What makes a balanced diet?
What makes a balanced diet?
A balanced diet is a diet that consists of a variety of foods. It should be based on bread, potatoes, cereals and lots of fruit and vegetables. You should also have a moderate amount of milk and dairy products, meat, fish or other alternatives (if vegetarian/vegan). It should contain a limited amount of fat and sugar.
Eating a healthy diet can help to prevent obesity, malnourishment and vitamin deficiencies. It can enhance you overall well being and prevent a number of diseases and cancers.
It is important that you consume a wide variety of foods to maintain adequate intakes of vitamins, minerals and dietary fibre, as these are important to your health.
Protein is needed for growth and repair of the body and it also gives us energy. Amino acids are the building blocks of protein and different foods contain different amounts of these.
Different foods vary in the amounts of protein that they provide. The main sources of protein are meat, fish, eggs, milk, cheese, cereals and cereal products (e.g. bread), nuts and pulses (beans and lentils). A majority of protein can be obtained from animal sources i.e. meat, fish, eggs and dairy products. Further protein can be obtained from cereal products, and nuts and pulses. The following chart shows the percentage of protein that is in each food.
Protein is broken down by digestion into amino acids, which are then absorbed through the intestine wall and used to make other proteins in the body.
Sometimes the amino group of an amino acid is transferred to another molecule by transamination. This is were the human body is able to make some amino acids for itself. These are known as non-essential amino acids.
However, not all amino acids can be made in the body. A certain number must be supplied by the diet. These are known as the essential amino acids and for the human adult there are eight:
• Leucine
• Isoleucine
• Valine
• Threonine
• Methionine
• Phenylalanine
• Tryptophan
• Lysine.
In children, Histidine is also considered to be an essential amino acid, since children are unable to make enough to meet their needs.
Carbohydrates
Carbohydrates provide us with energy and are mainly found in cereals and cereal products. Carbohydrates have been broken down into two types for dietary purposes.
. Sugars.
- This includes sugars that are intrinsic, and incorporated in the cellular structure of foods such as fruit and vegetables.
- Also extrinsic sugars, i.e. sugars not bound into a cellular structure. Honey, fruit juices, table sugar and confectionery are examples of foods containing extrinsic sugars.
2. Complex carbohydrates
- Starch, which can be found in potatoes, bread, rice and pasta.
- Fibre, which is a mixture of substances, mainly complex carbohydrates, which cannot be digested in the small intestine by humans.
Fat
Fat is a concentrated source of energy (9 kcla per gram compared with 4 kcal per gram in carbohydrate) and provides more than double that provided by either protein or carbohydrate. It is a carrier for fat-soluble vitamins A, D, E and K.
Fat contains the essential fatty acids (EFAs), linoleic acid (n-6) and alpha linolenic acid (n-3). These are called the Essential Fatty Acids (EFAs) and must be supplied in the diet, as they are important for the formation of cell membranes particularly in nerve tissue.
'Saturated fat is fat that consists of triglycerides containing only saturated fatty acids'1.
Fat that occurs naturally in animals and plants contains a varying proportion of saturated and unsaturated fat. All fats contain both saturated and unsaturated fatty acids but are often described as 'saturated' or 'unsaturated' according to the magnitude of fatty acids present. For example, butter is often described as a 'saturated fat' as it has more saturated fatty acids than unsaturated fatty acids, whereas most vegetable oils are described as 'unsaturated fats' since they have more mono- and polyunsaturated fatty acids than saturated.
Diets high in saturated fat have a high correlation with high cholesterol, Coronary Heart Disease and hardening of the arteries.
'An unsaturated fat is a fat or fatty acid in which there is one or more double bond in the fatty acid chain'2.
Saturated fats are popular with manufacturers of processed foods because they are more solid at room temperature and are less vulnerable to rancidity than unsaturated fats. This makes them more profitable to produce.
Vitamins
Vitamins are needed in very small amounts (usually only a few milligrams) for the essential processes carried out in the body.
Most vitamins are provided by the diet. Except for vitamin D, which can be obtained by the action of sunlight on the skin. Small amounts of a B vitamin (niacin) can be made from the amino acid, tryptophan.
