Since food is the main energy source for both exercise and maintaining body temperature, it is important to eat often and wisely when bushwalking, particularly on extended or physically demanding trips.
On overnight walks, food and its preparation also contribute significantly to morale, providing a pleasant social end to a physically hard day.
A day spent bushwalking generally expends more energy than a typical one at home. So don't skip breakfast, eat a little more than usual, and have frequent snacks of high energy, easily digestible food. On overnight walks, have a generous serving of carbohydrates such as rice or pasta for the evening meal. Hot soup replaces lost salts and is an excellent starter to warm the tired body and boost energy whilst preparing the main meal.
Popular quick-acting high energy snacks include dried fruit, nuts and chocolate which, when mixed together, acquire the colourful bushwalking name of 'scroggin'. Simple but adequate lunches include bread or biscuits and cheese, with a little fresh fruit or salad/vegetables on the side. Evening meals are generally prepared from dehydrated ingredients because of weight considerations. However, a little capsicum, snow peas or bean shoots are light and can add freshness to the dish. Although today there is a substantial range in price and variety of commercial dehydrated food on the market, there is an increasing number of overnight bushwalkers who enjoy the challenge of producing their own creations with home food dehydrators.
Carry extra food in case of emergency
As a general guide, the daily water requirement of the average active person is approximately 2 litres in cool weather, rising to 5 litres in very hot weather.
Surprisingly, thirst is not always the best guide. For safety it is advisable to drink slightly more water than you appear to need, particularly in the extremes of both hot and cold weather.
The most durable water containers are made from aluminium or heavy duty BPA-free plastic. Light plastic bottles such as used soft drink bottles may burst when subject to rough use. Flexible bladders with a drinking tube (often marketed as hydration systems), that enable water to be consumed as you walk, have become very common alternatives to water bottles.
It is generally unwise to rely on finding drinking water on route, particularly in the summer months. Carry at least 1 litre in cool weather, 2 to 3 litres in warm weather and up to 5 litres in hot weather. For hard walks it is advisable to carry even more.
When planning overnight campsites, make every attempt to confirm information about the availability of water near the site. If doubtful, carry extra water from the last source of sure water before camp. Used wine or water cask bladders are ideal for this purpose.
Purifying or Treating Water
Most running water not downstream of human habitation or grazing areas is safe to drink. However, water supplies are increasingly being rendered unfit for drinking due to pollution from human and animal wastes, and require treatment. If in any doubt, water should be boiled for 1 minute (3 minutes at altitudes above 2,000m) before use.
There are various methods of purifying water for drinking while on a bushwalk. Filtering and purification are not the same thing. A water filter cleans the majority of sediment from the water. A purifier renders water free from both bacterial and amoebic pollutants such as giardia.
Iodine tablets can be used, but leave an unpleasant taste in the mouth. Many water filtration systems feature a filtration and pump system housed entirely within the bottle, so all you have to do is fill the bottle with water, pump a few times, and drink. Similarly, a LifeStraw ® filters water through a straw, to enable drinking directly from the source. Bacteria can also be eliminated using UV light in a battery powered Steri-Pen ® which is agitated in a one litre water bottle for approximately 30 seconds.