What is the term for the energy required to maintain life-sustaining activities while at rest?

The term that refers to the energy required to maintain life-sustaining activities while at rest is the basal metabolic rate (BMR). BMR represents the number of calories your body needs to perform essential functions such as breathing, circulation, cell production, and nutrient processing when the body is at rest and in a post-absorptive state (not actively digesting food). It reflects the minimum energy expenditure necessary for survival and is influenced by factors such as age, sex, body composition, and hormonal levels.

Understanding BMR is crucial for nutrition and health, as it forms the basis for calculating total daily energy expenditure (TDEE), which includes energy expended through physical activity and thermogenesis after eating. This helps in planning dietary needs and weight management goals. The other terms listed in the options refer to different concepts related to nutrition and do not pertain to energy expenditure while at rest.