Vitamin K
Vitamin K is found in foods from both plant and animal sources and is also made by bacteria in the intestines. Vitamin K is essential for blood coagulation and is required for normal bone structure. Deficiency is very rare in adults, unless the intestines are damaged. Deficiency is sometimes seen in newborn babies. To prevent this, babies are injected with vitamin K shortly after they are birth.
Folic Acid
Folic acid is essential for cell division and the formation of blood cells. Pregnant women need to increase their intake of folic acid, as ...
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Vitamin K
Vitamin K is found in foods from both plant and animal sources and is also made by bacteria in the intestines. Vitamin K is essential for blood coagulation and is required for normal bone structure. Deficiency is very rare in adults, unless the intestines are damaged. Deficiency is sometimes seen in newborn babies. To prevent this, babies are injected with vitamin K shortly after they are birth.
Folic Acid
Folic acid is essential for cell division and the formation of blood cells. Pregnant women need to increase their intake of folic acid, as it is needed for the normal structure of the nervous system and specifically in the development of the neural tube in the developing embryo.
Minerals
Minerals are natural compounds that are required for the formation of bones and teeth, as constituents of bodily fluids and tissues and constituents of enzyme functions and nerve function.
Some minerals are required in greater amounts than others e.g. calcium, magnesium, sodium, potassium and chloride. Others are required in smaller quantities (trace minerals) e.g. iron, zinc and copper. Despite being required in smaller amounts they are no less important than other minerals.
To avoid deficiencies people need to have a varied and balanced diet.
Calcium
Calcium is the principle mineral in the formation of bones and teeth. It also plays an essential role in intracellular signalling and thus is necessary for nerve and muscle function. It is also involved in blood clotting. Foods such as milk, cheese and other dairy products are well known for containing calcium.
Insufficient calcium in bones can result from an inadequate supply of vitamin D, which is essential for its absorption. In children, vitamin D deficiency results in rickets and in adult's osteomalacia, in which bones become weak owing to lack of calcium.
Long-term calcium deficiency can lead to osteoporosis (particulary common in elderly people), in which the bone deteriorates and there is an increased risk of fractures.
Phosphorous
Phosphorus can be found in all plant and animal cells, and 80% of the phosphorus in the body is present as calcium salts in the skeleton. It is essential for bone and tooth structure, for the structure of cell membranes (in phospholipids) and for energy metabolism.
Iron
Iron can be found in animal and plant sources, such as meat, fish, poultry, lentils, beans, leaf vegetables, tofu and chick peas.
Iron from animal sources (haem iron) is better absorbed than iron from plant sources (non-haem iron). Vegetarians and vegans are at risk of developing anaemia if they don't eat a well balanced diet.
Iron is required for the formation of haemoglobin in red blood cells, which transport oxygen around the body. Iron is also required for normal energy metabolism, and for metabolism of drugs and foreign substances that need to be removed from the body. The immune system also requires iron for normal function. A lack of iron leads to low iron stores in the body and eventually to iron deficiency anaemia.
Zinc
Zinc is present in many foods and is most readily absorbed from meat. It is essential for cell division and, therefore, for growth and tissue repair. It is also necessary for normal reproductive development. Zinc is also required for the functioning of the immune system and in the structure and function of the skin and, therefore, in wound healing.
'Obtaining a sufficient zinc intake during pregnancy and in young children is a very real problem, especially among those who cannot afford a good and varied diet'3.
Water
Over half the human body consists of water and regular fluid intake is essential for our bodies to work properly. Human beings would be unable to survive without it.
We can obtain our fluid requirements from a number of sources such as water and other drinks, as well as from the food we eat.
Dehydration can impair physical performance, and in extreme cases can be fatal. Symptoms of mild dehydration include headaches and fatigue.
Experts recommend that you drink 2 litres of water a day. The amount of fluid needed varies between people and according to age, time of year, climatic conditions, diet and levels of physical activity.
Fibre
Dietary fibres are the indigestible portion of plant foods that move food through the digestive system, absorbing water4.
Dietary fibre can be found mainly in cereal foods, beans, lentils, fruit and vegetables. It comprises the edible parts of plants that are not broken down and absorbed in the human small intestine.
Fibre can help to prevent constipation, lower blood cholesterol levels and control blood glucose levels.
Specific dietary needs of children, pregnant women and nursing mothers.
