Living a regular life, in one place most of the time, people get to know what foods they like and dislike, and they base a balanced diet on this rather than on textbook nutrition. The problem is, how do you ensure you will have good food on the move? When travelling, you are faced with new foods and can easily lose track of how you are eating, simply because your rule-of-thumb menu-planning breaks down. This can lead to fatigue, a lack of energy and even poor health.

Eating nutritiously

Essentially there are two ways of coping. You can either pick up local food as you travel, or you can take with you all your needs for the duration. Eating local food may give you a feeling of being closer to a country's way of life, but could also make you severely ill. Taking your own supplies is safe and very necessary if you are going into the wilds, but how do you stop your palate becoming jaded with endless supplies of dried food?

It is sensible to be able to recognise the constitution of all foods and to know what is necessary to keep you well fed. A balanced diet breaks down into six main areas: sugars, carbohydrates, fats, proteins, minerals/vitamins/salts and water - all are necessary, some in greater quantities than others.

Though it is important to have some sugars in your diet, try not to depend on them. Weight for weight they give you fewer calories than other foods. Also, if you take in lots of sugars at once, the body will react by over-producing insulin because your blood sugar is too high, so that in the end your blood sugar is taken down to a lower level than before. If you desperately need instant energy, try to take sugars with other food types to prevent this happening. While travelling, it is simple enough to recognise foods with lots of sugars - they are sweet. In less developed areas, sugar is still something of a luxury, so there will be less temptation.

Fats: Next to carbohydrates, most of our energy comes from fats. Our bodies store energy as fat, because it is the most efficient way to do so. Weight for weight, fats give you nearly three times the energy of carbohydrates, so they are an extremely efficient way of carrying food energy.

Fats, of course, are fatty, oily, creamy and sometimes congeal. Foods high in fat include butter, dairy foods, etc., although there are other high fat foods that are less well known, such as egg yolk or nut kernels. Fats are necessary now and again because one reclusive vitamin is generated from a fat and, more obviously, because without these concentrated doses of energy it would take a lot longer to eat all the food you need, as with cows or elephants.

Protein is used to build and repair bodies, so children need plenty of it, as do adults recovering from injury. Otherwise, the amount of protein needed each day is small - maybe a small egg's worth. Other than that, protein cannot be readily used for energy, and the body does not bother converting it unless it is heading for a state of starvation. Those people on a red meat diet are using very little of the protein it contains, relying on the fat content which can be up to 45 per cent. When you are wondering where protein appears in your food, bear in mind that protein is for growth, so young mammals have protein-packed milk, unhatched chicks have their own supply in the meat of an egg, and to help trees off to a good start there is a healthy package of protein in nuts.

In the normal diet, most of your minerals and vitamins come from fresh fruit and vegetables. If you feel that you may not get enough fresh food, take a course of multivitamin tablets with you for the duration of your travels. They do not weigh very much and can save you lots of trouble.

If you are getting your vitamins and minerals from fresh foods, remember that they are usually tucked away just under the skin, or in the skin itself. Polished and refined foodstuffs have lost a lot, if not all, of their vitamins, minerals and fibre.

As regards salts, there is little cause for concern. It is easier to take too much than too little, and if you do err on the low side your body tells you by craving salty foods. Do not take salt tablets, you could upset your stomach lining.

How much to eat?

Nutritionists have a term for the amount of food energy needed to keep a body ticking over - the basal metabolic rate. Take a man and put him in a room at ideal temperature, humidity, etc., and make sure he does no work at all except stay alive, and he will use about 600 kCal in a day. This is his basal metabolic rate.

Those of us who do not lie stock still in a room all day need energy over and above that basic amount, to work and to keep warm. For living and working in average conditions, our daily energy requirement rises to about 2500 kCal. If you are going to be physically active (backpacking, say) in a temperate climate, your energy use will go up to around 3500 kCal per day. If we do the same hard work in an extremely cold climate, our energy rate could go up to 5000 kCal. To require more than this, we would need to do an immense amount of work or have an incredibly fast metabolism. Sadly for women, they do not burn up nearly as much energy doing the same work as men.

A little experience will tell you whether you need a little more or a little less than the average. With this knowledge, you are ready to plan just how much food you need to take for the number of days you are travelling. When you come to work out amounts of various foodstuffs that make up your calorie intake for the day, books for slimmers or the health conscious are invaluable. They list not only calories, but often protein and other nutritional breakdown. Nutritional information is also given on the packet of most foodstuffs.

Eating safely

Before handling food of any kind, always wash your hands in water that has been chlorinated or otherwise purified. This is especially important in developing countries when you may have been in contact with unhygienic materials.

Eating in developed countries is not entirely hazard-free. You should remember that Delhi Belly is no respecter of language and is just as likely to strike in Spain as in India. The rules for avoiding tummy trouble are: stick to foods that are simple and hygienically prepared, and as close as possible to those you know and love - at least until your digestive system slowly adapts to change.

Always look for food that is as fresh as possible. If you can watch livestock being killed and cooked or any other food being prepared before you eat it, so much the better. Do not be deceived by plush surroundings and glib assurances. Often the large restaurant with its questionable standard of hygiene and practice of cooking food ahead of time is a less safe bet than the wayside vendor from whom you can take food cooked on an open fire, without giving flies or another person the chance to contaminate it.

Buying foodstuffs: the rules

·Rice and other grains and pulses will probably have preservatives added to them. These will need to be removed by thorough washing as they are indigestible.

·In developing countries, canned, powdered and dried foods are usually safe to eat, provided they are made up with purified water. Staples such as flour and cooking oils are nearly always safe.

