y g o l iB o gy o l o e G DEMO
and
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DA CON
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AT DUC
3
a oca lebr te R z Cu men e e l u C ng S. omí a A. D arcí Mª G uiz R . B A.
12
M ON
THS LICEN CE
DIGITAL PROJECT
INCLUDED
GLO BAL
THINKERS
Indenxowledge of the course Basic k
The scientific method 1. 2. 3. 4.
................................................................................................... 10
The scientific method Research in the laboratory Research in a natural environment Finding information
Glossary Research Project ............................................................................. 26 CHALLENGES THAT LEAVE THEIR MARK
Superchefs ........................................................................................ 30
1 The organisation of the human body • 1. 2. 3. 4. 5.
.................................... 32
Ada Yonath. Curious by nature Levels of organisation The human cell Cell differentiation Human tissues Organs and systems
Understand, reflect on your learning and test yourself Glossary
2 Nutrition and food • 1. 2. 3. 4. 5. 6. 7.
.....................................................................................................
50
Louis Pasteur. A chemist, bacteria and a theory Nutrition in humans Nutrients Energy supply Eating Dietary recommendations Food and sustainability Diet and health
Understand, reflect on your learning and test yourself Glossary
3 Systems of the nutrition function • 1. 2. 3. 4. 5. 6. 7. 8.
...............................................
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Lucy Wills. A fighter for anaemia The digestive system Digestion The respiratory system The circulatory system Blood flow The lymphatic system The excretory system Health and the nutrition function
Understand, reflect on your learning and test yourself Glossary
Portfolio ............................................................................................. 94
CHALLENGES THAT LEAVE THEIR MARK
CHALLENGES THAT LEAVE THEIR MARK
Help! Emergency! ........................................................................... 96
Living in a volcano ........................................................................ 176
4 The interaction function
7 Dynamic Earth
• 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.
................................................................................
98
Rita Levi-Montalcini. A pioneering neurologist The interaction function in humans Perception: the senses The sense organs and health Nervous coordination Health of the nervous system Endocrine coordination Health of the endocrine system Drugs and drug addiction Executing responses: the locomotor system Response execution and health
.....................................................................................................................
178
• Alfred Wegener. An explorer with a big theory 1. The Earth’s surface and its dynamics 2. The Earth’s internal energy and endogenous processes 3. Magmatism and volcanoes 4. Tectonic forces 5. Geological risk Understand, reflect on your learning and test yourself Glossary
Understand, reflect on your learning and test yourself Glossary
5 Reproduction
................................................................................................................
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• Marie-Anne Victoire Gillain Boivin. A wise gynaecologist 1. Human reproduction 2. The reproductive system 3. Human gametes 4. The ovarian and uterine cycles 5. Fertilisation, pregnancy and birth 6. Birth control and reproductive health Understand, reflect on your learning and test yourself Glossary
8 Landform modelling • 1. 2. 3. 4. 5. 6. 7. 8. 9.
.............................................................................................
194
Marjorie Sweeting. The great karst explorer Landform modelling Exogenous geological processes The geological action of wild waters and torrentes The geological action of rivers The geological action of groundwater The geological action of glaciers The geological action of wind The geological action of the sea The geological action of living beings
Understand, reflect on your learning and test yourself Glossary Exploring our geological heritage .................................... 218
Portfolio ........................................................................................... 222
6 A healthy life • 1. 2. 3. 4. 5. 6. 7.
....................................................................................................................... 152
James McCune Smith. The hope of his people Health and illness Types of illnesses Transmission of infectious diseases The immune system Preventing and curing illnesses Transplants and donation First aid
Understand, reflect on your learning and test yourself Glossary
Portfolio ............................................................................................ 174
2
D O O F D N A N O I T NUTRI
1 Answer
LOUIS PASTEUR
the
questions,
giving
supporting
evidence. a) What was Louis very good at when he was a child? b) Did Louis believe in spontaneous generation? c) What was Louis’ ‘germ theory’ about? d) Could you explain briefly the process of pasteurization?
A chemist, bacteria and a theory My name is Louis Pasteur, and I was born in Dole, France, in 1822. When I was at school, Science was my worst subject. It’s quite funny that I am now one of the most famous scientists of all time. As a child I was very good at drawing and painting, so my teachers told me to focus on that. I wanted to become an art teacher, but my father wasn’t very impressed about that. He wanted me to study other subjects as well, so I did a degree in Mathematics, graduating from the University of Dijon in 1842. With very mediocre marks in physics and chemistry, I have to add. Then, after a lot of effort, I managed to earn a doctorate in Physics and Chemistry in 1847.
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then, people believed that simple life forms, (such as flies or worms) could develop from inert materials such as broth or dirt. I did a simple experiment to verify this: I exposed a flask with meat broth to the air but covered it with a filter so that no living things could get into the broth. As I expected, neither flies norworms developed under those conditions.
After that, I got a job as a physics teacher at the Lycée de Dijon, and then as a chemistry teacher at the University of Strasbourg. I was finally able to spend some time investigating things that interested me. And it wasn’t a waste of time, I can tell you that!
Another of my great achievements was ‘germ theory’. I proved that infectious diseases are caused by microorganisms called bacteria and that these diseases are transmitted from person to person. Then I had an idea: killing microorganisms in food and drink by heating them to a very high temperature. This process is called pasteurization, naturally. After that, I made an important discovery: using a weak form of germs could make a person immune to a disease. Using this research, I developed vaccines for two terrible diseases: cholera and rabies.
For example, I proved once and for all that there was no such thing as spontaneous generation in 1864. Until
Even if I say so myself, I did quite well for a mediocre student. Am I right?
