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Nutrition, Diet and Dietary Habits •The foods you body needs •A Balanced Diet •Food, Body and Energy •The Calories •Body Composition and Fitness •Diet and Exercise •How to plan your Balanced Diet •Obesity and Anorexia

•Nutrition can be defined as what we put in our mouths as it is used as fuel for the body to carry out essential functions: breathing, moving, growing, speaking, thinking. •Good nutrition is important throughout the lifespan, but it is vital for teenagers. The teenage years are when people grow the most, build bone density, and start to adopt lifelong habits. image 2

•Diet is the sum of food consumed by a person. With the word diet, it is often implied the use of specific intake of nutrition for health or weight-mananement reasons. •Dietary habits are the habitual decisions an individual or culture makes when choosing what foods to eat. •Calorie, kilogram calorie, dietary calorie or food calorie (symbol: Cal) approximates the energy needed to increase

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the temperature of 1 Kilogram of water by 1°C. This is exactly 1000 small calories or about 4.2 kilojoules.

The foods your body needs Your body needs four kinds of nutrients for energy, to grow, and to repair itself. It also needs water and fibre. •Carbohydrates •Fats •Proteins •Vitamins and Minerals •Water and Fibre

Carbohydrates •

These are our main source of energy.

They can be: – simple carbohydrates - sugary foods like cakes and biscuits, etc.

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– complex carbohydrates - starchy foods like potatoes, rice and pasta - we should eat more of these than simple carbs. image 5

Complex carbohydrates are broken down into simple carbs. (such as glucose/fructose etc) in the stomach. Some is used for energy straight away and some is stored in the liver and muscles as glycogen. Carbohydrates should make up a total of 55% of your daily diet.

Proteins Proteins are used to help us grow and repair tissues . Proteins are found in animal products such as meat, fish, milk and eggs and they are also found in beans and lentils.

Proteins are made from amino

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acids, and these can be: – essential, meaning we can't make them in the body so you must eat them in your diet . – non-essential - meaning your body can make them . Proteins should make up 15% of your daily diet.

Fats Fats are a source of energy and also provide warmth for our bodies and protection for our vital organs . There are three types of fat:

– Saturated Fatty Acids - Which are mainly found in animal fats and are usually hard at room temperature e.g. Butter – Monosaturated Fatty Acids - These are usually liquid at room temperature such as oils . – Polyunsaturated Fatty Acids - These are the best type of fat for you and are found in oily fish and some oils . image 8

Fats should make up 30% of your daily diet . We also need the following nutrients in small amounts, to stay healthy:

•Vitamins Vitamins are needed for chemical reactions and also to help our bones, skin and teeth to grow .They can be either fat soluble or water soluble. •

Fat soluble vitamins can be stored in the body and include: - Vitamin A for growth and seeing in the dark! Found in vegetables, liver and eggs. - Vitamin D for strong bones, found in milk, fish and eggs .

Water soluble vitamins cannot be stored in the body so we need to eat these in our diet .

They include Vitamin C which you need for healthy

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skin, gums. This is found in fruit and vegetables .

•Minerals We need them for healthy bones and teeth, as well as the growth of other tissues . Minerals include things like: - Calcium for strong bones and teeth as well as muscle contraction. This is found in dairy products and vegetables . - Iron for haemoglobin in red blood cells. You can get iron from liver, beans and other green vegetables .

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They are used in many chemical reactions in the body too .

•Water Water doesn't count as a nutrient, but its something your image 11 body needs . You need it in chemical reaction and for when you sweat to cool your body down . If you don't drink enough you can become dehydrated. This can affect your performance If you drink too much you just produce extra urine to get rid of it! image 12

•Fibre Fibre isn't really a nutrient either, but you definitely need it in your diet . It keeps your digestive system working properly. image 13

You can find it in fruit and vegetables

A Balanced Diet

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People are always talking about a balanced diet, but what does this actually mean? A balanced diet contains all the nutrients you need, in the right amounts to keep you healthy. The best way to make sure you get this is by eating a varied diet. One that contains the following four food groups: •

* Meat and fish

* Dairy products (Milk)

* Fruit and vegetables

* Bread, cereals, potatoes, nuts, pulses etc.

