Final answer:
Essential nutrients are substances that must be obtained from food because the body cannot synthesize them in adequate amounts. These include certain amino acids, fatty acids, vitamins, minerals, water, and fiber. Macronutrients and micronutrients are both categories that contain essential nutrients.
Step-by-step explanation:
Nutrients that a person must obtain from food because the body cannot make them in sufficient quantity to meet physiological needs are known as essential nutrients. These nutrients are critical for maintaining health and supporting the body's various functions. Within the broad range of nutrients, there are macronutrients, including carbohydrates, proteins, lipids, and water, that the body requires in larger amounts. Alongside these, we have vitamins and minerals, which are classified as micronutrients and are needed in smaller quantities but are equally essential to body functions.
The inability of the body to synthesize essential nutrients in an adequate amount necessitates obtaining them through the diet. This includes certain amino acids (from proteins), fatty acids (from lipids), vitamins, minerals, water, and fiber. The human body can produce nonessential nutrients on its own, so it's not necessary to get them from food, though they are also commonly consumed as part of a regular diet.