GES THAT
CHALLEN
LANGUAGE BANK SPEAKING
1 You are going to debate ideas related to food and nutrition. Step 1: Below are three statements. You will be split into 6 groups to be for and against each one. Statement 1: Advice in magazines helps you to make healthy diet choices. Statement 2: It is useful to label food as good or bad. Statement 3: Everyone should eat a Mediterranean diet. Step 2: Plan your arguments. You should try and prepare counterarguments to other team’s claims. Step 3: Debate with the other team for 5 minutes. Include an opening and closing speech, as well as a time of open debate. Step 4: The rest of the class will vote for the winning team. WRITING
Agony aunt: advice letters
2 An agony aunt is a person who responds to anonymous letters from people who have problems. They give advice to help resolve or improve the situation.
EIR LEAVE TH
MARK
LEARNING SEQUENCE MAKE YOUR OWN ‘NUTRI-SCORE’ 3.1 In this step, you’ll analyse the food students bring to class. First of all, find nutritional information about it. 3.2 Analyse the food labels and note down whether each item is healthy or unhealthy. 3.3 Use the data you have collected to make your own ‘Nutri-score’. Research what this system is and what it is used for. 3.4 Use your ‘Nutri-score’ to rate your food items. Draw a diagram to represent the eating habits of your class at the moment. SUPERCHEFS: DESIGNING A HEALTHY DIET 4.1 You’re going to design a healthy breaktime eating plan. First of all, list the criteria that determine what a healthy eating plan is. 4.2 Choose healthy foods that you can easily bring to school. 4.3 Design five healthy breaktime snacks using the foods you have chosen. 4.4 Analyse how healthy your snacks are. Check that they meet all the criteria on your list. Make any changes, if necessary, so that they meet all the criteria of the healthy eating plan.
Step 1: Write a letter to an agony aunt asking for advice on an invented or real issue relating to nutrition and diet. Step 2: Swap your letter with a classmate and be the agony Aunt now. Write a reply giving advice.
+ for guidelines, go to anayaeducacion.es 51
1
NUTRITION IN HUMANS
1.1 The nutrition function The cells in our body cannot obtain nutrients themselves and need organs and systems to provide them. Specialised nutrition organs perform the following processes:
• They obtain nutrients from
Nutrition is the group of processes that allow humans to obtain the matter and energy they need to build and maintain their structures and do activities.
food, and oxygen from air.
• They transport nutrients and oxygen to cells. • They perform cellular respiration, which takes place in the mitochondria of cells.
Understand, think, search... 1 What is nutrition? 2 What systems are needed for nutrients and oxygen to reach the cells?
3 Which systems are involved in removing waste products and carbon dioxide? Where do these substances come from?
• They remove cell waste and carbon dioxide, which must be transported from the cells to the organs responsible for expelling them.
1.2 Systems of nutrition The nutrition function is performed by the digestive, respiratory, circulatory and excretory systems, and the lymphatic system.
Digestive system The digestive system transforms foods into simpler substances (nutrients) and ensures they pass into the blood. It uses the digestive and absorption processes to do this.
Circulatory system The circulatory system transports nutrients and oxygen through the blood to the cells. It also removes waste and takes it to the excretory organs.
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Respiratory system The respiratory system is responsible for gas exchange. It takes oxygen from the air, passes it to the blood and removes carbon dioxide, which is then expelled from the body.
Lymphatic system
Excretory system
The lymphatic system works with the circulatory system to transport substances.
The excretory system removes waste products from the blood. These products are generated by cell activity and then expelled. It is formed by the excretory organs.
UNIT
2
NUTRIENTS
2
Humans get nutrients through heterotrophic nutrition. This means that they take organic matter in the form of food and obtain the nutrients they need from them to survive.
Classify nutrients
Nutrients are compounds in food that the body needs to function correctly. The body obtains them through the digestion process.
DIFFERENT WAYS OF CLASSIFYING NUTRIENTS According to their function Nutrients with energy-producing functions
Nutrients with body-regulating functions
Nutrients can be classified in different ways. For example, according to their function, according to the amount of food we need to eat or according to their chemical composition.
2.1 Types of nutrients according to their function
Nutrients with body-building functions
• Nutrients with body-building functions. Some nutrients, like proteins, some lipids, calcium and water, supply the body with materials to build and repair the body’s structures and tissues.
According to the amount we need to eat Macronutrients
Micronutrients
According to their composition Carbohydrates
Water
• Nutrients
with energy-producing functions. Carbohydrates and lipids are the main nutrients that provide our body with the energy it needs to perform the vital functions. Proteins can also provide energy, but they have a mainly structural function.
• Nutrients Minerals
Proteins
Fibre Vitamins
Lipids
Look at the diagram and read the text about different ways of classifying nutrients. Now fill in the following table in your notebook:
Proteins
Body-building and, sometimes, Macronutrients energy-producing functions
Lipids
?
?
Water
?
?
Vitamins
?
?
Minerals
?
?
Carbohydrates
?
?
Fibre
?
?
with body-regulating functions. These are nutrients that regulate the metabolic processes of our body. These are mainly vitamins and minerals, but water and fibre also perform this function in the body.
2.2 Types of nutrients according to the amount we need to eat • Micronutrients. The body needs them in very small amounts. These nutrients are vitamins and minerals.
• Macronutrients. The body needs them in larger amounts. These are proteins, lipids, carbohydrates and water. Technology
Create
How do we know we are eating the correct amount of nutrients? Research apps that are used to track food consumption and see if they register the nutrients gained. Now its your turn to think about the features you would want to see in an app about food and nutrition.
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2
NUTRIENTS
2.3 Types of nutrients according to their composition Inorganic nutrients
• Water is the main component of humans. It makes up 55 to 70 %
Essential nutrients are the nutrients that our body cannot synthesise enough of, but are essential for our growth and development. Therefore, they must be in the food that we eat.
of body mass. It is an essential nutrient so it is important to ingest it either directly or through food. It has many functions: it acts as a solvent for nutrients, which allows substances to be transported around the body and facilitates chemical reactions in the cells; it has body-building functions; it helps maintain body temperature, etc.
