Activity, exercise and food

Active participation in sport or other forms of physical activity are an important part of development for young people, and also contributes to good health. To assist with exercise performance, young people need to pay special attention to their eating patterns, and that may require special advice. Generally, however, if a young person eats well, vitamins or other supplements will not be necessary.

Healthy eating habits for young people undertaking physical activity
All young people should eat mostly complex carbohydrates, sufficient fruit and vegetables, a moderate amount of dairy products and meat and meat alternatives, and minimise fatty foods. For serious young athletes more specific sports nutrition information is provided as follows:

Eating well is always important, but even more so when someone wants to perform well in sport events. Ambitious young people will do their best in sports events if they do the right training, have a healthy diet and are talented.

A healthy diet
A healthy diet involves:

• Eating plenty of carbohydrate foods
• Eating enough protein
• Eating lots of fibre
• Drinking lots of water
• Eating fewer fatty foods.

Eat plenty of carbohydrate foods
Carbohydrates are the human body’s fuel. Just as a car runs on petrol, the body runs on carbohydrates, particularly complex carbohydrates. A young person will need energy to undertake physical activity, and the table below suggests some of the types of food that can provide the necessary energy boost. How much a young person should eat requires specific dietary advice from a dietitian, but the minimum of five serves per day of breads and cereals is not likely to be adequate for an active young person.

The message for young people should be that eating well can enhance performance. Eating more complex carbohydrate-rich foods means having more energy. More energy means running faster, for longer,and recovering more easily.

Table 1. Sources of carbohydrates

Complex carbohydrates

• Wholemeal/multigrain bread, rice, pasta
• Some cereals - oats, wheat -based biscuits
• Potatoes, peas, sweet corn, parsnip, carrots
• Legumes - lentils, baked beans, chickpeas
• Fruit
• Milk and yoghurt.

Simple carbohydrates

Sugar, glucose, fructose, honey, syrup, jams, marmalades, toppings, flavourings, confectionary, cakes, sweet biscuits, soft drinks, flavoured mineral waters, cordials, beer, sweet wines, liquors.

Eat enough protein
Protein is the nutrient from which the body’s muscles, skin, bone and blood cells are made. Hormones, enzymes and antibodies are also made from protein. Protein is therefore important to rebuild damaged muscles and organs, and also, to a small extent, to use as energy during exercise. The table below provides some examples of good protein sources.

Table 2. Sources of protein

Complete proteins

• Meat, chicken, fish
• Milk, cheese, yoghurt
• Eggs

Incomplete proteins

• Wholegrain cereals, rice, pasta
• Legumes - baked beans, chickpeas, kidney beans
• Nuts and seeds

Most young people in Australia eat more than enough protein. Even if a young person needs more protein than the average person, it is likely that they will not need to increase their protein intake significantly. Young people who need to take special care to eat enough protein are vegetarians and those on strict weight-loss diets. See also Young men and food for further information on protein needs for young people, especially the section ‘Building muscles’.

Eat lots of fibre
Fibre helps regulate the rate of digestion and absorption. This may slow down the release of sugar from food, and therefore gives the body a steady sugar release for energy over the day. Fibre also helps keep the bowels regular, fills us up and protects the body from heart disease.

Table 3. Sources of fibre

Soluble fibre

• Wholegrain cereals, rice, pasta
• Legumes - baked beans, chickpeas, kidney beans
• Nuts and seeds

Insoluble fibre

• Wheat bran
• Corn bran
• Skins of fruit and vegetables

Drink lots of water
Adequate fluid intake is extremely important when training, in order to:

• Prevent muscle cramps
• Replace fluids lost via sweating
• Assist with body temperature regulation
• Prevent constipation as you increase fibre intake.

Other points to remember:

• Don’t rely on thirst to make you drink - by that time you are already dehydrated.
• For every kilogram of weight lost during training a litre of fluid is needed.
• Drink about half a glass of water every 10-20 minutes, several hours before exercise, and try to have fluid regularly throughout exercise.

