Bayes work on obesity gets new lease of life

Groundbreaking research can have a long half-life – as two actuarial science professors are finding with their paper on the best clinical measure for obesity.

A report supported by more than 50 ‘global experts’ published in The Lancet Diabetes & Endocrinology last week emphasised the virtues of the Waist to Height Ratio (WHtR) for assessing obesity. The report said it was a more nuanced indicator for individuals than the long-established Body Mass Index (BMI).

That principle was investigated by a team at Bayes Business School, led by professors Ben Rickayzen and Les Mayhew, in 2014.

They showed that WHtR is a better predictor of mortality risk than BMI and, for the first time, they were able to quantify the years of life lost from being obese based on the WHtR measure. They are both academics at Bayes'  Faculty of Actuarial Science and Insurance which is marking its 50th anniversary this academic year.

Two years later, their colleague Dr Margaret Ashwell, Senior Visiting Fellow at  Bayes Business School and her co-author Sigrid Gibson published research suggesting that WHtR may be a simpler and more predictive indicator of the ‘early heath risks’ associated with obesity.

Based on their research, Professors Rickayzen and Mayhew urged policymakers to adopt the measurement over BMI in primary public health screenings. Subsequently, UK health advisory and regulatory body NICE (the National Institute for Health and Care Excellence) has incorporated WHtR into its obesity guidelines.

Welcoming the latest report, Professor Mayhew said: “We have been urging policymakers for a decade now to recognise the value of the WHtR to clinicians, their patients and the broader public. I hope this gives fresh impetus to its adoption and that clinicians and public health services encourage more people to see it as a tool for assessing their own health.”

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Last autumn the research pair’s work was quoted in the upmarket French women’s lifestyle bible Marie France.

The magazine reported: “The study, conducted over more than 20 years, analyzed the mortality of non-smoking women and men to understand what factors could predict their life expectancy. The researchers found that waist circumference, more than other indicators such as BMI, made it possible to better estimate the risk of mortality. Specifically, they found that if your waist circumference exceeds half your height, this may indicate an increased health risk.”