In the Christmas season that we are, there are many who set themselves the goal of the new year to lose weight, and they think that the best way to do it is by joining the gym. And, although this is something beneficial for health and highly recommended, exercising does not seem to be enough to lose those extra kilos, according to a study by the International Atomic Energy Agency (IAEA).
As the authors have explained in the research, this method can be effective in some people, but not in others, since it seems that the calories expended through physical activity do not always increase the total lost by the body, which directly interferes in weight loss.
The analyzes were carried out using a nuclear technique that uses water enriched with two types of isotopes: oxygen-18 and deuterium. More than 7,600 people underwent this test in which they had to drink water with one of the two types of isotopes and then provided urine samples at seven and 14 days. This allowed knowing the total energy spent in a very specific way.
The results of the study showed that the measurements of calories burned that are recorded by devices such as smart bracelets or the screens of electric treadmills or stationary bicycles may not be the total amount expended and, therefore, may not translate into real weight loss.
People with obesity have more difficulty losing weight
Specifically, it was observed that people with a normal body mass index (BMI) (between 18.5 and 24.9) will compensate for the calories burned in exercise by 28%, which means that only 72% of the calories expended they will really be lost. This relationship increases with increasing weight and age, so that those with a higher BMI will only lose 51% of the calories expended during physical exercise. People with obesity have more trouble losing weight due to their bodies’ efficiency in retaining already stored fat.
People with a normal BMI will lose 72% of the calories indicated on the machine or on the activity bracelet, a figure that drops to 51% in those with a higher BMI
“There are many health benefits to be gained from being more active and exercising, but relying on exercise alone will not help you lose weight. If you increase activity, the body will compensate in other areas and reduce calories expended breathing, digesting, fidgeting, and generally maintaining body functions. Actually, this can add up to quite a bit,” said Alexia Alford, one of the authors of the research, which has been published in the journal Current Biology.
The technique used is not new, however, it has a high price and therefore small-scale studies of this type have not been carried out. Now the IAEA, in addition to the data it already has thanks to the UN database, wants to expand its knowledge with figures from Asia, Africa and Latin America, so in 2022 its experts plan to start a research project with information on athletes, runners, people with cancer and cerebral palsy and their calorie loss in low-income countries.