• Minerals. The most important minerals are: calcium, phosphorus, iron, iodine, fluoride, sodium, chlorine, potassium, sulphur, magnesium, manganese, copper, cobalt, zinc, chromium, molybdenum and selenium. They have body-regulating functions: for example, calcium regulates muscle contractions and iron regulates the transportation of oxygen to the cells. They also have body-building functions, for example, phosphate and calcium in bones.
Organic nutrients
• Carbohydrates. The main function of carbohydrates is to provide energy. The simplest carbohydrates are sugars like glucose, fructose and sucrose. The most complex, also called polysaccharides, are formed by several hundred simple sugars joined together in long chains. They can be branched or linear. There are two important types. The first are digestible polysaccharides, which include digestible starch and glycogen. The second are non-digestible polysaccharides and these can only be partially used. They make up dietary fibre, and include resistant starch, celluloses, hemicelluloses and pectins.
• Dietary fibre. Fibre was traditionally included in the carbohydrates Understand, think, search... 1 Make a table linking nutrients to their functions.
2
Look at the resource ‘Vitamins’ in your resource bank at anayaeducacion.es and answer: a) What is the difference between hydrosoluble and liposoluble vitamins? b) What are the functions vitamin C and vitamin A?
3
54
of
Write around. Make one list of the biomolecules that make up the human body and another list of the nutrients. Compare both lists and discuss as a class whether they are related to the famous saying ‘you are what you eat’.
group because 90 % of the compounds that make up fibre are polysaccharides. However, other compounds that are considered fibre, like lignin, do not have this chemical structure. Fibre is essential in regulating the digestive functions. In particular, it regulates the movement of food through the intestinal tract and supports nutrient absorption.
• Lipids. Different lipids have different chemical compositions and fulfil several functions. For example, fats provide energy; cholesterol or phospholipids form part of cell membranes; and other lipids have regulating functions, like those that make up the sex hormones.
• Proteins. Proteins are macromolecules formed by simple molecules called amino acids. They have body-building functions because they are the second most common component in the body. They also have body-regulating functions such as enzymes that accelerate chemical reactions, defensive functions like antibodies, and transportation functions like haemoglobin.
• Vitamins. Vitamins have a wide variety of compositions. Even though we only need them in small amounts, they are essential in order for our body to function correctly. They are divided into water soluble vitamins (vitamin C and group B vitamins) and fat soluble vitamins (A, D, E and K).
UNIT
2
2.4 Food sources of nutrients Food sources of nutrients are foods that contain a larger amount of the nutrient compared to others. For example, potatoes are a carbohydrate-rich food, olive oil is a source of lipids, fish and meat are sources of proteins, and fruit and vegetables are a source of vitamins (see the table below). In addition to nutrients, foods also contain nonnutrients, which are substances that do not have nutritional value. As we will see later on, some of these substances can be harmful to the body.
Analyse foods Look at the composition of macronutrients in the following foods, given per 100 g of edible portion: Apple
Food sources Water
Apart from drinking it directly, water can be found in other drinks and also in foods such as fruits, vegetables and fish.
Minerals
They are present in almost all foods in varying amounts. For example: – iron is in liver, meat, fish, pulses, oily nuts and vegetables; – iodine is in iodised salt, fish, seafood, seaweed and vegetables, etc.
Carbohydrates
In fruit, honey, fruit juice and canned food, table sugar, grains, pulses, potatoes and root vegetables.
Lipids
Saturated fats are found in: butter, margarine, pastries, biscuits, offal, red meat, eggs and seafood. Unsaturated fats are found in: olive, sunflower, corn, soybean and grapeseed oils.
Proteins
Animal protein is found in: meat, fish, eggs, offal, milk and derivatives. Plant proteins are found in: pulses, soy beans and nuts.
Vitamins
Hydrosoluble vitamins are found in: meat, fish, liver, eggs, milk, nuts, grains, pulses and yeast. Liposoluble vitamins are found in: meat, liver, egg yolk, peanut, cocoa, vegetable oils, salmon, sardine, cod, chard and cruciferous vegetables like collard greens and cauliflower.
Fibre
Particularly in plant foods like vegetables, fruit, pulses, grains and cereal products, and nuts.
Water: 85.7 g Proteins: 0.3 g Lipids: 0 g Carbohydrates: 12 g Fibre: 2 g
Lean meat Water: 62.3 g Proteins: 21 g Lipids: 16.7 g Carbohydrates: 0 g Fibre: 0 g
Mixed nuts Water: 4.6 g Proteins: 22.9 g Lipids: 54.1 g Carbohydrates: 7.9 g Fibre: 7.5 g
Banana Water: 75.1 g Proteins: 1.2 g Lipids: 0.3 g Carbohydrates: 20 g Fibre: 3.4 g
Yoghurt Water: 87.9 g Proteins: 3.7 g Lipids: 2.7 g Carbohydrates: 4.4 g Fibre: 0 g
Chard Water: 87.5 g Proteins: 2 g Lipids: 0.4 g Carbohydrates: 4.5 g Fibre: 5.6 g
a) Order the food in this activity from the highest to the lowest amount of these macronutrients: water, proteins, lipids, carbohydrates and fibre. b)
Before I thought…, now I think Did you know, or were you surprised by, any of the information about the composition of foods in this activity? Apply this thinker’s key to help you. Learn how to do it by looking at the information in the resource bank anayaeducacion.es.
c) Look for information about the composition of some foods you ate today for breakfast and lunch. Order them the same way you did in activity a.
