Nutrition Basics. Australian Institute of Fitness 1 / 10

Transcription

1 Nutrition Basics Australian Institute of Fitness 1 / 10

2 INTRODUCTION Understanding nutrition is fundamental to good health, performance, weight loss and weight management. Fitness professionals play the role of advising clients on healthy eating and providing tips to assist clients achieve their goals. Eating a variety of healthy foods is the key to a well-balanced diet and good nutrition. It keeps our bodies working well and helps prevent diseases such as diabetes, cancer and cardiovascular disease. A good balance between exercise and food intake is important to maintain a healthy body weight. We introduce you to the basics of nutrition by looking at the key macronutrients, how to balance these macronutrients and dietary guidelines for good health. By the time you are ready to train clients, you should be able to educate clients about better food choices. Knowing the approximate energy value of common foods e.g. a meat pie has 1880 kj (450 calories) and 27g of fat which is about half the recommended daily fat intake hence not a good food choice. It is also useful to know the approximate macronutrient content of common foods e.g. a 100g chicken breast has about 25g of protein. The good news is that we have plenty of resources to assist us with the 'numbers' - try or buy a calorie and fat counter which are available from most bookshops. Australian Institute of Fitness 2 / 10

3 ENERGY IN Our body breaks down the carbohydrates, fats, proteins and alcohol from the food we eat and converts them into mechanical energy for synthesis (making stuff), muscular activity (doing stuff), metabolic processes, and electrical energy for nerve impulse transmission (sending messages within the body). Carbohydrates, fats, proteins and alcohol are known as substrates or macronutrients and hold energy in their molecular bonds. When food is broken down and metabolized, these bonds are broken and energy is released (ATP). Did you know that a calorie is the measurement of energy produced by a substrate/macronutrient and is measured as heat? It is the amount of heat required to raise the temperature of 1 gram of water to 1 degree Celcius. Below is the amount of energy that each macronutrient yield: 1 gram of carbohydrate yields 4.2 calories = 17 kilojoules 1 gram of fat yields 9 calories = 37 kilojoules 1 gram of protein yields 4 calories = 16 kilojoules 1 gram of alcohol yields 7 calories = 29 kilojoules There areâ four macronutrients and even though alcohol is recommended in moderation, it is still a macronutrient because it yields energy. Australian Institute of Fitness 3 / 10

4 Carbohydrates Carbohydrates are found in foods such as breads, cereal, rice, pasta, fruit, vegetables, lollies, sugar, soft drink and fruit juice. The primary role of dietary carbohydrate is the provision of glucose energy to cells and it is the body s preferred source of energy during exercise. Glycemic Index The latest and most accurate method of classifying carbohydrates is called the Glycaemic Index (Gl). The GI is used to classify carbohydrates according to their effect on blood glucose, specifically how long it takes for the glucose from a food to be absorbed into the blood. Each food is compared to glucose which has a glycemic index of 100. The faster blood sugar rises when this food is eaten, the higher the GI. The slower the glucose absorption, the lower the GI. A high glycemic index value is >70. A medium value is A low value is <55. It is believed that by eating food that have a low GI, we get more even blood glucose levels throughout the day which provides sustained energy. Lower GI is best for diabetes and fat loss due to less insulin being required (insulin also stores fat). High GI is best for athletes to store glycogen post-exercise. Australian Institute of Fitness 4 / 10

