Acknowledging and treating childhood obesity as a chronic disease
The World Health Organisation (WHO) first recognised obesity as a disease in 1948 through the International Classification of Diseases (ICD). However, it took several decades for the severity of this public health issue to gain widespread attention. While concerns over obesity emerged in the United States and the United Kingdom 35 years ago , the issue was largely overlooked in other parts of the world. Despite emerging evidence and data from the WHO in the 1980s, the medical profession largely neglected the significance of the impact of obesity.
In 1995, the WHO discovered that overweight individuals outnumbered underweight individuals in many developing countries.
Yet, it wasn't until 1997, with the first special obesity consultation and subsequent studies on the disease burden in the new millennium, that the critical role of obesity in rising global medical costs became clear.
Governments now recognise the rapid industrialisation fuelling this epidemic, but both they and WHO remain uncertain about how to effectively encourage regular physical activity and shift the food system towards prioritising low-energy, nutrient-rich foods.
Early intervention in obesity can prevent the disease from leading to severe psychosocial and somatic complications across multiple organs, which could impede normal growth and development. Recognising childhood obesity as a disease is crucial for fostering the development of new treatments and health policies aimed at preventing and managing obesity.
The term "disease," as defined by Merriam-Webster, refers to a condition that impairs the normal functioning of an organ or its parts, typically manifested by signs and symptoms. However, when it comes to obesity, there is considerable debate about whether it should be classified as a disease. Declaring obesity as a disease has several implications, including increased access to healthcare professionals, potential for disability privileges in severe cases, and greater research funding to understand and treat the condition. It may also lead to reduced stigma and discrimination. One of the key advantages of recognising obesity as a disease is the shift away from a "blame and lack of willpower" culture, placing the responsibility of care on healthcare professionals. The debate surrounding the classification of obesity as a disease centres on the diagnostic criteria. Currently, the Body Mass Index (BMI) is the most widely used tool for diagnosis, yet it is a crude measurement that doesn't always reflect the presence of disease. For instance, individuals with a high BMI but low body fat percentage may be incorrectly diagnosed as obese, despite not having the disease. While many healthcare professionals and organisations agree that obesity should be classified as a disease, some countries have already adopted this view, the diagnostic criteria remain a contentious issue.
The World Health Organisation (WHO) defines obesity as having a BMI greater than 30 kg/m², but this definition, based solely on BMI, fails to capture the full complexity of the condition. In contrast, the Obesity Medicine Association (OMA) offers a more comprehensive view, describing obesity as a "chronic, progressive, relapsing, multifactorial, neurobehavioural disease" resulting from an increase in body fat. According to this definition, excess body fat causes dysfunction in adipose tissue, leading to negative effects on metabolism (adiposopathy), biomechanics (fat mass disease), and psychosocial well-being.
Recognising obesity as a disease paves the way for a more holistic and scientific approach to treatment and its public health impact. It calls for healthcare providers to move away from a biased "lack of willpower" approach and instead adopt a framework focused on chronic disease management. This includes appropriate staging, diagnostic tools, treatment options, complication management, and outcome measures.
Obesity arises from an imbalance between energy intake and expenditure, resulting in excess calories being stored as fat. However, this simplistic view of "eat less, exercise more" fails to account for the complex systems that regulate energy balance, such as the communication between the brain, gut, and peripheral tissues. The brain plays a central role in regulating body weight through neural pathways that interact with peripheral tissues. The gastrointestinal (GI) system and adipose tissue are key players in weight regulation. The GI tract senses meal volume and controls gastric emptying, while hormones released by the small intestine influence appetite. Adipose tissue secretes hormones that regulate food intake and energy expenditure. Additionally, genetic and epigenetic factors contribute to obesity, with certain genes and environmental factors influencing traits like appetite and metabolism. Obesity has profound effects on physical, mental, and social well-being, increasing the risk of conditions such as osteoarthritis, sleep apnoea, type 2 diabetes, liver disease, and cancer. Moreover, weight stigma and discrimination lead to negative psychological and societal consequences for individuals with obesity. Recognising obesity as a disease is essential for creating more effective treatment strategies and reducing the burden of these associated health impacts.
