Obesity is a key factor behind rising cancer rates among younger adults in England, according to a new study. Researchers from the Institute of Cancer Research and Imperial College London analysed data from 2001 to 2019 and found that 11 types of cancer, including bowel and ovarian cancer, are increasing in people aged 20 to 49.
Obesity was the only known behavioural risk factor that increased in younger adults over this period, while smoking, alcohol consumption, red meat intake and physical inactivity remained stable or declined. Excess weight was associated with 10 of the 11 cancers identified, including thyroid, kidney and pancreatic cancer, with oral cancer being the exception.
The researchers estimated that maintaining a healthy weight could prevent about 20% of bowel cancers, 35% of endometrial cancers and 27% of kidney cancers. However, they noted that obesity does not fully explain the overall rise, suggesting unknown causes may also be at play.
Professor Montserrat García-Closas, co-director of the Cancer Epidemiology and Prevention Research Unit at the Institute of Cancer Research, said: “Excess weight is an important contributor, although it cannot fully account for the scale of the rise in bowel and other cancers. This tells us that multiple factors – including early-life exposures – may be acting together.” She called for stronger public health policies to tackle obesity, particularly in children and young people.
The study coincides with recent figures showing a record high in cancer diagnoses in the UK, with more than 403,000 people diagnosed each year. Michelle Mitchell, chief executive of Cancer Research UK, emphasised the need for more research and urged the government to prioritise cancer prevention through measures such as restricting junk food advertising and making nutritious food more accessible.
