Exercise reduces the number of calories burned at rest in people with obesity, according to a new study by researchers at the Shenzhen Institute of Advanced Technology (SIAT) of the Chinese Academy of Sciences and Roehampton University.
The study, published Aug. 27 in Current Biology, found that people who exercise burn fewer calories doing personal hygiene and therefore significantly reduce the amount of calories burned from exercise. This decrease in energy burned at rest was most pronounced in those with obesity and to a lesser extent in older adults.
An analysis based on data from 1,750 adults in the IAEA’s dual-tagged water database (www.dlwdatabase.org) showed that those with the highest BMI converted 51% of the calories burned during activity into calories burned at the end of the day. However, for people with a normal BMI, 72% of the calories burned during activity were included in the total expenses.
The researchers examined the effects of activity on energy consumption and how these effects differ between individuals.
“When most people take part in weight loss exercise programs, they lose some weight. Some people lose a lot, but some people who are not lucky actually gain weight, ”said Prof. John Speakman of SIAT, the study’s co-author.
The reason for these individual reactions are probably so-called compensation mechanisms. This includes eating more food because exercise increases our appetite, or reducing our spending on other components such as our resting metabolism so that exercise is effectively less costly.
“But we wanted to find out why some people show such compensation mechanisms and others don’t,” said Prof. Lewis Halsey from the University of Roehampton in Great Britain, lead author of the study. The analysis showed that two things dominate the amount of compensation. One of them is that older people compensate more. The other is obesity specifically; People with obesity reduce their resting metabolism when they are more active. The result is that for every calorie they spend on exercise, they save about half a calorie resting.
This is a cruel twist for those with obesity. For such people, losing weight with increased activity is likely to be much more difficult than it is for a lean person, whose compensation is much less and whose need to lose weight is much less.
“Around the world, national guidelines recommend a 500-600 calorie deficit from exercise and diet to lose weight. However, they do not take into account the reduction in calories burned in the most basic human functions, as the body compensates for the calories burned in exercise, ”said Prof. Halsey.
Prof. Speakman added: “This analysis with data from the DLW database shows that people’s energy budgets are not all the same. People who live with obesity can hold onto their fat reserves particularly efficiently, which makes weight loss difficult. “
Reference: “Energy Compensation and Obesity in Humans” by Vincent Careau, Lewis G. Halsey, Herman Pontzer, Philip N. Ainslie, Lene F. Andersen, Liam J. Anderson, Lenore Arab, Issad Baddou, Kweku Bedu-Addo, Ellen E Blaak , Stephane Blanc, Alberto G. Bonomi, Carlijn VC Bouten, Maciej S. Buchowski, Nancy F. Butte, Stefan GJA Camps, Graeme L. Close, Jamie A. Cooper, Sai Krupa Das, Richard Cooper, Lara R. Dugas, Simon D. Eaton, Ulf Ekelund, Sonja Entringer, Terrence Forrester, Barry W. Fudge, Annelies H. Goris, Michael Gurven, Catherine Hambly, Asmaa El Hamdouchi, Marije B. Hoos, Sumei Hu, Noorjehan Joonas, Annemiek M. Joosen, Peter Katzmarzyk, Kitty P. Kempen, Misaka Kimura, William E. Kraus, Robert F. Kushner, Estelle V. Lambert, William R. Leonard, Nader Lessan, Corby K. Martin, Anine C. Medin, Erwin P. Meijer, James C. Morehen, James P. Morton, Marian L. Neuhouser, Theresa A. Nicklas, Robert M. Ojiambo, Kirsi H. Pietiläinen, Yannis P. Pitsiladis, Jacob Plange-Rhule, Guy Plasqui, Ross L. Prentice, Roberto A. Rabinovich, Susan B. Racette, David A. Raichlen, Eric Ravussin, John J. Reilly, Rebecca M. Reynolds, Susan B. Roberts, Albertine J. Schuit, Anders M. Sjödin, Eric Stice , Samuel S. Urlacher, Giulio Valenti, Ludo M. Van Etten, Edgar A. Van Mil, Jonathan CK Wells, George Wilson, Brian M. Wood, Jack Yanovski, Tsukasa Yoshida, Xueying Zhang, Alexia J. Murphy-Alford, Cornelia U. Loechl, Amy H. Luke, Jennifer Rood, Hiroyuki Sagayama, Dale A. Schoeller, William W. Wong, Yosuke Yamada, John R. Speakman and the IAEA DLW database group, August 27, 2021, Current Biology.
DOI: 10.1016 / j.cub.2021.08.016