.53 ± 0.17) or the guideline of 1.53 for Indians.

CONCLUSIONS

The predicted BMR and PAL guideline value was higher than that measured in young Indian adults, resulting in a ~13% lower measured TEE. This emphasizes the need to revisit the guidelines for predicting ER for this population.