Relationship between energy expenditure, expressed as the physical activity index, and body weight at low physical...

The physical activity index, PAI, is defined as the energy expenditure, EE, divided by the resting metabolic rate, RMR. An expression for the body weight dependency of PAI, ie, dPAI/dBW = K, is derived. Numerical values for this coefficient were calculated on the basis of six published papers using whole-body calorimetry with observations over 24 h. It was found to be around -0.0022 per kg body weight difference in the PAI range between 1.25 and 1.70.