Scientists suggest revising the terms “obesity” and “overweight”. Scientists have found that even people with normal body weights can be prone to health problems that are traditionally associated with obesity.
The normal body mass index turned out to be an unreliable indicator of whether a person has excessively large stores of fat. This suggests that the concept of “obesity” should be redefined, scientists write in the journal JAMA Network Open.
“People with a normal body mass index, regardless of how much fat their body contained, were previously considered completely healthy. Our study showed that doctors should pay attention not only to body weight but also to its shape when assessing their health patients, “says Wei Bao from the University of Iowa (USA).
According to WHO data, about a third of the world’s population today is obese, and in some countries, such as Britain and the Middle East, more than half of the population is overweight. According to current forecasts, the number of people on Earth with extra pounds will reach 2.7 billion by 2025, with the proportion of people with extreme forms of obesity reaching the mark of 17%, and just carriers of excess weight – up to 46%.
Today, doctors and WHO experts determine the level of obesity using the so-called body mass index (BMI). It represents the weight of a person divided by the square of his height in meters. As a rule, this indicator is considered normal if it does not exceed 25, but at the same time remains at least 19 points. Excess weight is diagnosed between 25 and 30 points, and values below 18 indicate chronic malnutrition or anorexia.
Scientists suggest revising the terms “obesity” and “overweight”
Bao and his colleagues found that a “normal BMI” does not always guarantee that a person does not actually have extra pounds and does not suffer from the effects of obesity, observing the lives of approximately 150 thousand US residents aged 50 to 79 years old over the past two decades.
During these observations, doctors comprehensively observed changes in the health status and appearance of women, trying to understand what factors, in addition to body mass index, influenced their life expectancy, the likelihood of developing diabetes or cancer, as well as other diseases traditionally associated with obesity.
An analysis of the results of these observations revealed a curious picture. Many women with a relatively low BMI often suffered from diabetes, metabolic problems, bowel cancer, and other diseases traditionally associated with obesity.
All of them, as scientists discovered, were united by one thing – a large waist circumference. Despite the fact that these women were not considered obese, their belly and other central regions of the body contained large amounts of fat, which was offset by its absence in the limbs and other parts of the body.
This fat was extremely dangerous for women. Elderly residents of the United States, who had a normal BMI, but a large amount of fat, died on average 30% more often, and 20-25% more often became victims of cancer and heart and vascular diseases. An increase in weight leads to an increase in the development of inflammation, including in the brain tissues, which turned out to be associated with a decrease in the level of intelligence in people who have gained extra pounds.
On the other hand, obese ladies who did not have similar problems with fat accumulation in the central parts of the body, on the contrary, died 10% less than all their other peers, and similarly, they got fewer malignant tumors and circulatory problems.
All this, according to Bao, suggests that the concept of “obesity” should be redefined to include not only the body mass index but also the circumference of the waist and other parts of the body. In this case, it will more accurately reflect how extra pounds affect the quality and duration of a person’s life, the scientist concludes.