nutrition
This term describes the biological science of how the body utilizes food, carrying a clinical and health-oriented tone. It focuses on the chemical components of food rather than the act of eating for pleasure or satiety. In a professional context, it often relates to dietary guidelines, medical prescriptions, or scientific research. While "diet" refers to what a person actually eats, "nutrition" refers to the quality and effect of those nutrients on the body. A person can have a diet consisting of many calories but still suffer from poor nutrition if the food lacks essential vitamins and minerals.
Uncountable when referring to the general science or process of nourishment. Countable when referring to specific types or quality levels of nutrients, such as comparing the nutrition of different food groups.