Food for extended trips
On trips of one week or longer, thorough menu planning is required to provide a well-balanced diet that will maintain good physical condition, with enough variety to boost morale and retain interest. You should plan for approximately 900 g of low moisture food per person per day. Packaging is critical—you need to consider both bulk and durability. Food should be measured out against a planned menu and bulk items (e.g. powdered milk and muesli) are better packed in one or two day group rations so they can more accurately last the distance. Effort put into planning, measuring, labelling and packing into meal serves beforehand makes meal preparation on the trip much easier if you are tired or when conditions are adverse.
Perishables should be eaten in the first couple of days or not taken at all, particularly in summer. Continental meats such as salami, cabana, smoked ham or bacon (not sliced) last quite well and should be packed in cloth rather than plastic, which sweats. Processed cheeses in foil or natural cheese in wax keep better than most plastic wrapped varieties. Margarine is preferable to butter which can go rancid. Powdered milk deteriorates in taste if kept too long.
On some trips you may use food dumps, placed in the area before the trip by the group members or a local person. As these dumps are often put in several weeks or months before the trip, they require careful planning. Perishable food is obviously unsuitable and particular care needs to be taken to protect the food from animals and vermin. Plastic drums or heavy duty plastic bags are generally the preferred containers. Burnable containers should only be used if you cannot arrange to collect drums at a later date. Drums have the advantage of providing more protection for the contents, and may contain a few cans, which must be collected with the drums.
On longer walks supplementary amounts of vitamins and minerals may be necessary. The B group of vitamins are important for the release of energy from carbohydrates, while vitamins C and E assist in providing a resistance to stress and promote tissue repair. Minerals containing phosphorous and potassium are essential to prevent cramp and fatigue, and to maintain normal muscle and nerve activity. Common salt provides sodium which is needed in heart and kidney function.
Food requirements for very long trips (more than four weeks) need to be planned very carefully to minimise the adverse impact on our bodies from the difficulties of providing sufficient nutrition to meet all requirements from food carried. This means that after about three weeks of daily activity, the body will begin depleting its stores of energy to supplement that available from the food eaten during the trip.