Obesity: We know a lot, but are still not successful in prevention and weight loss therapy
Rising Awareness and Unmet Goals
In 2025, World Obesity Day continues to spotlight the alarming rise in global obesity rates. This growing epidemic poses a significant threat to chronic disease prevention and overall health across the lifespan. It’s crucial to implement actions and interventions to curb and address this problem effectively.
Staggering Statistics and Underlying Causes
In 2020, approximately 2.6 billion people worldwide were either overweight or obese (BMI ≥25kg/m²). Projections suggest that this number could exceed 4 billion by 2035. The complexity of obesity stems from a blend of genetic, socio-economic, and cultural influences. Adopting lifestyle changes that reduce energy intake and boost energy expenditure is essential in combating this trend. Moreover, environmental factors, such as the use of chemicals in agriculture (e.g., pesticides) and food preservation and packaging (e.g., plasticizers), are increasingly recognized as contributors.
Health Implications and Individual Variability
Obesity is closely linked to metabolic comorbidities, including type 2 diabetes, metabolic dysfunction-associated fatty liver disease, cardiovascular diseases, and certain cancers. Additionally, lipid metabolism abnormalities are prevalent among obese individuals. However, the risk of developing cardiometabolic diseases isn’t solely dependent on fat mass. Some individuals remain metabolically healthy despite being obese, while others with normal weight or low subcutaneous fat mass may still develop obesity-related diseases.
Heterogeneity of Obesity and Advances in Research
Recent research highlights that obesity is a heterogeneous condition, with a focus on metabolically healthy obesity. This state describes individuals with obesity who do not have immediate metabolic disorders but may develop them if obesity persists. Advances in genomics, metabolomics, and precision medicine offer hope in unraveling the complexities of obesity.
Limitations of BMI and Importance of Fat Distribution
While BMI is commonly used to assess comorbidity risk, it has limitations due to inter-individual differences related to sex, age, and other factors. BMI measures total body fat but not its distribution, which is crucial since metabolic risk is significantly influenced by fat distribution, particularly visceral adipose tissue.
Role of Visceral Adipose Tissue and Quantification
Research indicates that genetic and epigenetic alterations, immune system changes, gut microbiome dysbiosis, and adipokine dysregulation mediate the pathogenic link between visceral adipose tissue and comorbidities. Quantifying visceral adipose tissue is vital for assessing obesity-related complications and providing timely targeted treatments. Anthropometric indicators like the visceral adiposity index (VAI), waist circumference, and lipid accumulation product are useful in this context.
Lifestyle Changes and Individualized Treatment
Lifestyle changes should be the cornerstone of obesity treatment. A high-quality, hypocaloric diet combined with at least 150 minutes of moderate physical activity per week is recommended for weight loss. Personalized lifestyle programs, considering the patient’s motivation, goals, eating habits, preferences, complications, and previous attempts, are essential for long-term success. If behavioural interventions fall short, obesity pharmacotherapy, coupled with lifestyle modifications, may be considered.
Population-Level Interventions and Long-Term Challenges
At the population level, the primary goal is to halt the rise in obesity prevalence and prevent the accumulation of excess fat mass. A key strategy is preventing overweight and obesity during childhood and adolescence, laying the foundation for a healthy adult weight.
However, social and environmental challenges, lack of physical activity, and the abundance of affordable, energy-rich foods hinder efforts to control the global obesity epidemic. Sustainable weight loss and its long-term maintenance are paramount in combating the disease effectively.
Future Directions and Tailored Interventions
Despite various strategies, long-term success in preventing and treating obesity remains elusive. Lifestyle and behavioural interventions have limited efficacy due to complex hormonal, metabolic, and neurochemical adaptations that promote weight regain. Tailored interventions, based on refined pathophysiological phenotyping and obesity subtypes, could address associated risks and optimize therapeutic outcomes.
