Although the specific etiological mechanisms have not been fully delineated, it is well recognized that mental function can be adversely affected by poor dietary choices. As shown in Figure 28–1, the interrelationships among diet and physical activity, mental health, and physical health are critical determinants of health and quality of life among older adults. A problem in any one component can lead to deterioration in other components and in overall health. For example, as shown in Figure 28–2, excess kilocalorie intake may lead to obesity and related physical impairments that may in turn promote depression.