Early emergence of ethnic differences in chronic disease risk: the contribution of diet and physical activity

British South Asians face increased risks of obesity, type 2 diabetes and coronary heart disease; British African-Caribbean adults face increased risks of obesity, type 2 diabetes and stroke in adult life. The reasons for these patterns are not fully understood. However, there is growing evidence that these ethnic differences in disease risk emerge early in life, offering opportunities for early prevention (particularly in these high risk ethnic groups) before the diseases are established. Diet and physical activity are both risk factors for obesity, type 2 diabetes and cardiovascular disease and could be important in explaining ?and preventing - these ethnic differences in disease risk. However, we know little about the extent of ethnic differences in diet and physical activity among British South Asians and African-Caribbeans, especially in children. We therefore propose to assess diet and physical activity patterns among 2000 British primary school children of South Asian, African-Caribbean and European origin during an ongoing health survey. The information which we will collect will allow us to examine the following questions:-
-How much do diet and exercise patterns vary between 9-10 year-old children children of different ethnic groups?
-How important are these differences in diet and exercise patterns in explaining emerging differences in risks of obesity, diabetes and cardiovascular disease between children from different ethnic groups?
-What are the factors (at individual, family, school and community levels) which affect the dietary and physical activity patterns of these children? Do these factors differ between ethnic groups?

The information collected will be used to inform strategies for early prevention of obesity, type 2 diabetes and cardiovascular disease, particularly in these high-risk ethnic groups.

British South Asian adults have increased risks of obesity, type 2 diabetes and coronary heart disease compared with White Europeans, while those of African-Caribbean origin have increased risks of obesity, type 2 diabetes and stroke. Recent studies suggest that these ethnic differences in disease risk are persisting in second/third generation immigrants and that they emerge in childhood. Dietary and physical activity patterns are important determinants of risks of obesity, type 2 diabetes and cardiovascular disease; ethnic differences in diet and physical activity could be important in the aetiology of ethnic differences in risks of these diseases and may offer scope for prevention. However, information on the extent to which diet and physical activity differs among British children from different ethnic groups is limited. In an ongoing survey of the cardiovascular health of 9-10 year old British children among different ethnic groups, we will carry out detailed assessments of dietary intake (using a 24 hour dietary recall and a 3-day prospective dietary diary) and make objective measurements of physical activity over a 7-day period using the validated Actigraph movement sensor. The information collected will allow us (a) to quantify ethnic differences in dietary intake and levels of physical activity; (b) to determine the relations of diet and physical activity to adiposity, insulin resistance, the metabolic syndrome and other cardiovascular risk markers among children of different ethnic groups; (c) to examine the extent to which ethnic differences in diet and physical activity explain emerging ethnic differences in these risk markers and (d) to study the potential determinants of diet and physical activity levels in an ethnically diverse population of children (including factors measured at individual, family, school and community levels). The results of the study will inform the development of strategies directed to early prevention of chronic disease in these high-risk ethnic groups.