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3
ENERGY SUPPLY
As we have talked about before, some nutrients we get from foods are used as an energy source. Cells use the energy from nutrients for cell activities, such as transporting substances through the cell membrane, making cell components, moving, and so on.
The energy value of food is proportional to the amount of energy provided by the nutrient when the food is burnt in the presence of oxygen. In other words, during cellular respiration.
3.1 Cellular respiration Energy is obtained inside cells through cellular respiration. This process takes place in the mitochondria and requires oxygen. Cellular respiration consists of the following stages:
Stage one:
• Organic nutrients, mainly glucose, from food digestion, reach the cells.
Stage two:
• Once inside, the glucose enters the mitochondria, along with oxygen (O2) captured from the air in the lungs.
Stage three:
• In the mitochondria, the O2 combines with the glucose molecule.
The molecule breaks and releases the energy stored in its chemical bonds.
Stage four:
• The glucose molecule transforms into water (H2O), which stays inside the cell, and carbon dioxide (CO2), which is waste and is expelled from the cell. A simple way to show cellular respiration is by drawing a diagram:
Cellular respiration in the mitochondria Organic nutrients (glucose) from food digestion
Understand, think, search... 1 Where
in obtained?
the
cell
is
O2 (from lung respiration)
energy
2 Explain cellular respiration step by step.
3 What does the cell use the energy for?
4
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Find information to define metabolism, catabolism and anabolism. What type of metabolic process is cellular respiration?
H2O CO2
Energy
UNIT
3.2 The energy content of food
2
Calculating daily calorie needs
The majority of energy obtained from food comes from carbohydrates, but cells can also obtain energy from lipids and proteins. Cells only use lipids to obtain energy when there are no carbohydrates. Proteins are only used when there are no carbohydrates or lipids. These nutrients, which come from food, release their energy when they reach the cells.
The amount of energy released by foods is measured in kilocalories or kilojoules. A calorie is the amount of energy needed to raise the temperature of 1 gram of water by 1 °C. So, each gram of carbohydrate or protein gives 4 kilocalories, compared to 9 kilocalories given by one gram of lipids. Some nutrients, like micronutrients (vitamins and minerals), water and fibre, do not provide energy.
Kilocalorie and calorie
Kilojoule and joule
1 kcal = 1 000 cal
1 kjoule = 1 000 joules
We can calculate someone’s approximate basal metabolic rate (BMR) by using the Harris-Benedict equations: Men BMR = (10 × mass in kg) + (6.25 × height in cm) – (5 × age in years) + 5 Women BMR = (10 × mass in kg) + (6.25 × height in cm) – (5 × age in years) – 161 A correction factor is added to the result to take into account physical activity: – Sedentary lifestyle: Necessary daily calories = BMR × 1.2 – Regular and moderate exercise: Necessary daily calories = BMR × 1.5 – Frequent and intense exercise:
Conversions 1 cal = 4.186 joules
1 joule = 0.24 cal
Necessary daily calories = BMR × 1.725
3.3 Energy requirements Our daily energy needs depend on our physical build, sex, age and physical activity. We must acquire the energy necessary to cover our needs, but without overeating, which could lead to weight gain. Our total energy expenditure is the sum of the energy we use for:
Focus on English Sedentary: a person who lives an inactive lifestyle.
• Basal metabolic rate (BMR), which is the minimum amount of energy we need to perform body functions at rest. It maintains body temperature, brain activity, breathing and heartbeat, when there is no physical activity. The basal metabolic rate value varies with size, weight, sex and age. It can also change during pregnancy and breastfeeding.
• The physical activity we do every day. People who live sedentary lives use less energy than people who do intense physical exercise. We also use different amounts of energy depending on the type of physical exercise. For example, walking fast uses 300 kcal/h and running uses 650 kcal/h.
• Digestion and nutrient absorption also require energy which is not included in BMR.
Understand, think, search... 5 Why do you think cells use lipids and not carbohydrates to store energy?
6 If 100 g of carrots contain 90 g of water, 7.30 g of total carbohydrates, 0.90 g of proteins, 0.20 g of lipids, and 2.40 g of fibre, how much energy would juice from 5 carrots weighing 400 grams give?
7 Calculate your daily calorie needs by applying the Harris-Benedict formula. 57
4
EATING
Eating is the process through which we consume the substances (food) that provide us with nutrients. Even though it is voluntary and conscious, eating is part of the nutrition process.
Understand, think, search...
4.1 Eating: basic concepts
1 Explain the difference between
• Diet. Our diet is the food and drinks we consume on a regular
eating and nutrition.
basis and is normally measured in specific amounts or portions. Sometimes we also talk about intake (for example, recommended daily intake), which refers to the amount of nutrients we should consume.
• Portion. This is the approximate, and sometimes inaccurate,
Portion sizes
measurement used to refer to the amount of a specific food that is eaten as part of a diet or when preparing recipes. It is usually expressed in volume or mass measures, in portions such as a slice or a piece, or even in ‘home’ measures like a spoonful or a handful.
Organise the information below into a table and link the name of the portion to its measure (mass, volume, etc.).
Liquids
A pot usually contains 125 ml.
Other measures
A tablespoon A glass can hold 200-250 ml of a liquid contains 20-30 ml. like milk or water.
Solids
This portion of pulses is equivalent to 60 g uncooked and 10 tablespoons cooked.
This portion of pasta is equivalent to 70 g uncooked.
This portion of rice is equivalent to 50 g uncooked.
A handful of nuts can be 20 g.
A knob (or a pinch, a very small portion) of butter, for example, can be 10 g.
A lump of cheese, for example, is 60 g.
A bowl can contain 60-80 g of cereal, 150 g of salad or 240 ml of liquid.
Two handfuls of vegetables, such as carrots, broccoli or tomatoes, is equivalent to 150 g.
Portion A portion can be...
A piece.
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A handful.
A slice.