·Meat, poultry, fish and shellfish should look and smell fresh and be thoroughly cooked, though not over-cooked, as soon as possible after purchasing. They should be eaten while still hot or kept continuously refrigerated after preparation. Protect freshly bought meat from flies and insects with a muslin cover. Eggs are safe enough if reasonably fresh and thoroughly cooked.

·It is wise to avoid steak tartare and other forms of raw meat in the tropics, as there is a risk of tapeworm. Meat that is just 'on the turn' can sometimes be saved by washing it in strong salty water. If this removes the glistening appearance and sickly sweet smell, the meat is probably safe to eat.

·Cold or half-warmed foods may have been left standing and are therefore a risk. Boil such meats and poultry for at least ten minutes to destroy bacteria before serving. Remember that hot spices and chillies do not sterilise meat.

·Milk may harbour disease-producing organisms (tuberculosis, brucellosis). The 'pasteurised' label in underdeveloped countries should not be depended upon. For safety, if not ideal taste, boil the milk before drinking. (Canned or powdered milk may generally be used without boiling for drinking or in cooking.)

·Butter and margarine are safe unless obviously rancid. Margarine's keeping qualities are better than those of butter. Cheeses, especially hard and semi-hard varieties, are normally quite safe; soft cheeses are not so reliable.

·Vegetables for cooking are safe if boiled for a short time. Do check, though, that on fruit or vegetables the skin or peel is intact. Wash them thoroughly and peel them yourself if you plan to eat them raw.

·Moist or cream pastries should not be eaten unless they have been continuously refrigerated. Dry baked goods, such as bread and cakes, are usually safe even without refrigeration.

·Ice-cream is especially to be avoided in all developing countries.

·Fruit juice is safe if pressed in front of you.

In restaurants, the same rules apply for which foods are safe to eat. Restaurants buy their food from shops, just as you would.

Off the beaten track

There is no right menu for a camping trip, because we all have slightly different tastes in food and there is an almost endless number of menu possibilities. So, what should you pack? Here are a few points you will want to consider when choosing the right foods: weight, bulk, cost per kg.

Obviously, water-weighted, tinned foods are out. So are most perishables - especially if you are going to be lugging your pantry on your back. You will want only lightweight, long-lasting, compact food. Some of the lightest, of course, are the freeze-drieds. You can buy complete freeze-dried meals that are very easily prepared: just add boiling water and wait five minutes. They have their drawbacks, however. First, they are very expensive. Second, even if you like these pre-packaged offerings, and many people do not, you can get tired of them very quickly.

A much more exciting and economical method is to buy dehydrated foods at the supermarket and combine them to create your own imaginative dinners. Dried beans, cereals, instant potato, meat bars, crackers, dry soup mixes, cocoa, pudding, gingerbread and instant cheesecake mixes are just a few of the possibilities. But do not forget to pack a few spices to make your creations possible.

Most people tend to work up a big appetite outdoors: about 0.9 kg to 1.2 kg of food per person per day is average. How much of which foods will make up that weight is up to you. You can guess pretty accurately about how much macaroni or cheese or how many pudding mixes you are likely to need.

Last, but not least, what do you like? If you do not care for instant butterscotch pudding or freeze-dried stew at home, you will probably like it even less after two days on the trail. And if you have never tried something before, don't take the chance. Do your experimenting first. Do not shock your digestive system with a lot of strange or different new foods. Stick as closely as possible to what you are used to in order to avoid stomach upsets and indigestion. And make sure you pack a wide enough variety of foods to ensure you will not be subjected to five oatmeal breakfasts in a row or be locked into an inflexible plan.

After purchasing your food, the next step is to re-package it. Except for freeze dried meals or other specially-sealed foods, it is a good idea to store supplies and spices in small freezer bags. Just pour in your pudding powder, salt or gingerbread mix, drop an identifying label in, to take all the guesswork (and fun) out of it, and tie a loose knot. Taking plastic into the wilderness may offend one's sensibilities but it works well. Out in the wilds, you learn just how handy these lightweight, flexible, recyclable, moisture-proof bags really are.

Although cooking over an open fire is great fun, many areas do not allow and cannot support campfires, so don't head off without a stove. When choosing a stove, remember that the further off the beaten track you go, the more important size, weight and reliability become. Aside from a stove, you will also need a collapsible water container, means of water purification, and a heavy bag in which to store your soot-bottomed pans. You will need individual eating utensils: spoon, cup and bowl will do. Also take a few recipes with you, or learn them before you leave. You can even have such luxuries as freshly baked bread, if you are prepared to make the effort. Here are some tips about camp cooking, learned the hard way.

1. Cook on a low heat to avoid scorching.

2. Taste before salting (the bouillon cubes and powdered bases often added to camp casseroles are very salty: don't overdo it by adding more).

3. Add rice, pasta, etc., to boiling water to avoid sticky or slimy textures and add a knob of butter or margarine to stop the pan from boiling over.

4. Add freeze-dried or dehydrated foods early on to allow time for rehydration.

5. Add powdered milk, eggs, cheese and thickeners to recipes last when heating.

6. When melting snow for water, do not let the bottom of the pan go dry or it will scorch (keep packing the snow down to the bottom).

7. Add extra water at high altitudes when boiling (water evaporates more rapidly as you gain altitude) and allow longer cooking times - 20 minutes at 1000 m, for example, as against ten minutes at sea level.

Cleaning up: soap residue can make you sick. Most seasoned campers, after one experience with 'soap sickness of the stomach', recommend using only a scouring pad and water. Boiling water can be used to sterilise and, if you have ignored the above advice, is good for removing the remains of your glued-on pasta or cheese dinners. Soak and then scrub.

Use these recyclable plastic bags to store leftovers and to carry away any litter. Leave the wilderness kitchen clean - and ready for your next culinary delight.