Table 4. What to drink

What to drink

Water

Sports drinks

Soft drinks

Alcohol
Comments

Water is the best fluid to drink to replace sweat loses during training.

Carbohydrate/electrolyte drinks can be useful in long endurance events, such as marathons or triathlons.

Choose a drink that is not too high in sugar, as this will slow the absorption of fluid from the gut, which can result in bloating.

Soft drinks are very high in sugar, and this will slow the absorption of fluid from the gut, which can result in bloating.

Soft drinks can be useful after sport to top up glycogen stores in the muscles.

Alcohol does not assist sporting performance. Alcohol increases the risk of dehydration, impairs judgement, reaction time, balance, accuracy, and can also cause low blood sugar levels.

Drinking alcohol after sport can aggravate soft tissue injuries, resulting in increased bruising and swelling.

Eat fewer fatty foods
Young people’s diets are often very high in fat, due to their high intake of fried take-away foods. Eating fewer fatty foods will:

• Help control body weight
• Allow more carbohydrate foods to be eaten, which will increase energy levels
• Improve sport performance
• Reduce the risk of heart disease later on in life.

The most useful way to reduce the fat intake of young people is to provide alternative, lower-fat take-away and snack foods. Most young people do not regularly cook, especially those in transient accommodation or with drug and alcohol issues. Refer to Healthy snacks and takeaways for lower-fat take-away options.

Low-fat tips

• Always remove visible fat from meat, chicken and fish.
• Grill, steam or stir-fry foods.
• Use reduced-fat dairy products.
• Try to eat unprocessed foods, as they are less likely to contain hidden fats.
• Read food labels for fat content.
• Limit fatty foods, such as pies, pasties, sausage rolls, hot or cold chips, cakes, chocolate, biscuits, butter/margarine, cream, oils and dressings.
• Eat lots of low fat ‘fillers’, such as brown breads and cereals, fruit and vegetables, to give you energy.

A note on severe weight loss practices
Severe fasting to reduce body weight is a dangerous practice. If a young person has just started exercising as part of a weight reduction program, they should not skip meals, as this will only lead to a lack of energy and reduce essential nutrient intake. Refer to Why diets don't work.

Weight may actually increase when exercising regularly. This is quite common with some young people, due to the development of extra muscle, as muscle weighs more than fat.

Sample meal plan for high activity

Breakfast
Lunch
Dinner

Day 1

• 4-6 wheat biscuits
• 1 glass of reduced-fat milk
• 2-4 pieces of toast with margarine and spread
• 1 glass of orange juice

• 2 sandwiches - filled with salad and tuna
• banana smoothie - made with reduced-fat milk and yoghurt

• minestrone soup
• spaghetti - vegetable-based sauce with lean mince meat

Day 2

• omelette - with ham, reduced-fat cheese
• 2-4 slices of toast
• 1 glass of orange juice

• 2 banana sandwiches with honey or sultanas
• smoothie

• risotto rice - chicken, spinach and red capsicum, topped with reduced-fat cheese
• fruit salad

Day 3

• baked beans
• 4 slices of toast with margarine
• 1 glass orange juice

• 2 toasted sandwiches with reduced-fat cheese and tomato
• 200g reduced-fat yoghurt

• roast chicken (eat skinless, lean breast)
• roast vegetables (sweet potato, corn, peas, carrots)
• 2 slices bread
• reduced-fat custard and bananas

Snacks

Include 6-8 glasses of water a day.
Choose 1-2 snacks a day if hungry from the following options:

• raisin toast
• fruit
• coffee scroll
• cereal
• smoothie
• crumpets
• reduced-fat yoghurt
• muesli bars
• jacket potato
• minestrone soup
• rice cakes with honey.

Acknowledgement

• This information has been sourced from The Department of Human Services.