2 or 3 units would A 110-120 g steak. be approximately 100 g.
1 or 2 eggs, depending on the type.
A 30 g slice or chunk that is 3 fingers wide.
UNIT
2
4.2 Healthy eating Healthy eating is important for many reasons: it provides the necessary nutrients and energy for the body to perform the vital functions; it helps to maintain and restore health; it reduces the risk of disease; it’s important for reproduction, pregnancy and breastfeeding; and it promotes optimal growth and development. When referring to healthy eating, we can also talk about a healthy lifestyle or a healthy or balanced diet. There is not just one concept of a healthy lifestyle, because it can change depending on many factors. Amongst others, these factors include: age, sex, level of physical activity, pregnancy, if you have any illnesses, the time of the year and geographical region.
HEALTHY EATING TIPS: Eat sufficiently. Your food should cover your energy needs, and change depending on the requirements for different stages or situations in life. Eat a range of foods. Your food should contain all the nutrients your body needs and in the correct amounts. Eat a balanced diet. Your food should contain a wide variety of food with good nutritional value like fresh plant produce, and little or no foods of low nutritional value. Prepare food well. Food should be safe to eat without the presence of physical, chemical or biological contaminants, or without exceeding the safe limits set by the responsible authorities.
A healthy diet a)
Mind map. Below you will find some advice for healthy eating. Make a mind map using this information and put ‘healthy eating’ as the main topic. Add the recommendations and expand on them. Learn about this type of diagram for organising ideas in the resource bank at anayaeducacion.es.
b) Design a menu for a day that does not follow any of the advice for a healthy diet. Explain why each food on the menu isn’t healthy.
ting Advice for healthy ea need. vide the energy you • Your diet must pro 30 % from , tes dra m carbohy 55 % should come fro proteins. lipids and 15 % from ct and contain the corre • It should be varied proportions: . all types of nutrients – Foods containing day, it and vegetables a – Five portions of fru nt pla d an s ral ins, mine which provide vitam fibre.
fats. rich in proteins and – Don’t overeat foods me co t s, or those tha Plant proteins and fat on, rdine, anchovy, salm sa from oily fish (tuna, etc.) are better. litres of least one and a half • It must include at lt. sa ch too mu water a day and avoid sting y: a big energy-boo • Eat five meals a da snack pp ; and a lighter su er, breakfast and lunch and dinner.
Eat a nutritionally balanced diet, with the correct proportion of macronutrients. Eat satisfying food, which tastes good and is enjoyable for the senses. Eat a diet that is adapated to your individual, social, cultural and environmental contexts. Eat a diet which is social and affordable. Your diet should allow for social interaction and coexistence, and be economically viable. Eat a sustainable diet. Your diet should have a very low impact on climate change and you should prioritise local products.
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5
DIETARY RECOMMENDATIONS
There are several ways of presenting the recommendations for a healthy lifestyle. The most well-known of these include the food wheel, the healthy eating pyramid and the healthy eating plan. All of them come with the recommendation to do physical exercise and stay well hydrated.
5.1 The food wheel
The food wheel Why do food groups 5 and 6 have a green background, and groups 1 and 2 have a yellow background? Why is the section for group 4 smaller than the section for group 1? Section colour
Food group
Function
1, 2
Energy-producing
3, 4
Body-building
5, 6
Body-regulating
Group 1. Includes grains and grain-based products such as bread or pasta, potatoes and sugar. They are carbohydrate-rich foods, with energyproducing functions.
The food wheel is a visual representation of both the amount and the type of food in a balanced diet. It also includes advice about physical exercise and hydration. The foods are divided into six different-coloured sections (yellow, red and green) that indicate the food group (there are six), the function of the main nutrients (energy-producing, body-building or bodyregulating), and the frequency and amount we must eat (the bigger the section, the more we must eat). This is one of the most common representations of diet recommendations. For example, the Spanish Society for Dietetics and Food Science uses this approach.
Group 2. Includes oils and fats, like butter. They are lipid-rich foods, with energy-producing functions.
Group 3. Includes meat and fish, eggs, pulses and nuts. They are protein-rich foods, with bodybuilding functions.
Group 4. Includes milk and dairy products, like cheese. They are protein-rich foods, with bodybuilding functions.
Group 6. Includes fresh fruit. They are mineral salt and vitamin rich foods, with bodyregulating functions.
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Group 5. Includes vegetables. They are mineral salts and vitamin rich foods, with body-regulating functions.
UNIT
2
5.2 Healthy eating pyramid
Understand, think, search...
The Spanish Society of Community Nutrition (SENC) gives recommendations using the healthy eating pyramid. There are six levels that represent lifestyle, eating and health-related behaviours, and food consumption frequency.
1
There are other ways of representing dietary recommendations for healthy eating. Look at the resource ‘Wheels, pyramids and rhombuses’ in the resource bank anayaeducacion.es and explain what each classification and recommendation is based on.
2
1-2-4. Now that you know what you should eat and how much, prepare a healthy menu for one week.
• The base: actions that maintain a healthy lifestyle like physical activity, emotional balance and adequate hydration.
• The next three levels: foods that should be eaten daily. • The fifth level: foods that should be eaten weekly. • And the sixth level: foods that should only be eaten occasionally and in moderation.
Occasionally and in moderation
The food pyramid Weekly
In addition to indicating how often we should eat foods, the food pyramid can be used to suggest eating-related behaviours like dividing food intake into five meals a day, eating local foods, etc. Can you think of any other behaviours to help us to eat healthily? Suggest at least one.
Dairy: 2-3 a day Others: < 3 a day
Vegetables: 2-3 a day
Daily
Fruit: 3-4 a day
According to physical activity level
Maintain a healthy lifestyle Adequate hydration
Emotional balance
Energy balance
Healthy cooking techniques
Physical activity
Follow advice such as: eat 3-5 meals a day, try to eat local products, eat with other people, cook, etc.