Doing this will ensure you get a mixture of Carbohydrates, Proteins and Fats.

Healthy eating means a balanced diet, which


-Has the right mix of nutrients, fibre and water. 55%

-Matches your energy needs.

The right mix image 15

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Food, Body and Energy How much energy do foods give? •

1 gram of fat 38.9 kj (9 C)of energy

1 gram of protein 18.2 kj (4C)

1 gram of carbohydrates 17.1 kj (4C) Fats gives most energy. So it is very easy to eat more fats than you need for

energy. When this happens you put on weight.

1 gram of alcohol 7 kilocalories

How much energy do you need? Total energy needed = Basal metabolic rate (BMR), the energy you need just to be alive, awake and comfortably warm + Working energy, the extra you need to move, and digest food It is measured in kilojoules (kj) or Kilocalories (C)

1 kilocalorie = 4.18 kilojoules

Energy daily needed •BMR -Male = 1 C/h/kg. -Female = 0’9 C/h/kg. •Physical Activity -Rest = 1 x hours x BMR -Light = 1’5 x hours x BMR -Medium = 2’5 x hours x BMR -Intense = 5 x hours x BMR -Extreme = 7 x hours x BMR •

Food Thermogenesis = 8% of total caloric spending

The energy balance •Energy In

•Energy Out

Food is energy you take in

-Watching tv - School -Around the house -Football -Eating -Sleeping

•If energy in = energy out, you won’t put on weight. •If energy in is more than energy out, you’ll put on weight. The extra food is stored as body fat. Even carbohydrates and proteins are changed to fat. Over time you could become

obese. •If energy in is less than energy out, you’ll lose weight. Your body will use stored body fat for energy. But if this goes too far, you may become anorexic.

The Calories How to work out the caloric spending? •Female 55 kg weight. •Sleeping (9 hrs) + Watching tv (1 hr.) = Rest •At School (5’5 hrs.) + Breakfast, meal, dinner (1h.) + homework (1’5 hrs.) + other (1h.) = Light Activity •Walking: to school, shopping, (1h.) + housework (1h.) + other (1h.) = Moderate Activity •Basket training (2 hrs.) = Intense Activity •BMR 0’9kCal/kg./h= 0’9x55kgx24hrs.=1188kCalories •Physical Activity •- Rest: 10 hrs.=10x0’9x55= 495 kCal. •- Light: 9 hrs.= 9x1’5x55= 742’5 kCal. •- Moderate: 3 hrs.= 3x2’5x55= 412’5 KCal. •- Intense: 2 hrs.= 2x5x55= 550 KCal. •Total: 24 hrs.= 2.200KCal. •Thermogenesis food •2.200 + (2.200x8%)= 2.376 KCal. Total Daily Caloric Spending

How many calories do people need each day? Most adults need about 2,000 calories a day. The exact number depends on a person's sex, age, and physical activity level, as shown in the table.Eating or drinking more calories than the body uses causes weight gain - which can lead to obesity, diabetes, and heart disease. •Age: you need more energy than a child or an elderly person. •Gender (sex): Males usually need more energy than females of the same age. •Lifestyle: The more active you are, the more energy you need. A top athlete needs more than an office worker.

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Caloric Spending

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Caloric Spending and Physical Activity

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How to lose weight A healthy balance diet


(a little less than usual)

Regular exercise (more than usual)

How exercise affects your weight •Regular exercise increases your basal metabolic rate. You burn up stored fat faster even when you’re resting. •It also reduces the appetite. •Your muscles grow with exercise. They weigh more than fat but take up less space. So you won’t lose much weight at the start but you’ll look slimmer.

Body Composition and Fitness You could be just the right weight, but unfit because you have lots of fat and small weak muscles. So body composition gives a better idea of fitness. It states what percentage of your body weight is fat. Askinfold test is used to estimate it. The result

% fat for a male

% fat for a female





Over 15%

Over 20%


Over 20%

Over 30%

Diet and Sport •As well as thinking about having a balanced diet and getting all of the nutrients your body needs on a daily basis, athletes also have to think about what foods are going to benefit their sporting performance and when they should eat to fit around training and competitions.

