This thesis is concerned with the use of anthropometric measurements and indices as tools to assess current adult nutritional status The practical characteristics, distribution and determinants of the anthropometric variables and also their relationships to morbidity and mortality were examined in a rural population in Sarawak. East Malaysia. The study made use of baseline anthropometric data obtained on 1047 adults in 1990. 94% of the survivors since 1990 were re-measured and re-interviewed in 1996. Verbal autopsies were applied to the closest relatives of the non-survivors since 1990.The body mass index (kg/m2) and mid-upper arm circumference better fulfilled the characteristics required for an ideal index of nutritional status in adults than any other anthropometric measurements or indices. Both the body mass index and mid-upper arm circumference were highly correlated with body energy stores and were relatively independent of height and shape. Negative associations of the body mass index and mid-upper arm circumference with mortality were observed when overweight (>=25kg/m2) individuals were excluded from the analyses. Age altered the strength of these associations Low mid-upper arm circumference and body mass index were associated with increased risks of self-reporting episodes of fever and epigastric or respiratory problems not associated with hypertension in a cross-sectional analysis of the non-obese (<=30kg/m2) population Amongst the non-obese section of the population who reported being healthy at the baseline, low mid-upper arm circumference was also associated with increased risks of self-reporting subsequent episodes of fever and epigastric or respiratory problems not associated with hypertension. Logistic regression found that the body mass index cut-off point of 18 5kg/nr was associated with increased risks of mortality when overweight individuals were excluded and early mortality was discounted. Amongst the non-obese section of the population who reported being healthy at the baseline, the body mass index cut-off point of 18.5 kg/m2 was associated with increased risks of self-reporting subsequent episodes of fever and epigastric or respiratory problems not associated with hypertension. Thus this study provides support for the hypothesis that the body mass index may be useful in the diagnosis of chronic energy deficiency However, the results suggest that a scheme which assesses current nutritional status in adults using anthropometric indices should consider employing distinct cut-offs for older adults.