5.3 A healthy eating plan Eating recommendations can also be given as a list or plan with advice for following a healthy lifestyle: Eat a variety of nutritional foods; eat daily: • 4-6 portions of pulses, vegetables, including root vegetables, or nuts. • 2-4 portions of these food groups: grains and grain products; fruits; and meat, fish and eggs. • 2-3 portions of dairy.
• Stay well-hydrated by drinking water, tea and soup, and eating fruit and vegetables. • Ensure that your proteins and fats come from plants, oily fish or white meat, or olive oil. • Limit your consumption of food rich in saturated fats, drinks with added sugars and salts.
• 40-60 g of fat.
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6
FOOD AND SUSTAINABILITY Focus on English Just: adjective to describe behaving in a morally correct way. Optimise: to make the best use of something.
Foods found in the Mediterranean diet
According to the Food and Agriculture Organisation of the United Nations (FAO), a sustainable diet is one which takes into account the environmental component of food as well as its nutritional value and whether it meets food safety criteria.
Sustainable diets have a lower environmental impact. Sustainable diets protect and respect biodiversity and ecosystems. They also meet healthy eating criteria. A sustainable diet should: be culturally appropriate and accessible for all; be economically just and affordable; provide good nutrition and be free from toxic substances; and optimise the use of natural and human resources.
6.1 The Mediterranean diet This is the traditional diet of the Mediterranean region and is an example of healthy eating.
The Mediterranean diet is based on vegetables, olive oil, fish, grains, pulses, potatoes, fruit, yoghurt and fermented milk, as well as water. Do some research about these traditional Mediterranean dishes and explain why they belong to this diet.
The Mediterranean diet Make a list of everything you have eaten in the last 7 days and answer the following questions.
• Recipes based on grains, pulses or potatoes (pasta, rice, lentils, beans, chickpeas, stews, etc.) and that include lots of vegetables (beans, carrots, onions, spinach, etc.) and little protein.
a) Next to each dish, write down whether or not it forms part of Mediterranean diet.
• The main protein sources are fish, poultry, eggs
b) Do any healthy dishes exist that aren’t part of the Mediterranean diet? Justify your answer.
and dairy products. Consumption of red meat, like lamb and beef is much lower.
c) Think about any unhealthy dishes on your list. Can you think of any healthy alternatives to these dishes? d) Plan a menu for 3 days that follows the rules of a healthy diet. Write down whether or not any of the dishes form part of Mediterranean diet.
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It is important to follow the Mediterranean diet, despite the obstacles we face nowadays such as not having enough time to buy food and cook. This is because it can help to prevent diseases linked to nutrition like obesity, cardiovascular diseases, diabetes and some types of cancer. Its main characteristics are:
• Salads are also included in the main meals, using vegetables such as lettuce, tomato and cucumber. The meal normally ends with a piece of seasonal fruit.
• Using olive oil and seasonings, like garlic, parsley, lemon, oregano or pepper, reduces the need for salt.
UNIT
6.2 The Atlantic diet Another sustainable and healthy diet is the Atlantic diet. It is very similar to the Mediterranean diet. Some similarities are:
• The main cooking fat is olive oil. • It includes many foods of plant origin like bread, potatoes, pulses, fruit and vegetables.
• Large amounts of eggs and dairy, are eaten, as well as a moderate amount of meat compared to the much larger amounts of fish and seafood eaten.
2
A traditional and healthy food The Atlantic diet is common in countries with a coast on the Atlantic ocean. They mainly eat fish and seafood, potatoes, grains, pulses, fruit and vegetables such as cabbage, collard greens and rapini.
6.3 Other sustainable and healthy diets There are other ways to eat healthily and sustainably. They all prioritise eating foods obtained following more sustainable production methods. These diets might prioritise:
Bread is one of the best foods nutritionally and has formed the basis of our diet for long. It is highly recommended when made traditionally using wholegrain and unrefined flours, with a low salt content.
• Taking into account the origin and season of foods when eating by choosing local products that have been produced in season. For example, pumpkin, artichoke and sea bass are winter foods, and watermelon and tuna are summer foods.
The main foods eaten are olive oil, fish, fruit and vegetables like ? , pulses like ? , grains like ?
• Using foods of plant origin as a source of lipids and proteins, such as olive and sunflower oil, avocado, oats, nuts, pulses, chickpeas and lentils, etc.
?
• Limiting the consumption of certain foods like sugary drinks, salty snacks or packaged food.
Mediterranean diet
• Using healthier and more sustainable cooking techniques which require less energy, help prevent diseases, etc. For example, eating raw foods and reducing salt or sugar by using aromatic herbs, garlic, lemon, cinnamon, etc. as seasonings or dressings.
Understand, think, search... 1
The Mediterranean diet has been declared as Intangible Cultural Heritage of Humanity. Find out and explain what this recognition means and why it was awarded.
Atlantic diet
Examples of healthy eating
Healthy and sustainable eating
Sustainable eating practices
2 Draw a calendar of seasonal foods. Include at least one fruit, one vegetable and one fish for each month.
3 Suggest ways of reducing salt and sugar consumption. 4
Concept map. Fill in, expand and link the ideas in the diagram on the right to different ways of eating sustainably and healthily. Learn what this type of diagram for organising ideas consists of by looking at the resource bank at anayaeducacion.es.
Eat local and seasonal products.
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7
DIET AND HEALTH
Food security is the access people have at any time to nutritionally suitable and safe foods in sufficient quantity and quality in order to have a healthy and active life. How we eat, including the types of food, the variety, the amount and their nutritional value, affects our health. These effects on our health mean that diet is also related to food safety.
We can improve our health by living healthy lifestyles. For example, our diet can help to prevent diseases like cancer, atherosclerosis, stroke and many more.
