Determining Daily Caloric Requirement

 

Determining caloric intake is somewhat of a tricky business. Thousands of years ago we might determine our caloric requirements purely by noticing how much food we need to eat to be able to kill/harvest more food.  Today however, we know more about food and how to eat it.

A calorie is a measure of the energy potential of a given amount of digestible material.  The caloric value of a unit of food is determined by how long it will burn by itself.  In the United States it is common to see food measured against a daily requirement of 2000 calories.  Many people believe that they should base all of their caloric requirements off of the standard 2000-calorie scale that is so common, and worry about eating more or less than 2000 calories each day.  In reality the 2000 calorie scale is just a sort of baseline, or point of reference. 

The term "daily caloric requirement" refers to how many calories your body needs each day to replace the calories you burn, thus avoiding the need to consume your body for calories or the need to store up calories.  In teenagers however, our "daily caloric requirement" must also account for growth.  If we consume the ideal number of calories each day we will continue to grow.  Determining your personal daily caloric requirement means first determining how many calories you burn.   There are numerous websites and applications that can do this for you.  The basic variables that are used in the equation are:  your age, your weight, your height (body shape), your gender and of course, your daily exertion.  Although there are generic estimates available the only way to determine your exact daily caloric requirement is to calculate it based off of you unique body and lifestyle.  

Age: Age affects your daily caloric requirement because the aging body replaces muscle with fat. Fat burns fewer calories than muscle does. Also, as a teenager, you are growing, so you need calories to supply the energy needed to go throughout the day.
Body Shape/Composition: Since muscles burn more calories than fat, if you have a greater proportion of muscle to fat, your metabolism would be higher. Your metabolism is how fast you burn calories.
Gender: Typically, men have 10 to 20 percent more muscle than women. This means that they burn calories faster, so they have a higher daily caloric requirement.
Daily Exertion: When you're active, you burn calories. The more active you are, the more calories you need, or you'll lose weight. 

Teenage Girls Age	Average Calorie Needs Each Day
11-14 years	2200 calories
15-18 years	2200
Teenage Boys Age	Average Calorie Needs Each Day
11-14 years	2500
15-18 years	3000

Figure 2. UK Guidelines: Teenage and Adolescent Calorie Needs

Age of Teenage Girl	Average Calorie Needs Each Day
11-14 years	1845 calories
15-18 years	2110
Age of Teenage Boy	Average Calorie Needs Each Day
11-14 years	2220
15-18 years	2755

Source: UK Department of Health (London) 

Sources:

http://www.freedieting.com/tools/calorie_calculator.htm

http://www.dummies.com/how-to/content/what-factors-affect-your-calorie-needs.html

Post by: Brandon