“…Of the total studies, 35 studies were published from India, 70,71,85 –117 15 from the United States, 118 –132 2 from the United Kingdom, 133,134 and 1 each from Mexico, 135 New Zealand, 136 Thailand, 137 Brazil, 138 Japan, 139 and Sweden. 140 Most studies reported assessing direct measurement of respired gases for measuring oxygen consumption using indirect calorimetry techniques, whether through open circuit, closed circuit, bag system, or respiratory chamber method.…”