The effects can be positive if they support good health (help to prevent or cure diseases, for example). Or they can be negative if they cause diseases linked to a lack or excess of nutrients and energy like malnutrition, or the presence of harmful substances which would mean that the foods were unsafe, as in the case of food poisoning.
7.1 Malnutrition Malnutrition is caused by an unsuitable diet that has a deficit or surplus of nutrients or energy. This causes changes such as undernutrition or overnutrition, deficiency diseases, and more.
Undernutrition
Having anaemia caused by low red blood cells is something that we can prevent by eating a healthy and varied diet. The illness causes weakness and tiredness.
Undernutrition occurs when eating unsuitable foods leads to a lack of energy. This causes the body to use its carbohydrate and lipid reserves and, in severe cases, causes the loss of structural proteins, which can lead to death. Disorders related to undernutrition include rickets; anorexia nervosa, which is a psychological disorder that has serious health effects and is characterised by refusing to eat for fear of gaining weight; and bulimia, which is also a psychological disorder characterised by compulsive craving for food, followed by binge eating and purging (vomiting) due to guilt, fear of gaining weight, etc.
Understand, think, search...
Overnutrition
1 What are the dangers of eating too much
Overnutrition usually occurs when too much food is eaten, providing an excess of nutrients and energy that are eaten. These are then stored and usually lead to negative health effects.
food and having a sedentary lifestyle?
2 What
is the difference between malnutrition and undernutrition?
3
Find the meaning of these terms related to malnutrition: rickets, marasmus, cachexia and emaciation.
4
Where do you think xerophthalmia or childhood blindness, which is a disease cause by a lack of vitamin A, is most common? Suggest at least one measure to prevent it.
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One of the most common effects of this type of malnutrition is obesity, which is a disease characterised by the accumulation of excess body fat. Other diseases like cardiovascular diseases (atherosclerosis), cancer and diabetes are linked to obesity and can be made worse by it.
Deficiency diseases These diseases are caused by a limited or inadequate diet, that lacks certain nutrients. The most common are avitaminosis (vitamin deficiency) or iron deficiency anaemia.
UNIT
2
7.2 Food allergies and intolerances
Understand, think, search...
Some people have adverse reactions (intolerances or allergic –defence– reactions to substances that should be safe) when they eat certain foods. The most common ones are lactose intolerance, which is a reaction to lactose, a sugar found in milk, and coeliac disease, or gluten intolerance, which is a reaction to gluten, a protein found in wheat. The most common food allergies are to nuts, eggs and seafood.
5 List five foods that people with lactose
7.3 Diseases and food safety Sometimes there are substances or microorganisms in food that are harmful to people’s health. When we eat them, they cause food-borne diseases or food poisoning. These contaminating substances are linked to unsafe foods. This contamination normally takes place in the food chain or is due to environmental pollution. Laws set the maximum amounts allowed for this type of substance.
intolerance and people disease cannot eat.
with
coeliac
6 What are food additives? Find out what they are and give at least one example.
7
The Prediction. What can happen if you do not wash or peel fruit before eating it, even if it looks clean?
8
Look at ‘What foods contain food contaminants’ in your resource bank at anayaeducacion.es. Then link the mentioned substances or microorganisms that cause diseases to the food on this plate.
Food safety is the name for the measures taken to ensure safe foods and prevent the presence of substances that cause diseases. Food safety measures include washing foods that we eat raw, cleaning utensils used for cooking or eating, putting foods that need to be kept cold in the fridge, etc. Food contaminants, depending on their origin, can be biological, chemical or physical.
Biological contaminants These include organisms that cause diseases like the bacteria Salmonella, which causes salmonellosis, the worm Taenia solium, which causes taeniasis and the larvae of the worm Anisakis which causes anisakiasis.
Biological contaminants
Other biological contaminants are toxins like the botulinum toxin which causes botulism and is produced by the bacteria Clostridium botulinum, and the aflatoxin produced by some fungi of the Aspergillus family.
Chemical contaminants Some food additives can be toxic. Other substances like pesticides and heavy metals, like lead or mercury, are environmental pollutants. They are related to diseases like cancer, some neurological disorders and so on.
Physical contaminants Sometimes there are physical contaminants such as pieces of glass, metal or wood in food that can cause injuries to people who eat them.
Salmonella
Anisakis
Chemical contaminants
Taenia solium
Aspergillus toxin
Physical contaminants
Mercury Pesticides
Pieces of glass
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rtfolio.
po unit for your ces from this choose resour to r be em m Re
E S I T C A R P D N A W REVIE UNDERSTAND
Interpreting pictures
Organising your ideas
3 Look at the pictures below and answer the
1
Attributes wheel. To help organise your ideas copy the following diagram into your notebook and fill it in. Learn how to make an attributes wheel using the resource available at anayaeducacion.es.
Must provide the necessary energy ?
Eat five
?
questions: B C
A
Must be varied ?
D
F E
– Eat carbohydraterich foods like ? – Eat five portions of ? – Do not overeat ?
Healthy eating
a) Which nutrients are shown? b) What are their functions in the body?
The most calorie dense ? and the lightest ?
Drink
c) What foods can they be obtained from?
?
Avoid
4 The following graphs show the composition of four ?
types of food. Compare them and match each one to these foods: butter, strawberries, chicken breast, cake. Give reasons for your answers. A
B
C
D
Summarising 2 Write your own unit summary based on the outline below:
• Give a definition of nutrition; then name and briefly explain the processes necessary to perform it.
• Name the systems involved in nutrition and specify the function of each one.
• Name the functions of the nutrients. • Explain the types of nutrients according to their chemical composition.
• Explain why energy requirements are not the same for everyone.
