Body composition and diet of Chinese, Malays and Indians in Sininfluence on cardiovascular risk factorsgapore: and their

Abstract

This thesis describes the studies on body composition and dietary intakes of the three major ethnic groups residing in Singapore, and how these are related to cardiovascular risk factors in these groups.Body composition : Body fat percentage was measured using a four-compartment model described by Baumgartner. When the relationship between body mass index (BMI) and body fat percentage was studied, it was discovered that Singaporeans have higher percentage of body fat compared to Caucasians with the same BMI and that the BMI cut-off value for obesity in Chinese and Malays is around 27 kg/m 2 , while that for Indians is around 26 kg/m 2 . At levels of BMI and waist-to-hip ratio which are much lower than the WHO recommended cut-off limits for obesity and abdominal fatness respectively, both the absolute and relative risks of developing cardiovascular risk factors are markedly elevated for all three ethnic groups. Both the excessive fat accumulation and increased risks at low levels of BMI signal a need to re-examine cut-off values for obesity among Chinese, Malays and Indians.Diet : Dietary intakes of energy, total fat, saturated fat, polyunsaturated fat, monounsaturated fat and cholesterol were measured using a food frequency questionnaire specially validated for this purpose. In addition, intakes of fruits, vegetables and grain-based foods were also measured using the same questionnaire. Singaporeans generally have a low intake of fruits, vegetables and whole grain products. The intake of total fat is just within the upper recommended limit while that for saturated fat is higher than the recommended level. On a group level, it is found that high intakes of fat, saturated fat and low intakes of polyunsaturated fat and vegetables affect serum cholesterol levels adversely. However, on an individual level, due to the rather homogenous intake patterns among the three groups, this cross sectional study was unable to demonstrate that dietary intakes could explain the differences in serum cholesterol levels among ethnic groups.In summary, the thesis shows that in the light of increased body fat percentage and cardiovascular risks at low BMI, there is a need to re-examine the WHO's cut-off values for the three major ethnic groups in Singapore. Longitudinal studies are also needed for better insight into the effect of dietary intakes and other lifestyle risk factors on cardiovascular risk factors and mortality.</p