How many calories are the basis for the calculation of the percent daily values?

If you pay attention to the information table of nutrient value on food packaging, then you’ll often find a statement that says, “AKG percentage based on 2000 kcal energy requirement. Your energy requirement may be lower or higher.” This means that the amount of calories you need per day differs from other people.

What is a calorie?

Before knowing your calorie requirements, it’s best to know what a calorie is. A calorie is a measuring unit to determine the amount of energy contained in foods. When we eat or drink, we give energy (calories) to our body. The body then uses that energy as fuel to run our various activities. The more activities we participate in, the more calories are used.

The number written on food packaging usually uses a “kilocalories” unit, or “kcal”. As an example, 500 calories will be written as 500 kcal. Other than kcal, calories can be written as “kilojoules” or “kJ”. One kJ equals to 0.239 calorie.

Why is one’s calorie requirement different from the other?

Calorie requirement depends on factors such as gender, age, body weight and height, body composition, activities and physical condition. Calorie needs of men and women differ, even if they are the same age. Even twins will have different calorie requirements depending on their physical condition and daily activities.

Standards of calorie intake differ from one country to another. In the US, men are recommended to consume 2,700 calories per day and 2,200 calories per day for women. Meanwhile, based on the UK's National Health Service, men are recommended to consume 2,500 calories while women only 2,000 calories. This is in contrast to the FAO, which recommends adults to consume a minimum of 1,800 calories per day. 

In Indonesia, there is a nutrient value necessities table guide, which contains a recommendation of how much calorie required by each age groups, for example:

- 7-11-month-old babies with 9 kilograms body weight and 71centimeters body height require 725 kcal of energy per day.

- 19-29-year-old men with 60 kg body weight and 168 cm body height require 2,725 kcal of energy per day.

- 19-29-year-old women with 54 kg body weight and 159 cm body height require 2,250 kcal of energy per day.

- Men above 80 years old require 1,525 kcal of energy whereas women of the same age require 1,425 kcal of energy per day.

- Pregnant women require more added energy around 180-300 ckal per day, depending on the trimester of the pregnancy. Same goes with breast-feeding mothers; in the first six months they require more energy of up to 330 kcal and an extra 400 kcal in the next six months.

(Read also: Which is more effective for losing weight: exercise or diet?)

How do I calculate how many calories I need?

There are a number of ways to calculate your calorie requirements, which are:

Harris-Benedict Formula: This formula is commonly used by nutritionists. Harris-Benedict formula takes age, gender, body weight, body height and your level of physical activities into account. Formula used to calculate men’s calorie needs is = 66.5 + 13.8 x (body weight in kilograms) + 5 x (body height in cm) divided by 6.8 x age. Meanwhile for women= 655.1 + 9.6 x (body weight in kilograms) + 1.9 x (body height in cm) divided by 4.7 x age. Result of the equation must be multiplied with your physical activity factor. If you have low physical activity, then multiply by 1.2. If you participate in average physical activity then multiply by 1.3. For people who do heavy physical activities, multiply by 1.4.

WHO Formula: Differs from the Harris-Benedict formula, this formula is simpler and does not calculate body height. WHO Formula is categorized based on one’s age. For example, to find out the needs of energy for women between 18-29 years old, we use a formula of 14.7 x (body weight in kilogram) + 496. Whereas for men age 18-29 years old, formula used is 15.3 x (body weight in kilogram) + 679. The result is then multiplied by physical activity factor.

Calorie needs and the relation to your health

Although most food packaging shows a nutrient value percentage based on 2,000 kcal energy requirement, now you know that not all people need 2,000 kcal of calories in their daily basis. Your energy needs depends on gender, age, body weight, body height, physical condition and your daily activities. Knowing your daily energy requirement can help you maintain your health because it can balance your energy intake.

The main principal in fulfilling energy needs is actually simple; it’s all about balance, because if you consume more calorie than needed, it can cause an increase in body weight in the near future aside of increasing the risk to suffer from certain diseases, especially degenerative diseases. If you consume less calorie than needed, you’ll encounter weight loss but at the same time decreasing the function of bodily organs due to the deficiency of required amount of energy. (kes)

Disclaimer: The opinions expressed in this article are those of the author and do not reflect the official stance of The Jakarta Post.

How many calories is the percentages based on?

Those percentages are based on the recommended American diet of 2,000 calories per day. Now, a person's dietary needs are as unique as their fingerprints, but this gives us something to go off of.

How are the number of calories calculated?

Calculate the energy content of the food in kilocalories/gram. Using information on the nutrition label of the food sample, calculate the kilocalories/gram. (Divide Calories per serving by the number of grams in a serving.)