•Athletes involved in different sports will have very different diets. For example, a weight lifter will eat a diet high in protein to help their muscles grow. An endurance athlete will have a diet high in carbohydrates to store their muscles with glycogen for energy. •When building up to a competition, some athletes will also use a technique called carboloading, where they eat a lot of carbohydrate rich foods in the run up to the event. This ensures their muscles and liver are stocked up with glycogen so they have plenty of energy. •During an activity you shouldn't eat anything as your digestive system may not be able to cope as the blood is being diverted to your working muscles, not your stomach! You should always make sure you keep drinking throughout exercise though, to replace the fluid you are loosing through sweat and breathing out more water vapor. •It is important to eat following exercise to replenish your energy stores. Don't eat straight away though, give your body and hour or two to recover. In this time you should continue to take on fluid to prevent dehydration.

How to Plan a Balanced Diet for Teenagers 1.Add vegetables to your grocery list. The recommendations are 2 to 3 cups a day for teenagers. One serving of green leafy vegetables is 2 cups, and for uncooked vegetables, 1 cup. 2.Add fruits to your grocery list. Aim for your teen to consume 1 to 2 cups a day. Try adding fresh fruit to cereal in the morning, an apple for snack, and a fruit and yogurt parfait for dessert. 3.Add whole grains to your shopping list. Whole wheat bread, pasta and cereal are great ways to meet the 3-oz. recommendations for the day. A slice of bread or 1 cup of cereal is counted as 1 oz. 4.Add milk and dairy products to your list; they are known for building strong bones but also contain potassium, vitamin D and protein. The recommendations are 3 cups per day for teens. One cup of milk or yogurt or 1 1/2 oz. of cheese counts as one serving.

5. Add good sources of protein to your list, such as lean chicken, lean turkey lunch meat, eggs, fish, tofu or beans. The recommend is 5 to 6 oz. a day. 6.Purchase olive oil for stir-frying vegetables or peanut butter to put on apples. The recommendations suggest no more than 6 tsp. of added fats/oils per day for this age group.

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Obesity & Anorexia •

Obesity is a severe overweight

condition of the body • •

little fat.

It is usually caused by eating too

It’s caused by hards dieting.


Without food, your body starts to use

It puts a strain on the heart, muscles, bones and ligaments.

Anorexia means you have far too

up stored fat for energy. •

When this runs out it will use proteins

Exercise gets difficult or even

from body tissues. Organs stop


working. You die.

Obesity can lead to joint and back injuries, heart attacks, strokes and other problems.

Anorexia leaves you weak and tired, with a weak immune system.

Bibliography •McLatchie G. (2003) Understanding Sports & Exercise Medicine. Family Doctors Pubications • • •

Images image 1: image 2: image 3: image 15: image 5: image 4: image 6: image 7: et-hd-64.jpg image 8: image 9: image 10: image 11: image13: image 14: image 12: image 16: s400/the+food+pyramid.gif image 20: image 20: image 17: •image 18: •image 19:

•Note: This material was prepared by Victor E. Rodríguez Rodríguez for the Bilingual Section of Physical Education (English) of the IES. A Guía, Vigo. I used images from of and sites, and in all the images I have added their reference. In this work, I have also included portions of the text of the different sites, which are reflected in the bibliography at the end of the text . This material was elaborated for exclusively educational purposes and non-commercial uses.

•Nota: Este material foi elaborado por Víctor E. Rodríguez Rodríguez para a Sección Bilingüe de Educación Física (inglés) do IES. A Guía de Vigo. Utiliceí imáxenes de lugares web ( e ) e en todas elas engadín a súa referencia. Neste traballo, tamén incluín porcións de texto de diferentes páxinas web, reflectidas na bibliografía ao final do texto. Este material foi elaborado con fins exclusivamente didácticos e sen uso comercial.

Nutrition Notes  

Nutrition Notes

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