Final answer:
Inadequate nutrient intakes can lead to impaired immune function, with protein deficiencies having severe effects on various immune system components. Malnutrition affects energy balance, crucial for supporting the immune system's capacity to respond to infections.
Step-by-step explanation:
Intakes of nutrients that are either too high or too low could impair immune function. The immune system requires a balance in nutrient intake to function properly. Malnutrition, particularly inadequate protein intake, can lead to various forms of immunodeficiency by impairing complement system activity, phagocyte function, and the production of antibodies and cytokines needed for an effective immune response. Energy balance and nutritional status are crucial for supporting the immune system. Famine and malnutrition, common in developing countries, significantly affect this energy balance and thus the immune capacity. This can be traced back through history, where populations suffering from famine exhibited higher mortality rates during disease outbreaks. The fetus's development can also be influenced by nutritional status during pregnancy, possibly leading to long-term immune system impacts. Additionally, lifestyle factors such as obesity, alcoholism, or other drug abuses can compromise the immune system's function.