THE DIET PROBLEM FOR MOUNTAINEERS IN THE HIMALAYA

DR. G. A. J. TEASDALE

For some years I have been trying to develop a diet suitable for mountaineers in the higher Himalaya. Lieut. J. Waller has led a party on several occasions in the Karakoram range and I have been able to design a diet, study their reports, and so be able to judge the merits of their various foodstuffs.

I was led to tackle this problem from a scientific point of view after reading and discussing with mountaineers their various ideas on their food requirements. Two points struck me in these discussions : firstly, the extreme unpalatability of some of their products, and secondly, that most of their ideas were based on the diet lists of Arctic explorers. This latter to my mind is an entirely different problem. In fact, there are several problems around mountain diets which need approaching from a more scientific attitude than is usually applied to them. These I propose to discuss before going on to a particular diet.

First, what is the object of our special diets? On a mountain of any height we need food having the following characteristics:

1. It must be compact and be all food, i.e. its air-spaces must be few and its water content must be low.
2. It must keep well and be easily transported. It may have to travel from England, through the hot plains, and into a very cold region with a very reduced barometric pressure. Its packing must be able to stand rough usage, from falling into a river when a pack pony slips off the track, to being used as a seat.
3. It must be palatable.
4. It must contain the greatest number of calories per pound weight conducive with perfect health.
5. It must be easily handled in cold weather.
6. It must fit the physical requirements of the climbers.

It is this last characteristic which I think is most important, because mountain-climbing conditions are not Arctic conditions. In discussing this point it will be well to see first in which way these conditions differ.

An Arctic explorer has to contend with great cold and great effort, in other words, to do a great many foot-pounds of work, at sea-level. Now a mountaineer on a mountain above 20,000 feet has certainly to contend with great cold, but, in spite of what he may feel in the way of fatigue and exhaustion, his energy output is much less. A climb of 1,000 feet on an easy slope at 24,000 feet in one day can be a very formidable performance, but the actual work done in footpounds is often going to be less than that done by a sedentary city worker in journeying to and from his office.

The question of foot-pounds of work done, therefore, is not the real problem; it is the amount of fuel available, i.e. oxygen. Our bodily requirements in this question of fuel is a question of combustion. We get our energy, our vitality, and our heat by burning up food in our system, i.e. by combining proteins, fats, and carbohydrates with the atmospheric oxygen; it is the oxygen supply on a high mountain which is vital. To take an example, an average man needs 3,500 calories from food each day, more if he is doing very strenuous work. Suppose he eats in the course of a day one pound of average bread, practically all carbohydrate, this in combination with oxygen is burnt up in the body, giving about 1,000 calories, chiefly turned into energy, and the resultant products escape via the lungs and kidneys as C0₂ and water. Fortunately from an energy point of view carbohydrates contain sufficient oxygen in their molecules to oxidize their hydrogen, but fats and proteins need a great deal of atmospheric oxygen. Since we only retain about 4 per cent, of inspired air at sea-level, it follows that we have to do quite a lot of extra breathing on a high mountain with its lower barometric pressure and less oxygen available. Hence food metabolism is inherently connected with the available supply of oxygen retained in the system. On a high mountain this is just what we lack, and incomplete oxidization of food, being worse than useless, is in my opinion the basis of mountain-sickness and other similar troubles at high altitudes. I therefore conclude that we should seek a diet demanding as little oxygen as possible.

One factor in this oxygen shortage seems to me due to the excessive coldness of the air breathed. We obtain our bodily needs of oxygen by the air coming into contact with the capillaries or tiny blood-vessels in the lungs. It is a fact that cold causes all capillaries to contract, hence our depleted supply of oxygen on a mountain is made worse for a climber by having a smaller area of capillary available to take up oxygen.

I wish some light, simple, and comfortable device could be made to warm the air before breathing it in, something like the service gasmask and container with the container emptied and worn inside the windproof or next the skin. I think the air thus breathed would materially assist the climber.

Roughly speaking, we need food comprising proteins, fats, and c arbohydrates. Proteins are necessary to replace worn and used tissue, fats to generate heat, and carbohydrates to develop energy. Neither fats nor carbohydrates can replace proteins as the structural food for repair and replacement. An excess of protein, however, cannot be utilized; it cannot be stored, since man is not a carnivora. The nitrogenous part is excreted as urea and throws unnecessary work on the organs of digestion and excretion, and the non-nitro- genous part is used similarly to fats and carbohydrates.

