A research shows that taking other measures into account alongside BMI helps to identify more cases of obesity

Is the study of good quality? Are the conclusions supported by sound data?

“It is a robust study, involving more than 844,000 participants from four countries, including Spain. Its results support the view that combining measures of adiposity with clinical assessment allows for a better distinction to be made regarding prognosis. However, it does not yet prove that using this classification improves treatment or reduces complications. The proposal to adopt it universally requires further evidence.”

How does it fit in with existing evidence?

“It reinforces something we have been advocating for years: BMI is useful, but insufficient for assessing a person with obesity. Fat distribution and its impact on health are crucial. What is new is the provision of follow-up data supporting the distinction between clinical and preclinical obesity, although the debate on how to use it remains open.”

Are there any significant limitations?

“Yes. It is an observational study and clinical information was not collected in a standardised manner across all cohorts. Furthermore, the attribution of certain health conditions to obesity was estimated statistically, without individual confirmation. This means the progression figures must be interpreted with caution: the fact that a person does not develop clinical obesity according to these criteria does not mean they remain free from health problems.”

What are the advantages of incorporating other body measurements and organ function rather than just BMI?

‘BMI does not distinguish between fat and muscle, nor does it reflect where fat is accumulated. Measuring waist circumference and assessing organ function helps to better understand each patient’s situation. Two people with the same BMI may have very different risks and treatment needs.’

How important is it to distinguish between clinical and preclinical obesity?

"It can help to tailor the intensity of monitoring and treatment. When organ damage is already present, there is a greater urgency to act. When it is not detected, we must focus on prevention and assess individual risk. The ‘preclinical’ category should not be interpreted as the absence of risk, nor should it be used to delay appropriate treatment.”

Could this lead to over-diagnosis or over-medicalisation? What implications would it have for prescribing medication?

“There is a risk if a new diagnostic label automatically translates into a prescription. However, these criteria can also correct imprecise diagnoses based solely on BMI. The prescription of medicines must be based on the expected benefit, the risks and the patient’s circumstances. This study does not determine who should receive them nor does it alter their authorised indications.”

Are they applicable in routine clinical practice?

“Supplementing BMI with waist circumference and a clinical assessment is feasible and should form part of good care. The greatest challenge is to rigorously establish which abnormalities are due to adiposity and to do so using standardised criteria. Their incorporation requires training, time and straightforward protocols, without turning the assessment into an indiscriminate battery of tests.”

This is a high-quality article, as it evaluates a large number of patients from different countries. The analysis carried out provides solid evidence that body mass index, which is widely used in clinical practice, does not correctly classify patients with obesity, leading to overestimation or underestimation. It is proposed that additional measures be used, such as the waist-to-height ratio and other measures related to organ function, which provide a more accurate classification and enable a treatment strategy better tailored to each patient’s individual situation. These measures are easily applicable in routine clinical practice and would help to avoid the over- or under-diagnosis of obesity.

The study distinguishes between clinical and preclinical obesity, demonstrating that patients classified as having preclinical obesity have lower mortality rates and that only a small number of those with preclinical obesity progress to clinical obesity within 10 years. This classification would enable the establishment of a preventive treatment strategy for patients with preclinical obesity and help determine the urgency of treatment, without implying inaction in the management of these patients. However, the fact that organ function was not assessed using biochemical or molecular measures constitutes a limitation of the study and may lead to an underestimation of the true clinical status. In this regard, I believe that for the future of obesity classification, in addition to incorporating various anthropometric and body composition measures, it would be necessary to carry out biochemical and molecular measurements in order to adequately quantify organ function. In fact, there is an epigenetic memory in adipose tissue that indicates dysfunction in that tissue, and it is possible that this is not being adequately assessed in patients classified as having preclinical obesity, who may present biological abnormalities that we are not yet detecting using conventional diagnostic tools.

The major challenge is not merely to classify obesity more effectively, but to identify biological dysfunction at an early stage so that we can anticipate its complications and move towards truly personalised medicine.