Exploring the impact of adult obesity in Spain: Insights from a systematic literature review

Background: Spain ranks among the European countries with the highest obesity prevalence, yet the evidence on the full spectrum of its impact has not been systematically consolidated. Methods: This was a systematic literature review (SLR) conducted to evaluate the epidemiological, clinical, humanistic, and economic impact of obesity in Spain. Embase® and MEDLINE® were searched for relevant publications from January 1, 2018, to August 17, 2025. Results: A total of 54 records reporting on 53 studies were selected for inclusion. These covered (1) Epidemiology of obesity in Spain (n = 24); (2) Patient characteristics and obesity management (n = 7); (3) Obesity-related complications (n = 13); (4) Humanistic impact of obesity (n = 10); (5) Economic burden (n = 7); (6) Perceptions and attitudes about obesity (n = 4); and (7) Local policies and recommendations (n = 7). The prevalence of obesity (defined as a body mass index [BMI] ≥30 kg/m 2 ) varied considerably according to study setting and methodology, ranging from 25% to 34% in primary care settings and from 11% to 22% in general population studies. The most frequent obesity-related complications included hypertension, dyslipidemia, type 2 diabetes, cardiovascular disease, and chronic kidney disease. Evidence suggested that people with obesity and overweight may have lower quality of life than those without obesity and overweight. The economic burden of obesity was high in Spain, with costs decreasing as BMI decreased. Included studies highlighted several barriers to obesity care in Spain, including stigma, mental health, funding/resources, education, and misconceptions. Recommendations to overcome these barriers included early prevention, patient engagement, shared decision-making, communication, and recognition of obesity as a chronic disease. Conclusion: This review reveals a consistent and multi-level gap between the documented burden of obesity in Spain and its identification, treatment, and prioritization within the healthcare system. Addressing this gap will require coordinated efforts across clinical documentation, therapeutic intervention, patient education, and health policy.