Four quick tips

Carbohydrates

1. In a training diet it is recommended that athletes consume 55-60% of the dietary intake as carbohydrates. However, the amount may vary and the type of carbohydrate will depend on whether the athlete is training, in a game or pre and post match stage.
2. Carbohydrates in the diet include starchy food such as pasta, cereals and potatoes, and sugars such as those found in honey, fruit, confectionery and jam.
3. Carbohydrates have different effects on blood glucose. Foods have been rated on their effect on glucose in the blood; this scale is called the glycaemic index (GI). If blood glucose increases quickly then it is said to have a high GI. However, if blood glucose increases slowly and sustained over a longer period then the carbohydrate food is said to have a low GI. The response of blood glucose after eating carbohydrate can also be altered by the amount of fat, protein, dietary fiber and also with the method and extent of processing of the carbohydrate food. Some examples of low GI foods are pulses, oats, bran cereals, pasta, bread (wholegrain) and vegetables (sweet potato and sweet corn). Some high GI foods are sugar, ripe (soft) bananas, honey and rice.
4. During different stages of competition and training one type of carbohydrate is preferential over another. For example carbohydrate loading requires mostly medium to low GI foods but during a match small amounts of high GI foods may be required.

See future articles for more details on carbohydrate loading and requirements for footballers.

Protein

1. Athletes should consume about 15 % protein in their diet from a variety of sources. Protein is required as a building block for muscles, tissues, hormones and cells. As mentioned previously protein is broken down into amino acids.
2. There are 23 amino acids of which most can be produced by the body. However, there are a few essential amino acids that are required from food. Therefore, it is important that protein is consumed from a variety of sources.
3. Meat, eggs and dairy products are good source of these essential amino acids. However, pulses, cereals, nuts and seeds also contain some of these amino acids.
4. For vegetarians it is important that they get their proteins from a wide variety of foods, as some of the plant proteins are deficient in particular essential amino acids.

See future articles for more details on proteins.

Fat

1. Athletes should limit their fat intake to 25-30%. This may sound like a lot but it is not when you consider the contribution fat makes to many processed foods, take away foods and its use in cooking.
2. It is recommended that where possible athletes should replace saturated fat in their diet with monounsaturated fat. This is because monounsaturated fat does not increase LDL (bad) cholesterol and there is some research that suggests it may be broken down more efficiently than saturated fat. Sources of monounsaturated fat are olive oil, canola oil and some nuts e.g. walnuts and almonds.
3. Fat has had a bad wrap over the last 10 years but it is important to remember that fat is broken down into fatty acids, which are essential for good health. In fact, the body can not produce some fatty acids; therefore, we need to consume them in our diet. Fatty acids contribute to cell membranes and the type of fat you eat influences the composition of your membranes surrounding all your tissues. Therefore, they have a role in everything from brain function to inflammatory responses during injury.
4. Fats and oils provide fat soluble vitamins (A, D, E and K) and phytochemicals in the diet.

More on fat in later articles including tips to reduce it in the diet and the contribution of fat to performance.

Vitamins and Minerals

1. It is important that athletes eat a wide variety of foods, this will ensure that adequate amounts of all the vitamins and minerals required by the body are available. All vitamins and minerals are important for good health.
2. Athletes can maximise their vitamin intake from fruits and vegetables by not overcooking their food, cooking in small amounts of water e.g. steaming, and buying fresh produce.
3. If you eat an adequate diet then you should not require supplements. Professional nutritionists, dieticians or doctors should assess athlete's nutritional status. Those that are vulnerable to deficiencies are vegetarians, persons who smoke and drink excessively, those who are on weight reduction diets, and those who are taking medication or drugs that may alter absorption of nutrients.
4. Iron status is particularly important for athletes. Iron is a component of haemoglobin. Haemoglobin's role in the blood is to carry around oxygen to tissues. Therefore, if your iron status is low then the amount of oxygen in the blood is also low. This is an important point for athletes because of your energy and oxygen requirements during exercise it is important that iron levels are kept within normal range. This point is particularly noteworthy to vegetarian athletes. Meat is a good source of iron in the diet, however, leafy green vegetables, cereals and some processed foods, with added iron, are considered to be other sources.

In the upcoming weeks we will talk more specifically about different vitamins and minerals and the importance of iron status for athletes.

Dietary Fiber

1. It is important for the regulation of digestion and absorption of foods. Good sources of dietary fiber are wholegrain bread, brown rice, lentils and wholemeal pasta.
2. Important in waste regulation and helps prevent constipation.
3. Dietary fiber adds bulk to the diet without adding energy.
4. Dietary fiber content in the pre match meal should not be increased beyond what is normally consumed as discomfort and the feeling of wanting to make a quick dash to the toilet may be desired, during the initial stages of a match or competition.

Fluids

1. Persons participating in moderate physical activity require at least 2 L of water per day but those who exercise vigorously and athletes require more.
2. Athletes must prevent dehydration especially during exercise. Footballers should be drinking fluids at least between quarters.
3. Don't drink just when thirsty, as by this time you may already be mildly dehydrated.
4. Athletes may require electrolytes and carbohydrates supplemented in fluids during and after exercise to aid absorption of water and provide energy (See future articles on sports drinks).


References.

Inge, K and Roberts, C. 1992. Food for sport cookbook: the ultimate nutritional guide for peak performance. 3rd edition. New Holland Publishers.

National Health and Medical Research Council.1992. Dietary Guidelines for Australians. Commonwealth of Australia.