ABSTRACT
One of the most important measurements in nutritional assessment is body weight. Weight is an important variable in equations that predict energy expenditure and indices of body composition. Measurement of a person’s weight in conjunction with his/her stature or height do provide some value in predicting health and risk of death. There is good evidence that overweight individuals tend to die sooner than averageweight individuals, especially those who are overweight at a younger age (Must et al. 1999; National Task Force on the Prevention and Treatment of Obesity 2000). A positive relationship has been demonstrated between body mass index (BMI – a weightheight index discussed later in this chapter) and mortality rate for cancer, heart disease, and diabetes mellitus, when BMI is above 25 kg m2. Some researchers believe that the lowest mortality rates in the United States and many other Western nations are associated with body weights somewhat below the average weight of the population under consideration (National Task Force on the Prevention and Treatment of Obesity 2000). On the other hand, one should be cautioned against encouraging weight loss when it is not needed. A body weight that is too low is unhealthy and increases the risk of death. This can be seen in people suffering starvation or anorexia nervosa. Existing evidence suggests that as BMI falls below about 20, the risk of death increases.