Fats and carbohydrates can, within limits, replace each other. Fat is a very concentrated food, while carbohydrates are bulky. Carbohydrates are burnt up extremely quickly, so that the fire needs frequent stoking. Fats are acted upon much slower, but the body's capacity to deal with fats is limited; more than 5 oz. per day at sea-level cannot be successfully dealt with. Excess leads to autointoxication or biliousness; this is because it is not completely oxidized and poisonous products are formed. Now we want fats on a high mountain to supply heat, but fats need a great deal of oxygen to burn them up and it is just this oxygen that we lack and to get which we have to breathe so hard. Fortunately carbohydrates can be converted into fats and stored in the body as a reserve.

From this reasoning it seems that carbohydrates at frequent intervals should form the greater portion of our diet, in spite of its bulk.

It is, of course, all very well talking about food, but health must also be a vital consideration. We seem to have three serious troubles on a mountain—deterioration, mountain-sickness, and diarrhoea. In my opinion faulty diet is the basis of all these troubles, perhaps not wholly, but very largely. I may be wrong, but I see the following cycle—loss of appetite—partial starvation—metabolism of climbers' tissues (loss of weight)—acidosis—vomiting—distaste for food—and so on in a vicious circle. If we try to break this circle we must prevent acidosis. This is caused by an excess of fats and acid- forming protein, together with a deficient diet for the work done, which leads to tissues being used up to supply the deficiencies.

It is interesting here to note that raisins and sugar are amongst the highest of alkali-producing foods, having 22-8 and 31-6 c.c. respectively of equivalent alkali per 100 grammes of foodstuffs, while eggs contain 32-6 c.c. of acid equivalent per 100 grammes of foodstuff. Our bodies as a whole should be predominantly alkaline.

The indications from this seem to point to: Firstly, a sufficient diet, palatable and frequent meals so that the bodily tissues are not sacrificed, and the inclusion of raisins and much sugar; secondly, the limiting of proteins and fats. I know that this limiting of proteins will not find favour with all climbers, but the idea of a large protein diet has been, in my opinion, the result of copying Arctic diets where there is bound to be a large consumption of tissues due to the great exertion required. Surely we can keep to a low protein intake, since a diet such as I have tried to design is solely for use at high altitudes, i.e. above base camp. Normal diet should be taken up to base camp and whenever returning to it for a rest.

I know that there is a psychological element in high climbing, but to diagnose a psychological cause to many complaints is often the refuge of the destitute, and I prefer to look for a practical cause to explain deterioraticm, diarrhoea, and vomiting. Individuals vary, but generally an excess of fats will cause diarrhoea, and deterioration will be largely reduced by variety in meals, correct proportions, frequent snacks, and palatability.

Before going on to more details of diets, there is one important point to discuss, namely fluid intake. On a frozen mountain, water is hard to come by. It takes a lot of snow and Meta and time to make enough, and then it tastes horrid. In reply to questioning, climbers often tell me how small their excretion of urine is, and what a high colour it has. It must be remembered that nothing can be excreted from the body in the way of poisons from exertion or fatigue or of the amino acids from tissue or protein metabolism except via the kidneys and in water solution. An inadequate water-supply is enough to cause fatigue and lassitude, and very often head-ache and other bodily upsets, including loss of appetite, are put down to psychological factors, height, diet, or discomfort. The products of exertion will clog the system until washed away, and no individual can feel fit and give his best with his system clogged with a lot of poisonous debris. Drink, therefore, should be taken whenever possible. On a sunny day, high up on the Himalaya, it is surprising how hot one can become and how one can or would perspire if only one's body fluids were sufficient.

This water-supply needs going into more thoroughly and quite a considerable amount of water can often be obtained fairly easily. During the day water can nearly always be found by digging in the snow at the foot of a large projecting rock, or by throwing snow on to the face of a large projecting rock in the sunlight and collecting the water as it trickles down. A dark rock has the power of absorbing a surprising amount of solar heat; empty food tins, if given a coat of lamp black before starting, can absorb quite a lot of heat and melt snow quickly and so save Meta fuel. Such water can be consumed in the form of tea, with Glaxo, chocolate, or as soups; but my point is that fluid must be taken in some form in quantity to ensure the proper irrigation of the system.

