Final answer:
The average energy intake needed to maintain weight can be estimated using the basal metabolic rate and Atwater system, factoring in individual characteristics and the energy content of foods.
Step-by-step explanation:
The method established to estimate the average energy intake needed to maintain weight is most closely associated with the concept of the basal metabolic rate (BMR), combined with an individual’s additional energy expenditure due to activities. To maintain weight, one must consume calories that match their total energy expenditure, which is the sum of their BMR and energy used during physical activity.
The BMR is a measure of the number of calories your body needs to perform basic functions at rest, like maintaining body temperature, breathing, and circulation. This figure varies depending on factors such as age, gender, weight, and muscle mass. Athletes, for example, may have a higher BMR due to a greater muscle mass.
To estimate the average energy needs, one might use the Atwater system, which determines the energy content of foods by multiplying the quantities of carbohydrate, proteins, and fats by the average calories per gram for each one. The total energy intake is then adjusted according to the individual’s activity level to estimate the energy needed to maintain weight.