Protein is important to the body as it is involved in growth and repair and is needed amongst other things, for the manufacturing of important body proteins such as haemoglobin that carries oxygen to cells in blood and immune proteins needed to fight infection.
Protein provides the body with 16.7KJ (4Kcal) per gm, and is sometimes used to provide energy although this is not its primary function. It is found in many foods of both plants and animal origin. To ensure that the body can use the protein it is essential to mix the types of proteins at meal times particularly if you are vegetarian. Animal proteins can be used by the body on their own but plant proteins have to be mixed, for instance by combining grains with pulses, eg beans on toast.
It is estimated that 100% of energy used during exercise comes from protein. Under extreme conditions, eg starvation or very high-energy expenditure, much more powerful protein would be used for fuel. Excess protein from the diet that is not used by the body is converted into fat. 1.0 – 1.2 grams of protein per kilogram of body weight per day is the required amount needed for a healthy diet.
Fat is a very concentrated source of energy providing us with 27.6KJ (9kcal) per gram. A diet high in fat that is greater than 35% of total energy intake is harmful to health in the long term, and is associated with heart disease, obesity, and cancer. It is essential in the diet and provides us with fat-soluble vitamins A, D, K, and E that perform specific functions in the body.
Fatty meals take longer to be digested and create a feeling of fullness. Consequently at the end of a day’s activity, a hot meal containing some fat will be satisfying and prevent feelings of hunger for a while.
In exercise, skeletal muscles will use carbohydrates and fat as fuel. Initially carbohydrates will be used and after a short time a mixture of carbohydrates and fat. The more trained the muscle, the more capable it is at utilising fatty acids for fuel and hence sparing glycogen and allowing you to exercise for longer. If glycogen becomes depleted, fatty acids alone cannot provide sufficient fuel and fatigue will become apparent.
A good source of fat is in red meats and in most other foods. Fats should be take in moderation, it has been proved that westerners eat too many, easily accessible fatty foods.
Carbohydrates are found in nature in varying forms, monosaccharides (eg, glucose) that have the smallest molecules to polysaccharides (eg, starch), which have the largest, providing the body with 15.7KJ (3.75Kcal) per gram. These different types of carbohydrates are referred to as simple and complex carbohydrates respectively. Together they should provide us with 60 – 65% of our total energy intake. *1
Simple sugars such as table sugar, honey, and fruit sugars are digested easily by the body and pass into the blood stream a short time after eating. Starches on the other hand such as bread, rice, and pasta have to be digested by the body and broken down into simple sugars before they can be absorbed into the blood stream. Starches are beneficial in exercise and help to sustain activity if they are eaten in the correct quantity.
Excess glucose, the product of carbohydrate digestion, is stored in the muscles and liver as glycogen. Once the body’s glycogen stores are full, excess glucose is converted into fat and is stored in the body. The amount of energy that can be stored by the body in the form of carbohydrates is small.
Vitamins and minerals are required by the body in minute quantities to perform specific functions and they are known to be essential for life.
‘Vitamins may be classified as water soluble or fat-soluble. In excess, vitamins can be toxic, particularly fat-soluble ones. As we have a large store of fat-soluble vitamins in our bodies, supplementation is very rarely required. If the quantity of food eaten is poor, that is highly processed food, vitamin deficiencies may occur.’ *2
Minerals such as iron and zinc are important in exercise; iron is needed for the production of haemoglobin that carries oxygen to the working muscles. Iron can be found in red meat, eggs, and some vegetables.
‘Zinc is a trace element that is involved in energy releasing reactions and is an essential component of some enzymes. The richest source of zinc is found in oyster, but can also be found in red meat and seeds.’ *3
Fibre is important to every day health as they facilitate normal gut functions and prevent the bowel from becoming sluggish resulting in constipation and diverticular disease. There are two types of fibre; soluble and insoluble fibre, both of which are needed to be eaten in the diet. An insoluble fibre comes from cereals and grains and soluble fibre is found in fruit, vegetables, and pulses. Fibre gives the sensations of fullness and leaves you feeling bulky, in exercise you do not want this. ‘Normally 30gm of fibre is recommended but it would not be harmful to health if this was reduced for a short period of time.’ *4
Water is needed to remain healthy; an average mail should drink 2.1 litres of water a day. During exercise, this may double, especially if exercise took place in hot climates.
Water is required by the body to maintain body temperature. When we exercise the body produces sweat on to the skin and it is the evaporation of this sweat that cools the body down. All the fluid lost in sweat has to be replaced by drinking fluid. If the body is dehydrated the heat will not be as effectively dissipated and heat exhaustion may occur due to a rise in body temperature.
You should never wait until you are thirsty while exercising before you decide to drink. ‘Thirst is a poor indicator of the need to drink and at this point, 1-2% of your body weight may already have been lost as fluid.’ *5 It is wise to drink small amounts frequently rather than big quantities twice a day. Suitable drinks to have whilst exercising are water, isotonic drinks, weak squash, and hot drinks.
Water is very important for the body to function; the body can go a number of days without food but only a couple without water.