• Describe a healthy diet. • Explain the food wheel and what it is used for. • Explain the food pyramid and food plan and what they are used for.
• Describe the characteristics of sustainable diets
Water
Proteins
Lipids
Carbohydrates
Fibre
5 Look at the following pictures of food and answer the questions: a) For which nutrients are they food sources? b) What functions do the nutrients they contain perform in the body? c) Which of these foods must be eaten daily and which must be eaten occasionally?
and give two examples of this type of diet.
C
B
A
• Name the types of malnutrition and briefly describe them.
• Explain what a food intolerance is. • Explain the consequences to your health of bad food safety. 66
D
E F
UNIT
Applying your knowledge
2
Moving forward
6 What is the difference between:
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a) eating and nutrition? b) organic and inorganic nutrients?
Explain the meaning of this sentence: ‘There are many different ways of eating, but only one way to obtain nutrients.’
12 Prepare a diet based on what you eat every day.
c) macronutrient and micronutrient?
List everything you eat and the approximate amounts of each food. Then answer the questions below:
d) handful and portion? e) food wheel and the healthy eating pyramid?
7 Copy and correct the following incorrect sentences
a)
about nutrients: a) Water is important because of the energy it provides. b) We need vitamins in large amounts. c) Fruits are rich in lipids. d) Proteins are made up of amino acids and only have a defensive function.
b) Calculate the energy content of your daily diet.
8 Classify the following foods depending on whether it has body-building, energy-producing or bodyregulating functions: peppers, fish fillet, chocolate, fruit, apple tart and egg.
Think about the information found in the resource ‘Food nutrition table’ which is in your resource bank at anayaeducacion.es and list the nutrients and energy content of the foods in each part of the diet you prepared.
c) Study your diet and assess whether it meets the requirements of a balanced diet.
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a) Rice or potatoes or grains
e) Water
b) Olive oil
f) Vegetables
Research which foods could be found in the Middle Ages in Spain. List some of them and prepare a menu for one day. Compare it to one you would find today and discuss the differences from a healthy and sustainable eating point of view. To help you answer, think about these aspects:
c) Fruit
g) Pulses
• Variety of foods
9 State what daily portions are the most suitable for the following foods:
d) Meat or fish
10 Explain what anorexia and bulimia are and describe their consequences.
• Origin of foods • Food safety
REFLECT ON YOUR LEARNING In this unit you have analysed the nutrients in the food students bring to school. You have also created a system for classifying food and checked how healthy your eating habits are. You have also put your knowledge of healthy diets into practice by thinking of a healthy and nutritious eating plan. Now reflect on your learning by filling in the self-assessment worksheet at anayaeducacion.es. Topics
I understand this and could explain it to my classmates
I don’t fully understand this. I still have some doubts
I don’t understand I’m not sure this
I understand the energy content of food and know that it should match the energy needs of an individual.
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TEST YOURSELF Go to anayaeducacion.es and complete the self-assessment worksheet to test your competencies. 67
G L O S S A RY A Anorexia nervosa A psychological disorder where a person rejects food, leading to malnutrition and extreme thinness.
B Basal metabolic rate The minimum amount of energy we need to perform our vital functions at rest.
Food chain The process a food item goes through from the moment it is produced until it reaches the table. The steps it goes through are: production, storage, transport, industrial processing and commercialisation. Food portion An amount of food that meets a person’s nutritional requirements. Portion size depends on many factors and is not the same for everyone.
Men BMR = (10 × mass in kg) + (6.25 × height in cm) – (5 × age in years) + 5 Women BMR = (10 × mass in kg) + (6.25 × height in cm) – (5 × age in years) – 161
Bulimia Psychological disorder where a person compulsively eats large quantities of food in secret and then purges it through vomiting.
C Calorie The amount of heat needed to raise the temperature of one gram of water by 1 °C. Calories are denoted by the abbreviation cals.
Food security When all people, at all times, have access to nutritious food in sufficient quantities and of sufficient quality to lead a healthy life.
E
Food source A food that contains large amounts of a given nutrient.
Eating The voluntary and conscious ingestion of food that we choose depending on our environment and that provides us with nutrients. Energy value of a food The value proportional to the amount of energy provided by a food when it is burnt in the presence of oxygen.
F Food additives Substances that are added to food and food preparations to preserve their properties (taste, colour, etc.), restore qualities they may have lost, and prevent them from decaying. Some additives may be harmful to health.
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H Healthy eating Food that provides people with enough energy and nutrients to perform their vital functions, achieve optimal growth and to maintain or recover their health.
UNIT
2
I
O
Intake Used to talk about the proportions and amount of food consumed.
Obesity A disease characterised by the accumulation of excess body fat. It occurs when a person consumes too much energy in the form of carbohydrates and fat.
J Joule Unit of energy, work and heat used in the International System of Units. Joules are denoted by the letter J, and 1 J is equal to 0.24 cals.
P Pesticide A substance used to control animal or plant pests.
M Macronutrient A nutrient that the body needs in large amounts, such as fats, proteins, carbohydrates and water. Malnutrition Poor nutrition due either to food deficiencies or to excessive consumption of food. Micronutrient Nutrient that the body needs in very small amounts, such as minerals and vitamins.
N Nutrients The chemical components of food that our bodies can use once they have digested them and absorbed them through the process of digestion.
proteins
Plant or dietary fibre A type of polysaccharide which is found mainly in vegetables and which we cannot digest. This means that it is not considered a nutrient, although it is necessary for healthy gut function.
R Rickets A disease caused by a lack of vitamin D that manifests as stunted growth, curved bones and general weakness.
T Toxin A poisonous substance produced by microorganisms.
carbohydrates or complex sugars
Nutrition The process by which our bodies extract the nutrients they need from food, and transform them to obtain the substances and energy required to build and maintain their structures and carry out their functions.
Aspergillus toxin
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