By Ken Jorgustin
When planning how much food for your SHTF survival kit, or the amount of food storage in your home, or even the vegetables you might grow in your survival garden — in addition to general nutrition you need to understand how many calories that your body needs to survive and how many calories are in your food plan.
Knowing how many calories your body burns in a day will give you an idea of how many calories you should be eating (or storing) in order to maintain your energy and weight.
Your body burns calories in three different ways:
Your body needs energy to survive — even when you are sleeping. Your heart is constantly pumping, your body is working at maintaining a normal body temperature, your brain is always ‘on’, damage is being repaired behind the scenes within the body — and these body systems require fuel. Roughly 60% to 70% of the calories you burn every day is to keep all of your body systems functioning.
Your body burns calories through ANY sort of physical activity and manual labor, ranging from simply walking to strenuous physical exercise. The number of calories you burn from physical activity might range from 25% to 40% the total amount of calories you burn in a day.
Your body also uses energy to digest the food you eat, although it only accounts for about 5% to 10% of calories burned.
If you consume fewer calories than your body needs, you will create a ‘calorie deficit’ — and your body will attempt to make up the difference by depleting-metabolizing (‘burning’) your excess body fat. While this may be desirable while dieting, it is undesirable (a calorie deficiency) in a survival situation.
Calorie Requirements Vary With Physical Activity
The following two examples may give you a general idea of caloric needs and how they vary with physical activity.
A 200 pound, 6’2″ man 40 years of age who is ‘lightly active’ during a typical day will require 2,700 calories to maintain body systems function without gaining or losing weight. That same person will require 3,400 calories if he is ‘very active’ and 3,800 calories if ‘extremely active’.
A 140 pound, 5’7″ woman 40 years of age who is ‘lightly active during a typical day will require 1,900 calories, but if ‘very active’ will require 2,400 calories, and if ‘extremely active’ will require 2,600 calories to maintain body systems function without gaining or losing weight.
General Calorie Requirements
These numbers vary with gender, age, environment, physical condition and activity. There are charts and resources online to narrow down your own specific requirements, but here is a general range…
Daily Calorie Requirements
Male, 5’11″, 190 pounds, lightly active
Age-20: 2,800 calories
Age-30: 2,700 calories