Overweight does not indicate a higher risk of death, according to a study – 07/06/2023 – Equilíbrio

People who are overweight, but not considered obese according to BMI (body mass index), do not have a high risk of death, according to a new study published this Wednesday (5), which highlights the limitations of BMI as a metric. in medicine.

The results, published in the journal Plos One, come at a time when the population of rich and poor countries continues to gain weight. In the United States, more than 70% of adults are overweight or obese.

The index, first described by a Belgian mathematician in the 19th century, is calculated by dividing a person’s weight by the square of their height.

This metric is increasingly being seen as a limited tool to measure people’s health.

“I think what people need to understand from this is that, by itself, BMI is not a great indicator of health,” study lead author Aayush Visaria of Rutgers University in New Jersey told AFP.

The specialist says that additional metrics, such as waist circumference or tests to visualize bone density, body fat and muscle mass, should be used for a more complete interpretation.

Excess fat is still a high risk factor for some conditions, including heart disease, diabetes and stroke.

“I’ve seen patients with the same BMI, but with huge metabolic differences and health implications, so I wanted to investigate further,” added Visaria.

Previous studies of the relationship between weight and death rate have had inconsistent or uncertain results and have focused primarily on non-Hispanic white adults.

In this new research, Visaria and co-author Soko Setoguchi drew on data from the US National Health Survey of more than 550,000 American adults between 1999 and 2018, as well as the 2019 National Mortality Index.

The researchers calculated BMI based on participants’ reported weights and heights and collected demographic data, factors such as smoking or physical activity, health conditions and even access to medical services.

More than 75,000 people included in this study died during the research period.

After adjusting for other variables, the results showed that people with a BMI between 25 and 30, classified as overweight, did not have a higher risk of death compared to individuals whose BMI was between 22.5 and 24.9.

However, the risk of death increased significantly among those with a BMI of less than 20 and among those with a BMI of 30 or more who were classified as obese.

For example, a person with grade 3 obesity, that is, with a BMI of 40 or more, but who has never smoked or has no history of cardiovascular disease or skin cancer, was more than twice as likely to die compared to a equivalent person with an average BMI.

The average age of participants was 46 years, with equal participation between genders and 69% of non-Hispanic whites. Among them, 35% had a BMI between 25 and 30, and 27.2% had a BMI equal to or greater than 30.

“It’s a large study with a representative sample,” George Savva, a biostatistician at the Quadram Institute in the United Kingdom, told AFP.

“As far as I can see, the authors have done a good job of looking at the relationship between mortality and baseline weight status.”

Savva said it may be the case that overweight-related illnesses are being better controlled now, such as high blood pressure and high cholesterol.

“The relationship between weight and mortality can be expected to change over time, and this is potentially what is being shown here,” he said.