Borderline obesity has been linked to a 30% greater likelihood of developing bowel cancer compared to people of a normal weight, according to a scientist working in the field of study.
Those with a body mass index (BMI) of 30 are a third more likely to be diagnosed with bowel cancer than someone nearer the lower end of the healthy weight range with a BMI of around 20, Dr Rachel Thompson from the World Cancer Research Fund (WCRF) said.
Dr Thompson advised people try to maintain a BMI of near 20 as research shows body fat is a cause of six types of cancer, including bowel cancer and post-menopausal breast cancer.
She added: "The evidence that being overweight increases your risk of cancer is stronger now than ever before.
"In fact, scientists now say that, after not smoking, maintaining a healthy weight is the most important thing you can do for cancer prevention.
"These figures show that people who are a healthy weight are significantly less likely to develop bowel cancer than those who are obese.
Excess weight is also linked to other conditions, including heart disease and type 2 diabetes.