Estimated Energy Requirements – Human Nutrition

Mar 29, 2021

Energy is the essential component required by the body to undergo the metabolic process, to perform the physiological activities, and for the growth and synthesis of new body muscles. Energy is acquired through the procedure called oxidation.


The food components which are absolutely the core of obtaining energy are proteins, fats, and carbohydrates. The energy required for performing multiple metabolic activities is called BMR (stands for basal metabolic rate).

Relationship of growth and energy

Energy is also consumed to turn food into nutrients resulting in additional heat output and oxygen utilization frequently defined as 'dietary-induced thermogenesis,' 'thermal feeding effect' and 'unique food dynamic action'. The metabolic reaction to food boosts the BMR in people consuming a mixed diet by around 10 percent in one day.

                     Relationship of growth and energy

Growth is the ultimate process of tissue synthesis which needs energy. According to the WHO report of 2004, the growth uses around 35 percent of total energy needs in the first three months of life. It drops to 5% in the 12th month, to less than 2% in the 2nd year of development, 1–2% before middle adolescence and zero by 20th year of life.

Concept of Estimated Energy Requirement (EER)

The concept of EER has first established to raise public awareness. The need for awareness was felt due to prevalent health concerns because of obesity in North America. The set of equations are factors that are considered while calculating the EER or a person. The EER of a person accounts for the Physical activity level that is based on age, height, weight, and sex.


However, we must distinguish between the PAL and PA. PA is the physical activity coefficient. This coefficient tells the estimated energy level based on physical activity. PA and PAL levels are used in the equations.


The formulas used to measure the EER consider factors influencing the daily energy expenditure of a person, account for changes in physical activity-based energy consumption, and measure the impact of the physical activity levels on total energy expenditure (TEE).


Another aspect is the thermic effect of food (TEF) and thermoregulation. It contributes towards digestive and neutral processes related to eating etc. secondly it has a lesser impact on the total energy expenditure. The thermic effect of food enhances energy metabolism also it takes the energy of around 8-10% of how much a normal person spends energy on average. On the other hand, any kind of physical activity has a very less tendency of affecting the thermal effect of food.


Calculation of energy spend during physical activity is a tricky task as it is a variable component of the total energy expenditure. Though variable but equally important factor for maintaining the balance. Although it is difficult to gauge because varies from person to person but normally 20-30% of the energy spent is due to physical activity.

                       Concept of Estimated Energy Requirement

The measurement of physical activity is important because EER also takes it into the account. In estimated energy requirement (EER) the physical activity is taken as PA. the variability factor is taken into consideration through the formula given below. The coefficients can be seen that show the effect of strength and length od quality and quantity of the physical activities performed.


The oxygen factor that is consumed after post-exercise, is measured around 15%. This also accounts for the fact that energy expenditures slightly increased after the time in which physical activity has been completed.

Adult male EER = 662 - [9.53 * age (y)] + PA * [15.91 * wt (kg) + 5.39 * ht (m)]


The equation above shows the different factors explained below:

Physical activity (PA)

Year (y)

Weight (wt)

Height (ht)


As far as the number concerned which are shown in the equations are the calculations of a group of people having the same sex, age, and similar size of the body. The people in the group considered to have the same level of physical activity. To calculate their estimated energy levels, these formulas were carefully designed and then applied to the individuals having the same type of characteristics.


Therefore, in simpler words, the EER as the name shows is the approximation of the characteristics comprised by an individual. The values of estimated energy level no doubts vary from person to person such as an infant would have a different value of EER than an adult.


Similarly, a pregnant or lactating woman would have a different value than an overweight and obese person. Also, ponder to this point that measurement of estimated energy requirement is based upon the fact of weight maintenance and no on weight loss or weight gain.

Online calculators for checking the estimated energy level

Calculating the total energy expenditure can be boring if done manually. However, with so much advancement in technology, this task has also been made easier. Some online calculators can be sued, there is no need to download or install the application. The programs can be accessed online and the simple click can be used to measure the estimated energy requirement.


These web-based calculators save a lot of time that you spend doing the calculations. One such web-based calculator like has made the measurement of EER quite easy. All you must do is is to put in your gender, age, height, and weight. The rest of the task will be handled by this calculator. Then fill in the physical activity box. All these fields are mandatory to complete to get the value of EER. After hitting the ‘’calculate’’ button, you would get the value of EER in units of calories per day.


It is extremely important to calculate the estimated energy requirement whatever the method you opt to calculate it. For example, it shows what type of physical activities should a person select based on his EER score. Let us say a specific type of activity is influencing the score in negative then that activity should be dropped out. EER also tells what the minimum energy requirement of the person is.


If the energy level is below that certain point then a person normally feels weakness. Therefore, the estimated energy requirement also helps in selecting a balanced diet.