MedicalResearch.com Interview with:
Dr. Mark A Green PhD
Department of Geography & Planning
University of Liverpool
Medical Research: What is the background for this study? What are the main findings?
Dr. Green: Previous research on trends in body mass index (BMI) have focused on changes in the middle value (average BMI). We extended this investigation by exploring trends both in the middle (using the median – the mid-point of BMI values), the 5th centile (the BMI value at which bottom 5% of the population with the lowest BMIs fall below) and the 95th centile (the BMI value at which the top 5% of the population with the highest BMIs fall above) to examine how trends have changed both in the middle, and at the top and bottom of the distribution. We found that median BMI increased in England in the 1990s, before beginning to slow its rate of change. This is contrary to the 95th centile which has continued to increase at a higher rate throughout the period, with little change in the 5th centile.
Medical Research: What should clinicians and patients take away from your report?
Dr. Green: Our results suggest that the slowing down of increases in median BMI hailed by some public health officials may not be quite the success it first appeared. As the top end of values in terms of BMI continues to grow, this may place considerable future burden on health services since it is at these values of BMI where the risk of poor health and numerous health conditions is greatest. Our results were consistent for both males and females, and by socio-economic status.
Medical Research: What recommendations do you have for future research as a result of this study?
Dr. Green: We do not know what is causing these trends (especially at the upper end of values), other than it being independent of gender and socio-economic factors. It is key therefore for future research to understand why we are seeing these trends to be able to design effective strategies to tackle it.
Dr. Mark A Green PhD (2016). Top End of BMI Range in Population Weight Continues to Rise