Which process primarily contributes to energy expenditure during work-related activities?

Non-exercise activity thermogenesis (NEAT) significantly contributes to energy expenditure during work-related activities because it encompasses all the calories burned through movements that are not classified as deliberate exercise. This includes everyday tasks such as walking to your office, standing up, fidgeting, and even activities like typing or cleaning. Since a large portion of the day may be spent engaged in these types of activities, NEAT can represent a substantial part of total daily energy expenditure.

While the thermic effect of food (TEF) relates to the energy required for digestion and metabolism of food, it plays a smaller role in overall daily energy expenditure compared to NEAT. Basal metabolic rate (BMR) accounts for the calories burned at rest to maintain vital physiological functions, while aerobic exercise contributes to energy expenditure during specific periods of physical activity, typically requiring planned effort and time. In contrast, NEAT captures the more continuous energy expenditure that comes from simply engaging in daily activities, making it particularly relevant to the context of work-related energy expenditure.