Final answer:
Balance is a key characteristic of a healthy diet, which entails consuming appropriate amounts of all nutrients. Other important aspects include moderation and variety, which contribute to a well-rounded, nutrient-rich diet.
Step-by-step explanation:
A key characteristic of a healthy diet is balance. This means consuming appropriate amounts of all nutrients without favoring one over another, which ensures that the body's needs are met for proper bodily functions, health, and reproductive capability. Additionally, two other prime characteristics of a healthy diet are moderation and variety. Moderation encourages not eating to the extremes and variety involves eating different foods from all the food groups to guarantee you get all the essential nutrients required for good health. A balanced diet also avoids excess intake of nutrients while providing sufficient amounts of each essential nutrient, fiber, and calories.