I am often asked about vitamins, usually by people who know little about them. Many think the question can be neglected, assuming that the system has stored sufficient, or that the food contains enough, or that the comparatively short time high up and the plentiful sunshine render the problem negligible. This is only partly true. Vitamin A can be neglected, but B and G are worth considering. Both are largely destroyed by cooking and a mountain diet is often short of both.

Vitamin B, the anti-beriberi factor, is essential to the efficient functioning of the digestive tract where it has a specific action. This is the vitamin most likely to be deficient and the most essential to have. It is found naturally in milk, eggs, whole meal bread, and yeast.

Vitamin C, the anti-scorbutic factor, is found in vegetables, especially in orange and lemon juice, lemon juice being richer than lime juice.

There are many more vitamins needing quite a lot of the alphabet for names, but their discussion is out of place here. I do feel, however, that vitamin B is very deficient in many diets. Its digestive and curative function is beyond doubt. I had recently in my care a climber so septic from wet gangrene due to frost-bite that I anticipated his death from septicaemia. That he recovered from his septic condition perfectly and quickly was largely due to vitamin therapy.

Fortunately vitamin B is easily supplied and in many easy and palatable ways. Yeast is the easiest medium of supply. On several expeditions I have recommended a yeast product known as Yesta- min, made by the English Grain Company, Ltd., Shobnall Road, Burton-on-Trent. This is made in three forms, as a tablet, as an extract (looking like meat extract), and as a powder. I have used Yestamin yeast tablets, Yestamin and cocoa powder, Yestamin Malted Milk tablets, and the extract. The tablets are fairly hard, will keep, and a few can always be carried in the pocket loose.

The powder, Yestamin and cocoa, 'makes a grand drink', to quote a climber. I think the extract is most valuable. It makes an excellent soup and can be spread on bread or biscuits. Although being entirely vegetable it has a meaty flavour and was much appreciated as soup by all of us. I think this entirely solves the vitamin B question.

Amongst other details of diet interest which I think valuable are ginger biscuits. They are concentrated, keep well, and are very palatable. Their calorific value is extremely high, over 2,000 calories per pound, and they are a very complete food, containing all three essentials, proteins j fats, and carbohydrates. I say that they are palatable, though I should add that one climber, whom I know and who had to live entirely on them for more than a fortnight, says he can never look one in the face again. Nevertheless, he was very fit at the end, though doubtless one can have too much of a good thing.

Sugar is such a valuable food, being pure carbohydrate, that it must form a large part of a diet; moreover, natives like it. Again, the complaint has been made that a concentrated high-altitude diet is too sweet for some and that climbers crave for something having a meaty flavour. This sweetness I have got over to some extent by having shortbread, a very rich and concentrated food, made with dextrose instead of glucose. It is not nearly so sweet and is of equal value. This was kindly made for me by Messrs. J. Lyons & Co. in various flavours, malt, ginger, almond, and vanilla, and packed in sealed tins. Many climbers desire meat and yet cannot digest bully beef; it must be remembered that this is a prohibited article of import in some places. Tinned mutton, however, may take its place and has no contra-indications.

Cheese is a valuable, non-sweet food, keeps well, and is concentrated; its calorific value is about 1,900 per pound. A great disadvantage is the difficulty of removing the silver paper with gloves on.

Chocolate is, of course, a great stand-by, having a calorific value of no less than 2,515 calories per pound. It contains, however, 141 grammes of fat per pound, so should not be taken in excess since a great deal of butter will also be eaten and, with the other fats in the diet, may place the fat content too high for health.

In the experience of three expeditions Glaxo full cream has been very acceptable. It makes a good drink and can be spread on biscuits, is very concentrated, and does not require cooking.

I have no use for alcohol as a food on a mountain except in an emergency. Its action dilates the peripheral circulation and gives a false sense of warmth, but its reaction is greater than its stimulation. Off a mountain it is a different story.

There are drugs which have a definite stimulating action with little or no reaction, caffeine, benzadrin, &c., and which counter fatigue, but I do not want to discuss them here. Individuals vary in their reaction to them and some produce undesirable symptoms in certain people if taken in excess of their tolerated dose. They should be issued only by a doctor. I have, however, used some with advantage in cases of great exhaustion when an effort must be made. Nevertheless, although drugs are out of the province of this article, there is one I should like to mention. Sleep is often difficult high up. The mind will not rest, anxiety persists, and the desired sleep is not achieved. In these cases a tablet of some sedative or mild hypnotic is indicated when finally in one's sleeping-bag. It may be as mild as one aspirin to give a restful night's sleep.

