03 Sep 2013
The trend of increasing body mass index (BMI) may be slowing down in most English adults, according to research published by researchers from The University of Manchester online in the International Journal of Obesity this week.
Around two thirds of women and three quarters of men may be relatively resistant to further rises in BMI, the study suggests.
Professor Andrew Renehan, from Manchester Cancer Research Centre, a partnership between The University, The Christie NHS Foundation Trust and Cancer Research UK, and colleagues from The University of Manchester’s Faculty of Medical and Human Sciences and Faculty of Humanities, used a mixture modelling method to analyse BMI data collected from the Health Surveys for England between 1992 and 2010.
Mixture modelling can find clusters of people in a diverse population. This work found two main clusters: 164,166 adults were categorised as either ‘normal BMI’ or ‘high BMI’, and possible influencing factors such as smoking, education and income were taken into account.
Both men and women from the high-BMI group showed rising weight in early and middle adulthood, with falls in later life. However, in the normal-BMI group, the mean BMI of females steadily increased throughout early and middle adulthood, while the mean BMI of males increased the most in early adulthood.
Professor Renehan and co-authors suggest that this constant sub-population of normal-BMI individuals who seem to be resistant to further BMI increases may off-set the BMI increases experienced by the high-BMI individuals who are getting fatter.
Professor Renehan, Professor of Cancer Studies and Surgery at The University of Manchester and Consultant Colorectal Surgeon at The Christie NHS Foundation Trust, said: “The findings support the need for smarter targeting of policies to tackle the determinants of obesity.”
Professor Iain Buchan, Professor of Public Health Informatics at The University of Manchester, and Co-director of the national Farr Institute for Health Informatics Research, said: “This research shows the importance of health surveys and their detailed analysis – previous projections of rising obesity have made bold assumptions rather than listening to the data”… “Despite the slowing down in the rise of excess weight, there is no room for complacency as society still has to deal with the cumulative consequences of the obesity epidemic – affecting a minority of people more than others, but still everybody’s problem in finding a sustainable solution.”