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A balanced, healthy diet? A Healthy Diet Is an important part Of an active, healthy lifestyle Growth Energy Tissue replacement and repair A balanced diet provides us with all the nutrients we need, but not too much of things such as salt, sugars or fats which could lead to ill health. Carbohydrates Water Protein 7 Essential components Fibre Fats Vitamins Minerals Carbohydrates • Are made up of the chemical elements of carbon, hydrogen and oxygen. • They are high in glucose and are primarily involved in energy production. • Stored in the body (muscles, liver and kidneys) as glycogen in limited but readily available amounts which need to be replenished Complex or carbs? Release energy slowly over a long period of time simple Include glucose and fructose and provide a quick energy fix Carbohydrates • Are essential to the nervous system and determine fat metabolism. • Are very important to the athlete, especially in high intensity exercise, (about 60% of an athletes diet should be carbohydrate). • When exercise takes place, glycogen is broken down to glucose which supplies muscles with energy. • When glycogen stores are depleted, there is less energy available and the performer will become tired. • Carbo loading. Daily calorie intake • The UK Dept of Health EAR (estimated average requirement) is 1,940 calories per day for women and 2,550 for men (313 grams of carbohydrate). • Leading up to Beijing Michael Phelps was reported to be eating about 12,000 calories a day. Fats • Supplies approx 70% of our energy requirements • Is the body’s preferred energy source • A major source of energy for athletes performing lowintensity endurance exercise Fats • Fats (or lipids) are made up of carbon, hydrogen and oxygen, but in different proportions to carbohydrates. • Two types: triglycerides – stored in the form of body fat fatty acids – used mainly as fuel for energy production (can be either saturated or unsaturated) Saturated fats • Solid form at room temperature (eg lard) • Primarily from animal sources • Meat products, dairy products, cakes, confectionery Unsaturated fats • Liquid form eg in vegetable (olive) oil • Mainly from plant sources eg nuts • Also from oily fish Fats • When muscle cells are readily supplied with oxygen, fat is the usual and preferred fuel for energy production • This is because the body is trying to save the limited stores of glycogen for high-intensity exercise and therefore delays the onset of fatigue • But the body cannot solely use fat for energy and so the muscles are fuelled by a combination of fat and glycogen • Fat is also very important to protect vital organs and is crucial for cell production and the control of heat loss. Fats • Fat consumption should be carefully monitored and can cause obesity • It is generally accepted that a maximum of 3% of total calories consumed should be from fatty foods Protein Meat, fish and poultry – complete proteins Vegetables, nuts and grains – incomplete proteins (lacking in essential amino acids Protein • Composed of carbon, hydrogen, oxygen and nitrogen and some contain minerals such as zinc. • Proteins are a potential source of energy, but are not used if fats and carbohydrates are in plentiful supply. • Important for repair and growth of new tissue. • Also important in development of hormones, enzymes and haemoglobin in the blood. • Should account for approx. 15% of total calorie intake. Protein • Excessive protein intake can lead to kidney damage. • Protein breaks down more readily during and after exercise. • The amount of protein broken down depends on how long and how hard you exercise. • Increased protein intake may be important during the early stages of training to support increases in muscle mass and myoglobin Minerals • Are non-caloric and are inorganic elements essential for our health, e.g. building tissue • Minerals can be lost through sweating – implications for exercise – minerals should be replaced quickly to ensure good health Macro minerals • • • • E.g. calcium, potassium and sodium (regulates body fluids) These are needed in relatively large amounts (although beware too much salt, which can contribute to high blood pressure, heart and kidney disease) Calcium is essential for healthy bones and teeth. A deficiency increases the likelihood of osteoporosis and bone fractures Calcium is found in milk and dairy products, green vegetables and nuts. It needs vitamin D (found in sunlight) to be absorbed. Trace elements • E.g. iron, zinc and manganese. • These are needed in small amounts. • Iron is an essential component of haemoglobin which carries O2 in the blood. • Iron deficiency anaemia can impair performance in endurance events. However, too much can be dangerous. • Iron can be found in meat (especially red meat and offal), fish, dairy produce and vegetables. Vitamins • • • • • • • • Non caloric chemical compounds needed by the body in small quantities. Fat soluble (A,D,E) Water soluble (B,C) Vital in the production of energy, the functioning of our metabolism and the prevention of disease. Vitamins found in fresh fruit and vegetables. Extremely large doses can be dangerous Little evidence to support supplementary vitamin pills enhancing performance Most excess vitamins are excreted via urine Fibre • • • • • • No calories, vitamins or minerals in fibre and not digested when we eat it. 2 types, soluble and insoluble, found in the cell walls of plants (found in wholegrains, fruit & veg) Essential for healthy bowel function Helps to retain water (thus increases the bulk of waste matter, makes it softer and increases speed and ease with which it passes through the bowel). Reduces risk of constipation, haemorrhoids and cancer of the colon or large bowel Deficient in many peoples diets. Aim for an intake of around 18gm a day. Water • Essential for good health. • Makes up more than 70% of the body • Carries nutrients and helps remove unabsorbed food & waste products • Essential for body’s chemical reactions • Essential part of blood • Esssential in temperature regulation (sweat & urine) • Should drink approx 2 litres a day. Dehydration and sport • Important to take fluids during prolonged exercise. • Dehydrated individuals become intolerant to exercise and heat stress • The CV system becomes inefficient • Inability to provide adequate blood flow to the skin > heat exhaustion Composition of a healthy diet Carbohydrate – 50% Fat – 30-35% Protein – 15-20% The National Institute for Health and Clinical Excellence (NICE) recommends: • Base your meals on starchy foods such as potatoes, bread, rice (wholegrain where possible) and pasta. • Eat plenty of fibre rich foods such as oats, beans, peas, lentils, grains, seeds, fruit and vegetables. • Eat at least 5 portions of a variety of fruit and vegetables a day in place of foods high in fat and calories. • Avoid foods containing a lot of fat, sugar and salt such as fried food, (‘takeaway foods’), sweetened drinks, sweets and chocolate. • Eat breakfast • Regulate portion sizes • Avoid too much alcohol Alcohol • Is a concentrated source of energy but is not available during exercise for our working muscles • The Health Development Agency and NICE recommend no more than: 3-4 units per day for males, 2-3 units per day for females • Avoid ‘binge drinking’. Spread your alcohol consumption and leave some alcohol free days • One unit = half pint of beer (30 calories), standard glass of wine(90 calories), single measure spirits (50 calories) Basic considerations • Food is meant to be enjoyed • You don’t have to give up all of your unhealthy ‘bad’ foods • The right balance is essential for health and fitness Other factors to keep in mind which affect food choices • • • • • Culture, morals, ethics Family influences Peer group influences Lifestyle finance