Final answer:
All listed options (a, b, and c) are correct as causes of malnutrition, which can occur due to eating too little, ingesting nutrients in improper amounts, or eating too much.
Step-by-step explanation:
Malnutrition is a state that results from eating a diet in which certain nutrients are either not enough or are too much such that the diet causes health problems. It not only refers to inadequacies but also to excesses in the diet. As such, all three options given contribute to malnutrition: a) Eating too little of the recommended foods can lead to undernutrition, b) Ingesting some nutrients in inappropriate amounts can cause deficiencies or toxicities, and c) Eating too much of the recommended foods can result in overnutrition.
Thus, good nutrition requires not only eating the right amounts but also maintaining a balanced intake of the essential nutrients. Knowledge about food and understanding the consequences of dietary choices are critical in preventing malnutrition.
Whether it is choosing a balanced meal for lunch, understanding the roles of various nutrients, or recognizing the signs of nutrient deficiencies, it all contributes to the mitigation and prevention of malnutrition.