Nutrition Science and Everyday Application - beta v 0.1

Overweight and Underweight—What are the
Risks?
As the previous section illustrated, energy balance is influenced by many factors. Whether
an individual is in positive or negative energy balance ultimately influences the overall trend
in whether that individual is normal weight, overweight, or underweight. While much of the
focus in society is placed on concerns with being overweight or obese, both ends of the
weight spectrum are associated with health risks, and being underweight can negatively
impact health just as being overweight can. In fact, research has shown a J-shaped
association between mortality risk and BMI, with greater risk for dying in underweight
and obese populations and the lowest risk occuring in the normal BMI range. 1
Figure 7.14. The relationship between body mass index and mortality forms a J-shaped curve,
demonstrating higher rates of death associated with underweight and overweight/obese, with
lowest rates of death associated with normal weight.
393