The global obesity epidemic, attributed to sedentary lifestyles, unhealthy diets, genetics and environmental factors, has led to over 1.9 billion adults being classified as overweight and 650 million living with obesity. Despite advancements in early detection and treatment, lung cancer prognosis remains poor due to late diagnoses and limited therapies. The obesity paradox challenges conventional thinking by suggesting that individuals with obesity and certain diseases, including cancer, may have an improved prognosis compared with their counterparts of a normal weight. This observation has prompted investigations to understand protective mechanisms, including potentially favorable adipokine secretion and metabolic reserves that contribute to tolerating cancer treatments. However, understanding the association between obesity and lung cancer is complex. While smoking is the primary risk factor of lung cancer, obesity may independently impact lung cancer risk, particularly in non-smokers. Adipose tissue dysfunction, including low-grade chronic inflammation, and hormonal changes contribute to lung cancer development and progression. Obesity-related factors may also influence treatment responses and survival outcomes in patients with lung cancer. Τhe impact of obesity on treatment modalities such as chemotherapy, radiotherapy and surgery is still under investigation. Challenges in managing patients with obesity and cancer include increased surgical complexity, higher rates of postoperative complications and limited treatment options due to comorbidities. Targeted interventions aimed at reducing obesity prevalence and promoting healthy lifestyles are crucial for lung cancer prevention. The impact of obesity on lung cancer is multifaceted and requires further research to elucidate the underlying mechanisms and develop personalized interventions for prevention and treatment.