Energy expenditure refers to the amount of energy that an individual or organism uses to carry out various bodily functions, such as breathing, circulating blood, and physical activity. This is typically measured in terms of calories burned or kilocalories expended per day. Researchers in the field of energy expenditure study how different factors, such as age, gender, body composition, and physical activity level, influence the amount of energy that a person expends. They also investigate how changes in energy expenditure can impact overall health and weight management. By understanding energy expenditure, researchers can develop strategies to help individuals maintain a healthy weight, improve fitness levels, and prevent chronic diseases such as obesity and diabetes. This research area plays a crucial role in promoting overall health and wellbeing.