Caloric Requirements

In teens, many factors will affect the amount of calories you should and need per day. Your gender, age, weight, height, activity levels and much more will affect the number of calories you should be eating, so how will you know how much to take in per day?

First of all, a calorie is the amount of energy required to raise the temperature of 1 gram of water 1 degree centigrade. Different foods can and will contain different amounts of energy, which is why a scoop of peanut butter will have more calories than a similar sized carrot.

For vegetarian teenage girls, 1,800 - 2,200 calories should be consumed daily. For vegetarian teenage boys, 2,300 - 2,700 is the caloric requirements. You can use calorie calculators, like the one here, to find a more specific measurement about the number of calories you should intake daily.

If a teenager were to consume to many calories, it can lead to excessive weight gain. Only 3,500 extra calories can make you gain a whole pound! The reversed is also the same. However, it is not good for a teenager to limit their calorie intake. A teenager needs the calories so that their body can grow and develop. Limiting calories will affect the teen's maturation process. Calorie intake should never be lower than 1,200 calories daily for women and 1,500 for men.

Sources
http://diet.lovetoknow.com/wiki/Healthy_Diet_for_Teenagers
http://health.nytimes.com/health/guides/nutrition/diet-calories/overview.html
http://www.weightlossforall.com/calories-restriction.htm
http://www.eatindianfood.com/images/Eating-Healthy-diet-Food-Gives-Nutrition-Within-Calories.jpg