Author: Zuzana Spacirova
Obesity has become one of the leading public health problems worldwide. According to projections published in The Lancet, by 2050 six out of ten adults and one third of children and adolescents will be living with overweight or obesity (1,2). Traditionally, obesity has been defined using the body mass index (BMI). However, the criteria used to define obesity are not universal: in Europe, obesity is defined as a BMI ≥ 30 kg/m²; in China, as a BMI ≥ 28 kg/m²; and in Japan and South Korea, as a BMI ≥ 25 kg/m². This is because many Asian populations tend to have a higher percentage of body fat at the same BMI, greater accumulation of visceral adipose tissue, and a higher risk of metabolic diseases at lower BMI levels. This highlights the fact that obesity cannot be assessed using a single global standard, but rather must be adapted to the characteristics of each population.
The definition of obesity based on a BMI threshold, though seemingly simple, conceals a far more complex reality. For many years, obesity was largely regarded as the result of inadequate individual choices, such as poor dietary habits and insufficient physical activity. This reductionist view led to significant stigmatization of people with obesity, who were held almost exclusively responsible for their condition. Today, however, there is growing consensus within the scientific community that obesity is a complex, multifactorial chronic disease (3). Genetic, hormonal, metabolic, psychological, environmental, and socioeconomic factors all play a key role in its development, contributing to a shift in both social and medical perceptions of this condition.
In this context, advances in pharmacological treatment have marked a significant turning point. In recent years, new medications (GLP-1 receptor agonists) have emerged that act on appetite regulation and metabolic mechanisms, delivering more effective results than traditional treatments. Originally developed to treat diabetes, these drugs represent a promising tool within a comprehensive approach that also includes lifestyle changes and ongoing medical support. However, their use raises important questions regarding accessibility, cost, and the role they should play within healthcare systems.
In Spain, the debate surrounding these treatments is particularly relevant. Despite their effectiveness, the Interministerial Commission on Drug Pricing has rejected funding for weight-loss medications due to the budgetary impact they would have on the National Health System, although a new negotiation is expected (4). This situation opens up a broader discussion about the need to define a global strategy that prioritizes healthcare resources based on cost–benefit criteria, taking into account not only clinical outcomes but also the indirect and intangible impact of obesity on quality of life, leisure activities, and social stigma.
In conclusion, obesity is no longer understood as a simple individual problem but is recognized as a complex disease requiring a multidimensional approach. New pharmacological treatments offer promising opportunities, yet they also pose ethical, economic, and social challenges that must be carefully considered.
References
1. Ng M, Gakidou E, Lo J, Abate YH, Abbafati C, Abbas N, et al. Global, regional, and national prevalence of adult overweight and obesity, 1990–2021, with forecasts to 2050: a forecasting study for the Global Burden of Disease Study 2021. The Lancet. 2025;405(10481):813-38. doi:10.1016/S0140-6736(25)00355-1
2. Kerr JA, Patton GC, Cini KI, Abate YH, Abbas N, Abd Al Magied AHA, et al. Global, regional, and national prevalence of child and adolescent overweight and obesity, 1990–2021, with forecasts to 2050: a forecasting study for the Global Burden of Disease Study 2021. The Lancet. 2025;405(10481):785-812. doi:10.1016/S0140-6736(25)00397-6
3. World Health Organization [Internet]. 2025 [citado 25 de febrero de 2026]. Obesity and overweight. Disponible en: https://www.who.int/news-room/fact-sheets/detail/obesity-and-overweight
4. Diario Médico [Internet]. 2025 [citado 25 de febrero de 2026]. Sanidad rechaza financiaciones para «Mounjaro» y «Ozempic». Disponible en: https://www.diariomedico.com/medicina/empresas/sanidad-rechaza-financiaciones-mounjaro-ozempic.html
