Final answer:
The largest contributor to total energy expenditure for most individuals is basal energy expenditure or basal metabolic rate, accounting for about 75% of daily calorie consumption.
Step-by-step explanation:
The largest component contributing to total energy expenditure for most individuals is the basal energy expenditure (BEE), or basal metabolic rate (BMR). About 75% of the calories used in a day are attributed to BMR, which sustains the basic functions of various systems in the body, primarily the liver and spleen, followed by the brain. This energy homeostasis varies with factors such as age, gender, total body weight, and muscle mass – the more muscle mass one has, the higher the BMR, as evidenced by athletes who often have a greater BMR than non-athletes.