It is important that we eat the correct balance of nutrients to make up our daily energy requirements. To summarise, the proportion of our daily energy intake that should come from carbohydrates, fats and proteins are 60-65%, 25-30%, and 10-15% respectively.
The best way to ensure that all sufficient nutrients are eaten is to have a varied diet. Having a wide food repertoire and eating small but frequent amounts of food will ensure that you get all the nutrients you will need.
It is difficult to say what and when to eat but there are some guidelines to what should be eaten to ensure all nutrient requirements are met. Oil, fats, and sweets need to be eaten in moderation as these have high concentrations of calories. Dairy products like cheese, yoghurt, and milk should also be taken in moderation. Two to three servings per day is ample, the same with meat products such as red and white meat, eggs and fish. Vegetables should be eaten in more abundance; three to five servings per day should be taken amongst other foods in your diet. Fresh fruit should be eaten in quantities between two and four portions a day. A simple way to look at this is to ensure five different fruit and vegetables are eaten every day, this variety should meet bodily function demands. Finally there are high carbohydrate foodstuffs. Trying to eat more complex carbohydrates is more beneficial, things such as wholemeal bread and cereals.
Water is arguably the most important of all he nutrients as 60% of our body is made from it. To guarantee our body the amount of fluid it requires we must know how much it needs. To calculate the your daily fluid requirements you do this simple calculation.
Weight (lbs) * 0.04 * 2 = volume
- (In litres)
So, my personal fluid requirement in litres per day is 3.3 litres. This is a lot of fluid to be taken by one person in one day but the importance of hydration is crucial in not only sport but in sustaining life.
Water is the transport system of our body disguised as blood; it also acts as our bodies’ temperature regulator by sweating. If the body looses 2% of body weight as water, bodily functions will be seriously compromised. A 5% loss can be fatal! At rest alone, the body can loose 2-2.5 litres a day. When training, depending on the exercise and intensity, a further 1-2 litres can be lost, this is an awful amount and can be easily underestimated by the performer. Having a healthy diet will bring in around 1-1.5 litres of water from our foods such as vegetables but lots of fluid is still needed to remain fully hydrated and healthy. When exercising we sweat, and in this sweat we loose not only valuable water but also body sugars. Drinks should contain sugars and salt to maintain body sugar hydration.
Sports drinks are easily accessible now a day and can be broken down into three main types; Isotonic, hypotonic, and hypertonic.
Isotonic are fluids that are at the same concentration as body fluids that happens to be 6g of glucose per 100ml of fluid. It is a very good source to re-hydrate the body with sugar replacements and obviously water. The drink leaves the body well hydrated if enough is drank and will get rid of thirst.
Hypotonic has a lower concentration of sugar per 100ml of fluid than blood. This means it can be quickly absorbed into the circulation after consumption; it is excellent for quick re-hydration but does not contain any or little sugars.
Hypertonic is more concentrated than body fluids, it requires dilution before it can go into circulation around the body. It replaces salts and sugars effectively but it will actually dehydrate the body, as body fluids will be needed to dilute the concentrated drink. An example of this beverage is carbonated drinks such as coca-cola and fanta or anything with large quantities of sugars in them.
As an evaluation, it is easily said that to maintain a truly balanced diet every day would be very difficult indeed. Each day brings different energy requirements and to pre-organise a weekly menu would mean that there would be no room for daily fluctuations in exercise and diet in order to maintain a truly balanced diet. Obviously no one can technically do this for a long period of time but thankfully the body is flexible and forgiving and can deal with daily variations in diet and exercise.
To maintain a health lifestyle one must try and watch what they eat and the best way to do this is to eat a variety of food rather than a few things in excess amounts. All foodstuffs are practically good for you if taken in the correct quantities but adversely they are all bad for you if taken in surplus. Water on the other hand is hard to over indulge, as the body needs so much anyone who is capable of drinking over five litres a day must be very talented or train very hard.
Bibliography.
*1 (p. 4) ‘Carbohydrates are found in nature in varying forms, monosaccharides (eg, glucose) that have the smallest molecules to polysaccharides (eg, starch), which have the largest, providing the body with 15.7KJ (3.75Kcal) per gram. These different types of carbohydrates are referred to as simple and complex carbohydrates respectively. Together they should provide us with 60 – 65% of our total energy intake.’
Taken from Mountain craft and leadership. Eric Langmuir
*2 (p. 4) ‘Vitamins may be classified as water soluble or fat-soluble. In excess, vitamins can be toxic, particularly fat-soluble ones. As we have a large store of fat-soluble vitamins in our bodies, supplementation is very rarely required. If the quantity of food eaten is poor, that is highly processed food, vitamin deficiencies may occur.’
Taken from Mountain craft and leadership. Eric Langmuir
*3 (p. 4) ‘Zinc is a trace element that is involved in energy releasing reactions and is an essential component of some enzymes. The richest source of zinc is found in oyster, but can also be found in red meat and seeds.’
Taken from Mountain craft and leadership. Eric Langmuir
*4 (p. 5) ‘Normally 30gm of fibre is recommended but it would not be harmful to health if this was reduced for a short period of time.’
Taken from Mountain craft and leadership. Eric Langmuir
