What is your daily calorie requirement?

 What is your daily calorie requirement?

In this article, the main focus is on the daily calorie requirement, factors affecting the calorie requirement of an individual, means of calorie expenditure, and calculation of daily calorie requirement.

What is your daily calorie requirement?

The daily calorie/ energy requirement is crucial for maintaining a healthy life. The daily calorie intake should be sufficient to fulfill the daily calorie requirement. 

If the daily calorie intake is less than the daily calorie requirement, your body tends to be in a negative energy balance over time. This can lead to weight loss and severe conditions can cause drainage of muscle mass.

Daily calorie intake < Daily calorie requirement → NEGATIVE ENERGY BALANCE

If the daily calorie intake is greater than the daily calorie requirement, your body may get into a positive energy balance in the long run which leads to gaining weight. Sometimes specific physiological states demand more calories than the regular requirement, like pregnancy, lactating mothers, and adolescents 

Daily calorie intake > Daily calorie requirement → POSITIVE ENERGY BALANCE

Factors affecting the calorie requirement of an individual

Age

Gender

Weight and height

Physical activity

Means of calorie expenditure

• Resting Metabolic Activities/ Basal Metabolic Activities (60-70%)

Even when the body is at complete rest, energy is required for various internal processes.

Example - Heartbeat, blood circulation

     Respiration - inhalation-exhalation

     Liver and kidney function

Resting Metabolic Rate (RMR) is referred to as the energy required per unit time to maintain a subject at complete rest.

RMR is referred to as the energy required for an individual,

• lying down

• awake

• at complete rest (physically and mentally)

• wearing light clothes

• post-absorptive state (12 - 15 hours after having meals)

• at a comfortable room temperature

RMR is expressed as kCal/min commonly.

The amount of energy required during sleeping is approximately equal to RMR.

• Physical Activities (15-30%)

The calories required for physical activities vary from individual to individual.

• Thermogenic Effect/ Specific Dynamic Action (10%)

This is the energy required for absorptive actions like (active transport, osmotic balance) after consuming food.

Calculation of daily calorie requirement

Method 1

This can be calculated by multiplying the RMR per day with a factor called ‘Activity Factor’.

Daily calorie/energy requirement = RMR x Activity Factor

Methods to calculate RMR

• General formula

Male =           1kCal     x   24 hours   x   body weight

                      kg body weight x hour

         =     24 x body weight     kCal

                            day

Female =      0.9kCal    x   24 hours   x   body weight

                    kg body weight x hour

              =     21.6 x body weight     kCal

                                      day

• Mifflin St Jeor Equation (2005)

Male = (10 x weight) + (6.25 x height) - (5 x age) + 5

Women = (10 x weight) + (6.25 x height) - (5 x age) - 161

(Weight in kg, height in cm, age in years)

• FAO/WHO/UNU 1985 procedures 

Age	Male	Female
18-30	15.3 x body weight + 679	14.7 x body weight + 496
30 - 60	11.6 x body weight + 879	8.7 x body weight + 829

(weight in kg)

• Harris-Benedict Equation

Men = 66.5 + (13.75 x weight in kg) + (5.003 x height in cm) - (6.775 x age in years)

Women = 655.1 + (9.563 x weight in kg) + (1.850 x height in cm) - (4.676 x age in years)

Daily calorie/ energy requirement = RMR (per day) x Activity Factor

            

RMR can be calculated using the above four equations. The responses can be varied from each method, but the RMR lies somewhere close to the calculated amount.

Daily calorie/ energy requirement = RMR (per day) x Activity Factor

Activity factors are given for various activities per unit time.

Sleeping 1.0

Sewing 1.1

Office work 1.2

Washing plates 1.5

Sweeping 1.7

Cooking 1.8

Walking 2.8

Planting seeds 3.1

Washing clothes 3.2

Pounding grains 5.6

Playing football 6.0

Chopping wood 6.1

Digging ground 6.5

Walking up a hill with a load 8.8

Example - Calculate the energy requirement of a male weighing 75kg. The activities are given below.

Let’s calculate the RMR per hour using the general formula.

RMR per hour = 1 x 75 = 75kCal/ hour

Activity	Activity Factor	Duration	Energy requirement
Sleeping	1.0	8 hours	1.0 x 75 x 8	600
Office work	1.2	9 hours	1.2 x 75 x 9	810
Walking	2.8	2 hours	2.8 x 75 x 2	420
Cooking	1.8	3 hours	1.8 x 75 x 3	405
Relaxation time	1.4	2 hours	1.4 x 75 x 2	210
		24 hours	2445kCal

Method 2

Besides giving separate activity factors for different activities, common activity factors are given based on the physical activity level.

Daily energy requirement = RMR x factor for Physical Activity Level (PAL)

Light - office workers, students

Moderate - shop assistants, homemakers, trade men

Heavy - farmers, laborers, steelworkers

Approximate energy expenditure corresponding to PAL (ages 18 - 60)

	Light	Moderate	Heavy work
Male	1.56 x RMR	1.78 x RMR	2.10 x RMR
Female	1.55 x RMR	1.64 x RMR	1.82 x RMR

Conclusion

In this article, the main focus was on the daily calorie requirement, factors affecting the calorie requirement of an individual, means of calorie expenditure and, calculation of daily calorie requirement.