It was discovered by Lavoisier that energy metabolism is the outcome of a "combustion" relying on an element that he named "oxygen". This observation provided the basic rationale for the use of indirect calorimetry in the study of variations in energy expenditure of usual activities or to evaluate aerobic fitness. In kinesiology, oxygen consumption (VO2) is also used to measure mechanical efficiency (ME) as a proxy variable to reflect the efficiency of body energy expenditure. Recent research shows that ME is a valid predictor of the risk of excess body fat and hyperglycemia. The use of indirect calorimetry also revealed an interaction effect between sodium intake and aerobic fitness in females according to which high sodium consumers with a low fitness level display a substantial increase in adiposity. In a clinical setting, VO2 measurement thus contributes to improve the evaluation of the risk to develop obesity and diabetes.
Professor Angelo Tremblay obtained his PhD in Physiology in Université Laval, Quebec City, and is currently a professor in the Department of Kinesiology in this university. His investigations are mostly oriented towards the study of factors influencing energy balance in humans with the intent to improve obesity management. Recently, his research has been focused on the study of non-traditional determinants of obesity such as short sleep duration, low calcium/dairy intake, insufficient vitamin intake, suboptimal feeding behaviours, demanding cognitive effort and persistent organic pollutants. Over the last years, he has documented the impact of pre- and probiotics on energy balance and behaviours.