Finally, before I go on to a definite example of a diet, there is one item which will appeal to most. It is that a reasonable diet is also a cheap diet and expensive products are not necessary. This is a point of some importance when so many small expeditions are going out with little financial backing.

From the foregoing it should be easy to concoct a diet suitable for any expedition. In doing so I estimate the number of days the expedition expects to need high-altitude rations and then allow an ample margin for loss, abandoned boxes, bad weather, delayed return, and then multiply by the number of persons for ordering in bulk. This can then be later packed as convenient for porters into seven- or ten-day lots. Aim at variety, as the element of surprise in a food-box often helps a jaded appetite.

The following is a diet which the climbers all tell me worked well and satisfied everybody on a recent expedition. It was designed for five white men and seven or eight Sherpa porters, and the maximum length of time a high-altitude ration would be needed, allowing for all delays, was twenty days. It will be noticed that the ration is practically interchangeable between Sherpas and climbers. There can be no two opinions that it pays to feed and equip porters as well as the climbers. The shortbread was in four flavours, but the biscuits were not all ginger-nuts, or the calorific value would have been over 2,000 calories per pound. I favoured a quantity of real plain biscuits, rather like ship biscuits. They are a useful non-sweet medium on which to spread various things.

High-Altitude	Rations.	Total 100 white-man-days
Glaxo	12 lb.	27,720 calories
Chocolate	12 „	31,332 ,,
Butter	12 „	42,036 ,,
Cheese	15 ,,	29,085 ,,
Shortcake	30 ,,	72,000 „
Raisins	16 „	14,400 „
Biscuits	16 „	26,768 ,,
Barley sugar	10 „	18,500 ,,
Corned mutton	20 „	25,600 „
Ham	12 „	29,736 ,,
Bacon	6 „	14,868 ,,
Tinned fish	16 „	16,000 „
Fresh mutton	4 ,,	6,000 „
Jam	4 ,,	5,2oo ,,

 

Total 185 lb. 359, 245 calories

Total calories per man per day: 3,600 calories

Total weight per man per day: i-85 lb. (withoutpacking)

 

One item needs explanation. It is the custom of this party to take live sheep and chickens up to their base camp. These can be killed, cooked, and taken up the mountain and will keep quite a time in the cold conditions. Of course, this cannot be done at all mountains, but a base camp farm-yard is a good asset and is well understood by all natives of Baltistan.

Total rations taken for 100 white-man-days and 150 native-man- days were:

Glaxo	30 lb.	Ham	12 lb.
Chocolate	30	Bacon	6
Butter	30	Tinned herrings	16
Cheese	15	„ mackerel
Shortcake	30	„ salmon
Raisins	40	„ sardines
Biscuits	40	Fresh mutton	10
Barley sugar	10	Jam	10
Sugar	10	Tabs. Yestamin, &c.	12
Corned mutton	40	Tea	10
Other corned meat	10	Miscellaneous	10

 

Total weight 371 lb.

Total Calories 658,429

Calories per lb. weight 1,800

 

Up to base camp the porters ate their usual food but afterwards took to the ration and enjoyed it.

It will be noticed that all these items can be transported anywhere, that they will keep, and that they can be packed to stand any amount of rough handling. It may be criticized that tins make heavy packing; but they are necessary. Perhaps the diet was too sweet, and perhaps there was too small an area on which to spread jam, Glaxo, See.; but any other vehicle would be too bulky to give the necessary calorific value for its size. I think myself that the ration of jam might have been increased.

This diet kept everybody in perfect health. None had bowel or sickness troubles, and although two members were seriously injured by frost-bite—one with wet gangrene was so septic that I had to remove all his toes and most of his fingers—yet they were evidently in such good condition that they recovered quickly their health and spirits. In fact, the health of the whole party was extremely good. The only trouble of any sort, apart from accidents, was one sore throat, a relic of the dust of the hot Indus gorge.

I hope this short, rather rambling article will stimulate climbers to take a serious interest in their own diets and not follow slavishly many of the older ideas which I am sure are not at all suitable to the higher Himalaya.

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