After the Christmas binge, many have started the year with the purpose of doing sports to lose weight. The bad news is that exercise is not enough to lose weight, since the body compensates for that burning of calories by reducing energy consumption, reveals a study in which the UN nuclear agency participates.
“By increasing exercise, the body compensates for the calories burned by limiting the energy used in basic functions such as breathing or digestion,” Alexia Alford, one of the authors of the study and a nutritionist at the International Atomic Energy Agency (IAEA), explains to Efe. .
In other words, following burning calories with sport, the body starts a kind of energy saving mechanism, which ends up reducing the weight loss effect of physical activity.
The work “Energy compensation and adiposity in humans”, recently published in the scientific journal Current Biology, has reached this conclusion using two isotopes, one hydrogen and one oxygen, as “markers” to analyze the calories that a person burns during one day. (Read here: 5 tips to fulfill the New Year’s resolution to exercise)
The researchers gave 1,754 people water with these two isotopes to drink and then analyzed their urine, their body characteristics and their basal metabolic rate, which acts as a counter for the energy expenditure of basic body functions, such as breathing.
Almost 30% of calories not burned
By subtracting that basal expenditure from the body’s total energy consumption, the researchers identified how many calories were burned doing sports.
The conclusion is that people with a body mass index between 18.5 and 24.9, considered normal, this compensation is 28%, that is, only 72 out of every 100 calories spent with physical exercise are transformed into calories “burned” and, therefore, in weight loss.
The results are more discouraging for people with a higher body mass index, in the overweight and obese categories, since that saving mechanism results in only half the calories being lost.
“For every calorie that very obese people – with a body mass index of 35 or more – spend exercising, the compensation can be up to 50%,” says Alford.
more difficult with age
For this reason, it is important to know how our metabolism works in order to carry out an activity plan or a diet adapted to each person.
And it is that this energy compensation system not only varies according to metabolism and weight, but also by age.
For example, from the age of 60 the metabolism slows down by 1% each year that passes, which means less energy is consumed and losing weight with sport also becomes more difficult.
The research does not seek to discourage those who in this new year have proposed to lose weight or adopt a healthier lifestyle. (It may interest you: Menstruating is not synonymous with stopping exercising)
“The results do not suggest that exercise is ineffective, physical activity has many health benefits,” says Alford.
Among these benefits, the reduction in mortality due to cardiovascular diseases, cancers or incident type 2 diabetes stands out, as well as an improvement in mental and cognitive health and a better sleep balance.
Balanced diet
Beyond exercise, Alford also advises reducing your intake of processed foods high in fat and sugar, and increasing your intake of fruits, vegetables, legumes, whole grains and nuts.
In addition, the IAEA nutritionist also recommends not smoking, reducing alcohol consumption and having a positive mental health.
“Losing weight in a healthy way consists of an ongoing lifestyle that includes long-term changes in both daily eating habits and physical activity,” he concludes.
