An area of preparation that takes a lot of analysis and calculation is optimising the nutritional and calorific intake for during the expedition as well as throughout training. During the expedition it is crucial to find the perfect balancing act where by the team are carrying enough food and in the correct forms to sustain their journeys duration, but also minimise the total weight of the food in order to make manoeuvring over the terrain possible.

The Rivers of Ice team have been working with a nutritionist to create with the best possible ‘menu’ for this particular expedition. When calculating the exact dietary requirements, measurements such as the Resting Metabolic Rate must be taken into account. Tarka and Charlie will naturally expend different amounts of energy while at rest in a temperate environment. However, for the purpose of this page the calculations have been simplified and generalised to show the basic nutrition and calorific calculations.

Firstly to work out how many calories the team members will require in order to carry out the physical exertion of the expedition:

Using the generalised figures that a mountaineer, carrying over 40kgs of equipment in deep snow etc, will consume an average of 200 calories/Km, 400 calories/1000ft elevation and an additional 65 calories/hour RMR. Covering a distance of 560Km and 7770ft in elevation throughout the expedition, the team members will need a total of 162,000 calories each.

Through training the team concluded that the maximum safe weight for each backpack is between 40kg – 45kg (any more and the climbing/ rappelling/ crevasse sections became to unstable). Subtracting the weight of the kit, left 24kg of food per person.

Taking an average figure of expedition food providing 500 calories /100g, each team member will in fact require 32.4kg of food for the duration of the expedition. Which leaves a deficit of 8.4kg of food from the 24kg that they can carry, this equals 42,000 calories. This is by no means an ideal scenario but conditions on such demanding expeditions are far from ideal. However it is good to remember that the most important nutrition is water. The human body can survive an average of 30 days without food but only 3 days without water.

To compensate for this deficit the team will have to put on weight creating large fat reserves that the body can tap into when the expenditure becomes greater than the intake. Again using an average figure, the human body can extract 6666 calories/Kg of fat. So with the team’s deficit of 42,000 calories per team member, they will need to put on a minimum of 6.3kg in excess fat each. A task proved very difficult when carrying out large amounts of physical training.

The initial 5-7 day kayak section will have a separate, and incredibly calorific, food bag/ menu. So for the purpose of the food calculations we are only concerned with the subsequent 30 expedition days.

24kg of food shared out over 30 days gives 800g food allowance per person. Not only must this food be as high in calories and nutrition as possible but also easily prepared with the minimum of time, fuel and mess. With weight playing such an incredibly important part of the success of the expedition, the weight of fuel carried must also be kept to a minimum. With the necessity of melting snow to both drink and cook the team will only light the stove twice a day (morning and night) to reduce fuel consumption and so the food they will eat during the day will be high calorie snack bars with no cooking requirements. The calories from the food are gained in the ration of 60-65% carbohydrates, 20-25% fat and 10-15% protein.

This ratio has been specifically developed to maximise the team’s energy intake. At first glance you may ask why we have opted for 60-65% of our food energy intake to be in the form of carbohydrates when fat contains 9 cal/g when carbohydrates contain only 4 cal/g. Well in very simple terms it is because of the amount of energy needed to break down fat molecules. Because fats are considerably more complex than carbohydrates they require more energy and oxygen to convert them into a usable form of energy. In fact they require about 5 times more energy and about 4 times more oxygen to convert than carbohydrates. Carbohydrates themselves come in 2 distinct categories; simple and complex. Simple carbohydrates are generally referred to as sugars and give ‘quick fixes’ of energy as they are readily available and require almost no processing by the body. Complex carbohydrates are starches and although they need to be broken down by the body they provide a continuous and steady output to help sustain long periods of exercise.

Proteins are generally regarded as the body’s building blocks and are necessary for chemical processes within the body. Unfortunately these are often difficult to carry in autonomous expedition environments as they are both heavy and difficult to preserve.

A days food ration consists of:

A dry homemade cereal bag vacuum sealed (just add cold water on expedition) containing;

Granola mixed with fruit and nuts (calorific value = 476 calories/100g)

Dried full cream powder (calorific value = 506 calories/100g)

Anhydrous Milk Fat (calorific value = 928 calories/100g)

Desiccated Coconut (calorific value = 666 calories/100g)

Cod Liver Oil (calorific value = 1000 calories/100g)

7 x ‘9 Bar’ hemp snack bars in a variety of 4 flavours (original, nutty, flax and pumpkin) (calorific value = 562 calories/100g).

A freeze dried expedition meal vacuum sealed (just add hot/cold water on expedition) (calorific value = 400 calories/100g)

Cheese powder (calorific value = 690 calories/100g)

Totaling a minimum of 4000 calories intake per day and therefore using an additional 1400 calories from the bodies’ fat reserves.