Do neighbourhood environments contribute to ethnic differences in obesity, physical activity and diets?

Halting the rise in obesity is a policy priority as reflected in a range of government initiatives on diet and physical activity in schools and the community, and on legislation to promote a food classification system to make choosing healthy food easy. Ethnic differences in obesity are well known but the cause is poorly understood. This study seeks to understand if the context of where people live plays a role, whether it affects physical exercise and dietary patterns and their body size.
Ethnic minorities tend to live in poor urban areas and these areas might be less well served with facilities for physical activity or might be felt to too unsafe to take up physical exercise. Fast food outlets are known to be more common in deprived areas. Ethnic minorities living in (predominantly White) affluent areas may have better access healthy foods and take more exercise than those living in poor areas. These issues have relevance to policies that aim to help people from different backgrounds to engage in healthy lifestyles and to prevent obesity. For example, if both poor access to recreational facilities and high concentration of South Asians in areas were associated with low physical activity in South Asian women, it would be important to consider culturally appropriate ways of providing these facilities.
We will use national surveys that hold data about physical activity, diet, body size on individuals from ethnic minority groups. We will also use a range of data that describe the context of the areas people live in such as the size of ethnic minority populations living in an area, the poverty level of areas, the crime rates in areas, and the number of fast food outlets and gyms and how far these are from where people live. These data will allow us to examine the extent to which the obesity, physical activity and dietary patterns in ethnic minority groups are shaped by the places they live.

Background: Halting the rise in obesity is a policy priority as reflected in a range of government initiatives on diet and physical activity in schools and the community, and on legislation to promote a food classification system to make choosing healthy food easy. This study will enhance these initiatives by developing the evidence base about the extent to which ethnic minorities are exposed to obesogenic (obesity promoting) environments. In adulthood, Black Caribbean, Black African and Pakistani women are more likely to be obese than women in the general population. South Asians are more prone to abdominal adiposity. In adolescence, Black African origin girls are already more likely to be obese. In contrast to the US, there is very little research on the effect of neighbourhood environments on ethnic differences in health in the UK. Ethnic minority groups are spatially concentrated in relatively deprived urbanised areas and worry more about crime than their White peers. Physical characteristics of the neighbourhood such as the presence of grocery stores that sell healthy foods, safe parks, and recreational facilities, may promote healthy eating and exercise through increased availability and accessibility. Deprived areas may be less well served with these facilities. Perceptions of safety in neighbourhoods also influence the likelihood of taking physical activity.
Aim: The overall aim of this study is to examine whether ethnic differences in physical activity and dietary patterns, BMI and obesity status are related to exposures in the neighbourhoods they live in.
Method: The Health Surveys for England (HSE) (1999 and 2004) holds a range of data on individuals (e.g. including physical activity, diet, body size) from the major ethnic minority groups. Area measures of ethnic density, deprivation, food retail environment and physical activity opportunities will be obtained from a range of data sources (e.g. Neighbourhood Statistics, SportEngland). These ecologic data will be merged to the individual records on the HSE. The distribution of resources and the mean distance from to the nearest resource will be explored in relation to deprivation and ethnic density. Different measures of ethnic density will be used to reflect concentration and clustering in particular areas. Multilevel models will be used to examine how individual characteristics (compositional factors) and area-level variables (contextual factors) relate to ethnic differences in outcomes.