Lose weight by standing at work? Not necessarily...
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Is work-related sedentariness a contributing factor to obesity? Research at the University of Fribourg is introducing new elements to the calculation of energy used while sitting or standing and its relationship to variations in body weight.
Some companies expect meetings in a standing position to be more efficient. But do they also have positive effects on body weight? (Image: Thinkstock)
What if reducing the time spent sitting at work could contribute to a reduction in the risk of illness and an increase in life expectancy? This is the question which the research team led by Prof. Abdul Dulloo of the Department of Medicine at the University of Fribourg asked themselves. Previous studies, which were based on a comparison between sitting and a combination of standing and moving about, implied that reducing the time spent sitting each day by three hours would enable an extension of life expectancy by about two years. Subsequently, even if the results obtained in those experiments were open to question and the variations were significant (from 0% to 20% in energy expended by a person when standing), people’s attention became focussed on strategies aimed at reducing the time spent sitting. One of these was to work standing up.
The researchers in Fribourg noticed that the calculations had been carried out on the basis of a very long time span which must therefore have involved some movement on the part of the subjects, and that the equipment used was not well suited to the task. This is why the Fribourg research team not only looked at the size of the changes in expenditure of energy between the two states, but most importantly the time curve involved. So they observed minute by minute the expended calories, the cardiac rhythm and the respiratory quotient of 22 young adults of normal weight and in good health who spent ten minutes in each of the two postures. In order to interfere as little as possible with the subjects’ metabolism they employed a method of indirect calorimetry via a ventilated hood adaptable to the changes in posture.
The results point to three phenotypes: a third of the participants showed almost no difference between the two postures; four of these only displayed signs of effort while standing; and lastly, based on the measurements taken in the sitting position, the remaining ten expended less energy during the second part of the time they spent standing, i.e. the last 5 minutes.
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Thus this study opens new perspectives on our understanding of the metabolic and psychomotor basis for the variability in expended energy when standing for a relatively short period of time. But it also puts in doubt the relevance of creating standing workplaces in order to increase the expenditure of energy with the aim of controlling weight. So are we going to see the tempting goal of losing weight at work reached one day?
Link to the complete article
Abdul Dulloo, Professor of Physiology, Department of Medicine, University of Fribourg, 026 300 86 24, email@example.com