Final answer:
Malnutrition is the condition in which the body's essential need for nutrients is not met by nutrient intake. It can be caused by either undernutrition or overnutrition, both of which have negative effects on overall health.
Step-by-step explanation:
Malnutrition is the condition in which the body's essential need for nutrients is not met by nutrient intake. It can be caused by either undernutrition, which is a lack of nutrients and insufficient energy supply, or overnutrition, which is excessive nutrient and energy intake. Both undernutrition and overnutrition can have negative effects on overall health. For example, inadequate intake of certain vitamins can lead to specific health problems, while excessive intake of certain nutrients can be toxic. Malnutrition can also result from unbalanced nutrition, where the diet contains too much or not enough of specific nutrients other than energy.