Nearly two centuries ago , Adolphe Quetelet , a Belgian astronomer and mathematician interested in defining the characteristics of the “normal man,” began collecting data on body measurements from Western European men . He concluded that weight was roughly related to the square of height , which led to the formulation of the index that bears his name in 1833 .
However, Quetelet ‘s proposal was not recognized until 139 years later, in 1972. It was then that the ideologue of the Mediterranean diet , the American physiologist Ancel Keys, examined various height and weight indices and ruled that the Belgian scientist’s method was the best for predicting the thickness of body fat.
Renamed the body mass index (BMI), it remained a standard criterion for decades to come. This was probably due to its simplicity, and that is where the problems come from.
A highly questioned index
The BMI correlates with the risk of death at the population level. Established by the World Health Organization in its 1995 technical report , four cut-off points establish four categories: “underweight”, “normal weight”, “overweight” and “obesity”.
However, this classification is based on a Caucasian ideal and does not consider other factors such as gender, ethnicity, percentage of fat or muscle and other types of health risks or determinants. In addition, the limits are not as clear at the individual level .
In recent years, the measure has been so questioned that the American Medical Association issued a statement in June 2023 indicating that it has been used for racist exclusionary purposes and has caused serious historical harm.
Considering obesity as a multifactorial, chronic, recurrent and non-communicable disease, characterized by an abnormal and/or excessive accumulation of body fat that represents a risk to health, is an attempt to define it in a very general way . In addition, the diagnosis and management of this pathology have not been able to align with the clinical processes that are normally adopted in other chronic diseases.
The important role of abdominal fat
To address this issue, the European Association for the Study of Obesity (EASO) initiated and conducted a consensus process based on a list of 28 statements. Published on July 5 , it proposes a new framework for the diagnosis, classification and management of obesity in adults.
The document establishes that BMI alone is not sufficient as a diagnostic criterion, and that the distribution of body fat – and, above all, the accumulation of abdominal fat, strongly associated with cardiometabolic complications – is a better indicator.
Specifically, the new framework classifies waist-to-height ratio as a superior marker of risk . Furthermore, rather than relying solely on anthropometric measures, the clinical diagnosis of obesity should include a systematic assessment of medical, functional, and psychological impairments, such as mental health and eating behavior pathology.
A more realistic obesity classification
For adults of European descent, a person is now considered obese if he or she has a BMI ≥ 30 kg/m² or if he or she has a BMI of ≥ 25 kg/m² and a waist-to-height ratio greater than 0.5 in the presence of any medical, functional, or psychological complication . In any case , the waist -to-height ratio is a better marker of cardiometabolic risk than waist circumference or BMI alone.
In addition, the EASO document advocates the use of other tools such as assessments of muscle strength, performance and body composition for sarcopenic obesity (simultaneous presence of excess fat and decreased muscle mass), as well as regular screening for obesity-related cancers.
How to manage obesity
The EASO document also sets out four pillars for addressing obesity:
- Behavioral modifications such as nutritional therapy, physical activity, stress reduction, and improved sleep.
- Psychological therapy.
- Pharmacological treatment, as long as it is an adjunct to behavioral modifications in the following patients: with BMI ≥ 30 kg/m²; with BMI ≥ 27 kg/m² and a disease or complications related to obesity, and with BMI ≥ 25 kg/m² and a waist-to-height ratio > 0.5 in the presence of medical, functional or psychological deficiencies.
- Metabolic (focused not only on weight loss but also on improving associated metabolic conditions such as type 2 diabetes) and bariatric (surgical interventions) procedures in individuals with BMI ≥ 40 kg/m²; BMI ≥ 35 kg/m² and an obesity-related disease; and BMI ≥ 30 kg/m² and poorly controlled type 2 diabetes despite appropriate medical therapy.
The new European strategy makes treatment more effective and emphasises the need for a multidisciplinary and interdisciplinary team to address this chronic disease at an individual level.
Date: Published: 10 July 2024 00:25 CEST
Fuente: The Conversation
Note: Nutrigenomics Institute is not responsible for the opinions expressed in this article.
Image by Gerd Altmann on Pixabay
