Nutritional needs

To survive in the nature, one needs certain amount of energy. As a rule of thumb, if you lay flat in a warm and cozy place, about 5000 kJ (1200 kcal) per day should keep you alive, moderate physical activity doubles the energy requirement to about 10000 kJ (2400 kcal), and hard work increases the need of energy to about 15000 kJ (3600 kcal). Age, health status, and body weight are among the factors, which may change the energy requirements to one direction, or another. For example, a young man in late teens may need over 20% more energy than an elderly person of similar size, and fever generally increases the need of energy, where as long term shortage of nutrients may slow down the basic metabolism. Body size, fat percentage, and other individual variables aside, the most important factor changing the energy requirements (at least in the nordic regions), is the temperature; involuntary shivering in cold conditions may momentarily increase the consumption of energy by over 1700 kJ (400 kcal) per an hour. Therefore, in a SHTF situation, be honest to yourself about your needs and conditions around you, and most importantly, stay warm and calm when you begin to search for sources of energy.

However, in an emergency situation the most important stuff to be searched for is not food, it is water. Even in ideal conditions, human beings need about 2 liters (half a gallon) of water per day, and in most of the emergencies, a lot more. Absence of water begins to affect person’s physical and mental abilities, not within days, but within hours. With sufficient water resources, an average healthy person, thanks to utilization of the body fat, is capable of moderate physical activity, such as fishing, hunting, and gathering edible things, for almost a month, conditions permitting.

In the following table, I have listed the base nutrients and the first symptoms caused by a shortage of them.

Water Hours Fatigue, weakening of performance Streams, lakes, springs, snow
Carbohydrates Several days Fatigue, weakening of performance, ketosis Fruits, berries, veggies, plants, (milk, honey)
Salt Several days Fatigue, weakening of performance Sea water, rock salt (meat and some plants)
Vitamin B1 (Thiamine) Days to weeks Weakening of endurance Whole grain, liver, meat, beans, peas, veggies
Proteins Several weeks Not known Meat, fish, veggies
Vitamin C (Ascorbic acid) Several weeks Fatigue, weakening of performance Fresh berries, fruits, veggies
Vitamin B2 (Riboflavin) Months Changes in skin and mucosa Liver, meat, fish, veggies, milk
Fat Several months Not known Meat, fish, nuts, some plants
Vitamin A Several months Weakening of night vision Liver, kidneys, milk, butter, carrots, spinach, tomato, rose hip

Based on the table above, for the first couple of hours, or days, of an emergency situation, a sensible person would secure a source of water. Then it would be a time to search for carbohydrates and salt.

Source of water has never been a problem for me, but I am in an unfortunate position of being far away from salt resources, the sea is 150 km (about 100 miles) to the west, and I have never seen rock salt in it’s natural environment. Some forms of carbohydrates are to be found from late May to September, but for the rest of the year, I’m pretty much screwed.

However, the information above gives me some idea of how I should be prepared for various, more or less probable, emergency situations.

For a regular 3-5 day hiking trip, I should have food worth of about 30000-50000 kJ (7200-12000 kcal) plus some 20% for emergencies. That equals about 1.2-2 kg (2.5-4 lbs) of dehydrated carbohydrate source, such as potatoes, rice or pasta, about a similar amount of dehydrated meat, and some 300-500 g (10-18 oz) of fat. (in this equation, additional veggies, bread and such, are just extra).

In case of serious zombie apocalypse, for the first year one should have some 100+ kilos (220 lbs) of dehydrated carbohydrate sources, similar amount of dehydrated protein/fat sources, and about 40 kilos (88 lbs) of pure fat.

I’m not worried about zombies too much, but I try to keep most, if not all of the information on these pages scalable up or down for different needs.

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