On 4th February 2014, Public Health England (PHE) released new local authority level data on excess weight in adults aged 16 and over. The measure reports the percentage of adults classified as overweight or obese and supports a new indicator in the Public Health Outcomes Framework. Data is available for all local authorities in England. To view a spreadsheet containing the excess weight data only, visit the PHE obesity website.
The data is based on adjusted, self-reported height and weight measurements collected through the Active People Survey (APS) by Sport England since January 2012. The APS results are weighted to be representative of the adult population at local authority level in terms of age by sex, ethnicity, working status by sex, household size and socioeconomic classification (NS-SEC). PHE has undertaken extensive analysis of the data to ensure it provides a high quality and robust indicator of the prevalence of excess weight among the adult population. This is reported as indicator 2.12 Percentage of adults classified as overweight or obese, in the Public Health Outcomes Framework. The data tool allows you to view comparisons with other areas and the national average.
Notes on the methodology and definition of the indicator:
The numerator for this measure is the number of adults (aged 16 years and over) with a body mass index (BMI) classified as overweight (including obese), calculated from the adjusted height and weight variables. Data are from APS6 quarters 2-4 and APS7 quarter 1 (mid-Jan 2012 to mid-Jan 2013). Adults are defined as overweight (including obese) if their BMI is greater than or equal to 25kg/m. The denominator is the number of adults with valid height and weight recorded for the same survey period.
Questions on self-reported height and weight were added to the Active People Survey (APS) for the first time from January 2012 to provide data for monitoring excess weight in adults at local authority level for the Public Health Outcomes Framework (PHOF). It is known that adults tend to underestimate their weight and overestimate their height when providing self-reported measurements and the amount to which this occurs can differ between population groups. Therefore prevalence of excess weight (overweight including obese) calculated from self-reported data is likely to produce lower estimates than prevalence calculated from measured data.
To assess the accuracy of the self-reported height and weight, data from the APS were compared with measured height and weight data from the Health Survey for England (HSE) 2006-2010. Similar analysis was performed using the 2011 HSE data where both self-report and measured height and weight were collected from the same individuals. These analyses found that the differences between self-reported and measured height and weight vary in a systematic way, primarily as a function of age and sex. This systematic variation can be described by formulas, which have been used to adjust self-reported height and weight measurements at an individual level to estimate the likely actual height and weight of those individuals.
The self-reported height and weight values for individuals have been multiplied by the appropriate adjustment factor for that age and sex to obtain an estimate of the true height and weight of that individual. Whilst these will not be precise at an individual level, at a population level they act to bring the APS data much more closely into line with the actual measures, such as those described by the HSE.
The counts were weighted to be representative of the whole population at each level of geography. The weighted and unweighted denominators will be published on the PHE Obesity Knowledge and Intelligence website http://www.noo.org.uk/visualisation/.
