You always hear people talking about the amount of calories you need to consume each day, well, that number depends on a lot of factors:
1. Activity Level
4. Body Type
5. Health Conditions
6. Medications, etc
There are tables and websites that will give you a ROUGH estimate for the amount of calories that your body burns while at rest. The brain, heart, lungs, and all that blood coursing through your body eats up calories. You will be surprised to learn just how many calories your body burns performing it's daily functions. Now, add exercise on top of that and you can start to understand how many calories you need to consume in order to 1)maintain your weight, 2)lose weight, 3)gain weight.
Resting Metabolic Rate (RMR)
Fun site to check out:
Note: BMR calculators should only be used to provide a rough guideline on daily energy expended. Actual values cannot be attained using such calculators, and may be quite inaccurate depending on several factors such as geographic location, body-type, diet, body composition, supplementation and some genetic factors. Values which extend +/- 15% above and below your calculated BMR may be a more accurate representation of your actual BMR range as daily fluctuations are constant and your BMR is rarely the same on a daily basis.
A really great website to subscribe to (one time $15 fee) is as follows:
The site helps you to understand what food you are putting into your body, how to read labels, and how much exercise you need to maintain/lose/gain.
Hope this helps! :)