Obesity has been identified as the primary factor behind 86 per cent of long-term health condition combinations, according to the authors of a significant new paper examining the connection between weight and chronic illnesses. In what represents the largest study of its kind ever conducted, researchers have determined that excess weight serves as the "major driving force" between commonly occurring and potentially life-threatening conditions, including chronic kidney diseases, osteoarthritis, and diabetes.
Comprehensive Analysis of Health Condition Links
A dedicated research team from the University of Exeter undertook an extensive analysis of 71 different conditions that typically occur together, such as Type 2 diabetes paired with osteoarthritis, with the specific aim of establishing whether obesity functioned as a significant risk factor. The researchers utilised comprehensive genetic and healthcare data drawn from thousands of participants who had taken part in previous studies, revealing that obesity—defined as having a body mass index (BMI) exceeding 30—contributed to 61 out of the 71 condition combinations, equating to approximately 86 per cent.
Quantifiable Benefits of Weight Reduction
The study produced compelling evidence regarding the preventive power of weight loss. For every 1,000 individuals suffering from chronic kidney disease alongside osteoarthritis, lowering BMI by just 4.5 points could prevent approximately 17 people from developing both conditions simultaneously. Similarly, this same modest BMI reduction could prevent about 9 people per 1,000 from developing the dual burden of type 2 diabetes and osteoarthritis.
Furthermore, the research demonstrated that obesity accounted for all of the genetic overlap observed in ten specific pairs of conditions, strongly suggesting that excess weight represents the principal driver explaining why these illnesses frequently occur together. These critical pairings included chronic kidney disease and a group of lung conditions known as chronic obstructive pulmonary disease (COPD); gout and sleep apnoea; kidney disease combined with osteoarthritis; and type 2 diabetes.
Expert Insights and Clinical Implications
Professor Jack Bowden, a leading biomedical data scientist and the study's lead author, emphasised the importance of these findings: "We have long understood that certain diseases often occur together, and also that obesity increases the risk of numerous diseases. This large-scale study represents the first to utilise genetics to quantify the precise role of obesity in causing diseases to manifest within the same individuals."
Professor Bowden continued: "We discovered that for some disease pairings, obesity is indeed the major driving force. Our research provides substantially more detailed insight into the links between obesity and disease, which will assist clinicians in targeting specific, actionable advice to patients moving forward." The research team also successfully identified pairs of conditions where obesity does not serve as the primary cause and are currently investigating other potential underlying factors.
Strengthening Public Health Approaches
Experts assert that these findings, published in the respected journal Communications Medicine, significantly strengthen the argument for tackling obesity through coordinated public health programmes and could dramatically reduce the risk of individuals accumulating multiple health conditions. The team further emphasised that this research should reinforce the critical importance of weight management initiatives within the NHS framework, particularly given that obesity is already estimated to cost the country approximately £100 billion annually, including £19 billion in direct NHS expenditure.
However, the study acknowledges certain limitations. Primarily, the data analysed originated from individuals of predominantly northern European descent, and the research did not account for lifestyle factors that are widely recognised as contributors to obesity. Currently, at least nine million people across the UK live with two or more long-term conditions—a situation that could potentially be prevented through effective weight management strategies.
Broader Health Context and Future Priorities
Professor Jane Masoli, a consultant geriatrician and regional NIHR Ageing lead, added her perspective: "Understanding how to prevent diseases from accumulating represents a key national research and healthcare priority. This study further strengthens the compelling case for addressing obesity through comprehensive public health programmes, reinforcing the importance of lifelong obesity management within the NHS strategy on prevention."
Professor Masoli elaborated: "Our work clearly demonstrates that effective intervention could substantially reduce the risk of accumulating multiple health conditions, thereby supporting people to live longer, healthier lives." This research emerges alongside warnings from experts that as many as nine million individuals face heightened risks of heart attack, stroke, and kidney failure due to living with cardiovascular-kidney-metabolic syndrome—a condition linking heart disease, chronic kidney disease, type 2 diabetes, and obesity.
When these conditions occur together, they dramatically accelerate damage to the heart, blood vessels, and kidneys. Yet CKM syndrome currently lacks formal recognition within the NHS structure. Consequently, patients are typically treated for each illness separately—a fragmented approach that clinicians argue leaves individuals unaware of their true level of risk and delays potentially life-saving interventions. Current estimates suggest a further 40 million adults could develop this complex syndrome in the coming years, underscoring the urgent need for integrated healthcare strategies.
