The critical role of proper nutrition, and hydration in preventing accident and illness during any wilderness trip cannot be overemphasized. If you think of the human body as a soft machine, then the importance of fuel (nutrients) and engine coolant (water) become obvious.Season after season, any number of major and minor wilderness catastrophes can be traced back to the failure of backcountry travelers to eat and drink adequately, and to carry the right clothing for the conditions they are likely to encounter. The consequences of dehydration and inadequate calorie intake play a major and inter-related role in frostbite, hypothermia, shock, burns, the healing of wounds, infection, illness due to heat, high altitude illness, diarrhea and constipation.
Virtually all of our wilderness trips increase the amount of water and fuel needed for each day’s activities. Back home, working at our desks, we require roughly two thousand calories a day to maintain body weight, and to account for the day’s energy expenditure. Backcountry adventures, in one form or another, can easily increase the body’s need for fuel to four or five thousand calories a day, or more. Extreme exertion at high altitude can raise that figure significantly. That is quite a lot of freeze dried beans and rice. The same calculations hold true for our water requirements. It takes about two liters (quarts) of water to maintain a proper state of hydration over the course of a day’s work at the office. This figure only accounts for the water vapor lost through breathing, perspiration (we are always perspiring, or losing water vapor through our skin), and urination. Exertion above and beyond the sedentary minimum can double or triple our daily water requirement. This includes the water consumed in food, fruit drinks, and carried in canteens.
A balanced backcountry diet for trips below ten thousand foot altitude should include forty percent of calories derived from carbohydrates, thirty percent from protein, and thirty percent from fat. Above ten thousand feet, seventy percent of your calorie intake should come from carbohydrates, with the remaining calories evenly divided between protein and fat sources. Balancing protein, fat, and carbohydrates in this way provides your engine with a smooth and continuous flow of fuel, and allows for the storage of more calories than can be accomplished with higher carbohydrate diets. The human body can only store a few thousand calories from carbohydrate, in the form of glycogen maintained in the liver. On the other hand, we can easily store several tens of thousands of calories as fat. Protein in the diet of the wilderness adventurer serves to prevent the metabolic breakdown of muscle which takes place when energy from carbohydrates runs out. The dietary recommendations for travelers above ten thousand feet is based on a number of inter-related, and complex physiologic factors, including the increased difficulty of digesting fat at the low oxygen levels found above ten thousand feet, and the body’s need to maintain a stable acid base balance, factors not as critical at lower altitudes.
If you wait until you make camp, or feel hungry and thirsty before you eat and drink, you will always be behind in fuel and fluid balance, and will soon exhaust yourself. Prudent drivers don’t wait until the car runs out of gas and overheats to fill the radiator and gas tank. Your body deserves the same consideration, or like your car, it will fail you when you need it the most. Get into the habit of eating small amounts of food, and drinking lots of water continuously throughout the day. Time tested gorp (my personal favorite is sunflower seeds, yellow raisins, and bittersweet chocolate chips), or one of the new protein, carbohydrate, and fat balanced energy bars, bagels, salami, or jerky all work well on the trail or down the river. The specific role of nutrition and hydration in the prevention of illness and injury in the backcountry are discussed in more detail in the chapters devoted to Shock, Burns, Wounds, Heat Illness, Altitude Sickness, Hypothermia and Frostbite.
Realistically, of course, there are a number of things that might happen to you or your companions on a wilderness trip that even a trained medical expert would not be able to treat in the field, but fortunately, they are not the most common of injuries and illnesses. With knowledge and an adequate wilderness first aid kit in your pack, you can do at least some good for almost everyone you encounter who requires first aid treatment in the backcountry.