Which nutrient category must be supplied by the diet?

The category of nutrients that must be supplied by the diet is essential nutrients. These are substances that the body cannot synthesize on its own, or cannot produce in sufficient quantities to meet its needs, and therefore must be obtained from food. Essential nutrients include certain amino acids, fatty acids, vitamins, and minerals that play critical roles in various bodily functions such as metabolism, immune function, and overall health.

The other categories mentioned do not fit this definition. Non-essential nutrients can be produced by the body and do not need to be consumed through diet, while caloric nutrients refer to macronutrients like carbohydrates, proteins, and fats regardless of whether they are essential or non-essential. Micronutrients, while crucial for health, include both essential nutrients (which must be obtained through diet) and non-essential nutrients, thus not all micronutrients fit the criteria of being diet-supplied. Therefore, essential nutrients specifically highlight the need for dietary intake for proper physiological function.