5 Fat Different kinds of fats have different effects on our health; some are highly recommended and others need to be reduced and in some cases even eliminated altogether from our diet. Saturated fat (bad fat) is found in animal products such as fatty meats, bacon, kidney, liver, egg yolks, whole-milk products such as butter, full cream milk and cheese. We should avoid saturated fat as our liver manufactures blood cholesterol from saturated fat, thus the more we eat, the more cholesterol it makes. Excessive blood cholesterol can lead to blocked arteries, and has been linked to coronary heart disease and high blood pressure. Polyunsaturated fat (good fat) is usually liquid at room temperature and sources include vegetable oils such as canola, peanut, safflower, sesame, soy, corn and sunflower-seed oils, and fish such as tuna, snapper and salmon. Monounsaturated fat (good fat) is high in foods such as olive oil, olives, avocado, almonds, cashews, hazelnuts, walnuts, and seeds such as sesame seed and pumpkin seeds. Fat is essential for growth and development, repair and body functions. Fats are a source of the essential fatty acids which maintain the functioning of cell membranes and are a great source of concentrated and sustained energy for the body. Fats also provide cushioning and insulation for the body and are involved in brain function, nerve transmission and hormonal production. In addition, they are responsible for carrying fat soluble vitamins such as vitamins A, D, E and K, and the good fats help prevent heart disease. Download the questionnaire and complete it for yourself then practice completing it on any willing friends or family members. You must be honest and only circle one answer/number. Add up the numbers, write the total in the box provided and compare the score to the ratings below = Low fat intake = moderate fat intake 40+ = high fat intake Australian Institute of Fitness 5 / 10

6 Protein Proteins are found in both animal and plant food. Sources include meats, dairy, poultry, vegetables, nuts and breads. Proteins are necessary for growth and cell replacement, in fact, protein provides the building blocks for the body to build and repair tissue such as muscle, hair, nails and skin. Protein is also necessary for the production of enzymes, antibodies and certain hormones. Essentially, they have both functional and structural properties. Australian Institute of Fitness 6 / 10

7 Quiz - Energy In 1. How many calories/kilojoules does 1 gram of carbohydrate yield? 2. Which type of fat is found in animal products and shouldn t be consumed in excess as it increases the production of cholesterol? 3. What is the role of protein in our body? Hover your cursor over the questions to reveal the answers. Your Turn Supermarket Adventure Analyse the food labels for the following foods in the table below and work out the energy value of each macronutrient using the 100 gram value on the food label. Carbohydrates = 16 kj per gram Protein = 17 kj per gram Fat = 37 kj per gram; Alcohol = 27 kj per gram Download the table here. Australian Institute of Fitness 7 / 10

8 BALANCING THE MACRONUTRIENTS We all know that a balanced diet is essential for good health, exercise performance, recovery from exercise, and prevention of disease. Having a variety of foods also ensures we consume adequate nutrients. Below arethe acceptable macronutrient distribution ranges for ensuring a balanced diet. Carbohydrates = 45-60% Protein = 15-30% Good Fats = 20-30% Other tools that can assist in encouraging a balanced diet are food pyramids. Below is the most recently released Mediterranean Food Pyramid which was updated in 2008 to reflect the health benefits of plant food, fish and seafood, and the health, taste and cultural aspects of herbs and spices. It also includes the benefits of being physically active. For more information Australian Institute of Fitness 8 / 10

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10 Australian Dietary Guidelines The Australian Government releases and regularly updates dietary guidelines for adults, children and adolescents. This includes RDIs (recommended daily intakes) and NRVs (nutrient reference values) for macronutrients, vitamins and minerals. You can find these on the website The following dietary guidelines have been developed and published for all Australians: Prevent excess weight gain Enjoy a wide variety of nutritious foods Eat plenty of vegetables, legumes and fruits Eat plenty of cereals, preferably wholegrain Include lean meats, fish, poultry and/or alternatives Include milk, yoghurt, cheese and/or alternatives Drink plenty of water Limit saturated fats and moderate total fat intake Choose foods low in salt Limit your alcohol intake if you choose to drink Consume only moderate amounts of sugars and foods containing added sugars Care for your food; prepare and store it safely Encourage and support breastfeeding Eat low GI food Another great resource is the Australian Guide to Healthy Eating; visit the website In addition to published guidelines, we at the Institute believe in these five key points to looking and feeling fantastic. 1. Positive attitude get your head right 2. Drink more fluid 3. Eat more real food fruit, veggies, nuts and less junk food 4. Move more planned and unplanned 5. Get strong and supple Australian Institute of Fitness 10 / 10