Carrying some extra timber around your waist puts you at an increased risk of 13 different cancers which have been linked to obesity, with new research finding that waist size is as good an indicator of cancer risk as body mass index (BMI).
The research, published in the British Journal Of Cancer, found that men with a waist size of over 102cm (40in) for men (88cm/35in for women) resulted in an increased risk. Adding 11cm to the waistline raised the risk of obesity-related cancers by 13%. For bowel cancer in particular, adding just 8cm to the waistline increases the risk by 15%.
Being overweight is the second largest preventable cause of cancer after smoking. Excess body fat can alter the levels of sex hormones like testosterone and oestrogen in the body, cause inflammation, and increase levels of insulin – three factors that are all linked to a higher risk of cancer.
The study was undertaken by the International Agency for Research on Cancer, a branch of the WHO, and looked at data from 43,000 people tracked for an average of 12 years. More than 1,600 of them were diagnosed with an obesity-related cancer during the period.
BMI, waist circumference and waist-to-hip ratio were correlated with the risk of obesity-related cancers, with the study finding that all three measurements of body fat were good indicators.
Where waist measurement can prove most useful is in highlighting the amount of visceral fat a person is carrying. This type of fat wraps around the organs and is a greater danger to health than fat carried elsewhere on the body, and a larger waist size is a good indicator that a person is carrying high levels of visceral fat.
The BMI measurement uses a simple weight measurement and so does not differentiate between the amount fat or muscle on the body, and it also cannot identify where fat is carried.
However, the study shows that being in the overweight or obese bracket by any measurement is bad news, so it’s worth keeping tabs on weight by whatever method you prefer. Waist size has the advantage of being the easiest to find out – just wrap a tape measure around your waist at the belly button.