Dietary Reference Values (DRVs) are a series of estimates of the amount of energy and nutrients needed daily by different groups of healthy people in the UK population. Although these standards are set for everyone, the amount that each person receives will vary due to age, gender, state of health, level of activity and life style choices.
Included within this definition are three types of estimates: Reference Nutrient Intakes (RNIs), Estimated Average Requirements (EARs) and Lower Reference Nutrient Intakes (LRNIs).
Reference Nutrient Intakes (RN1s) are used for protein, vitamins and minerals, and are an estimate of the amount that should meet the needs of most of the group to which they apply. They are not minimum targets.
The Estimated Average Requirements (EAR) is an estimate of the average requirement for energy or a nutrient - approximately 50% of a group of people will require less, and 50% will require more. For a group of people receiving adequate amounts, the range of intakes will vary around the EAR.
The Lower Reference Nutrient Intakes (LRNI) is the amount of a nutrient that is enough for only the small number of people who have low requirements (2.5%).
Children have a high-energy requirement for their size, because they regularly go through rapid 'growing spurts' and are very active. To get all this energy they need eat foods that are high in energy (and also rich in nutrients). Younger children need eat them as a part of small and frequent meals, because they do not have large enough stomachs to cope with big meals.
A good supply of protein, calcium, iron and vitamins A and D is also necessary during this time. Calcium is needed for healthy tooth development and, together with vitamin D, helps make bones stronger. Childhood is an important time for tooth and bone development.
Children need to be encouraged to take responsibility for their dental hygiene and ways of preventing dental cavities. They should be encouraged to eat less foods and drinks containing sugar and, where possible try to have them only at meal times.
Iron deficiency anaemia is associated with frequent infections, poor weight gain and delay in development.
Iron rich foods, such as liver and red meat, are not always popular with children, so other more appetising ways of providing iron may need to be found, e.g. offering pâté or minced meat burgers. Children who are vegetarian must have alternative sources of iron, such as dark green leafy vegetables, pulses and nuts. However children are not very fond of leafy vegetables such as spinach. Some bread and fortified breakfast cereals contain iron though.
Pregnant women
Pregnant women do not need to 'eat for two'. The estimated average requirement for energy (EAR) increases during the last three months of pregnancy by an average of 200 kcal per day. The needs of individual women will vary, depending on how active they are. At this time a woman is less active. If food intake is very low at this stage and fat stores are low, the foetus will grow more slowly and the baby may have a low birth weight.
An expectant mother requires a healthy and varied diet to provide her and her growing foetus with the full range of nutrients. The diet must provide for both the mothers usual needs and provide extra for the growth of the breasts, foetus, uterus and placenta. The mother also needs to lay down stores of nutrients to help the growth of the foetus, and for lactation.
The table below explain the nutritional needs of pregnant and breast-feeding woman and also what foods avoid.
Nutrient,
Bacteria or other.
Needs
Avoid
Iron
Pregnant women need more Iron for the growth of the placenta and foetus. They should eat plenty of foods containing iron such as red meat, fortified breakfast cereals, pulses, breads and green vegetables.
Iron deficiency anaemia during pregnancy can increase the risk of the baby having a low birth weight and developing iron deficiency anaemia during the first year or two of life.
Vitamin A - It is not recommended that they eat liver or pâté as they may contain large amounts of vitamin A. Large intakes of vitamin A during early pregnancy has been linked to birth defects. Women who are pregnant, or who might become pregnant, should not take vitamin A supplements unless they are advised to do so by a health professional.
Breast-feeding women are also advised to take supplements containing 10 micrograms of vitamin D each day.
Listeriosis
Listeriosis is a rare flu-like illness caused by bacteria called Listeria monocytogenes. It may cause miscarriage, stillbirth or severe illness in the newborn baby. To avoid thus, pregnant women are advised not to eat food such pâté's and blue-veined and soft cheeses, because high levels of bacteria have been found in these foods. There is no risk associated with hard cheeses such as Cheddar of Cheshire, or cottage cheese, processed cheese or cheese spread. it is also recommended that pregnant women re-heat ready-cooked meals (especially those containing poultry) until they are piping hot.
Pregnant women should make sure that they wash fruit and vegetables well, especially if they are to be eaten raw.
Toxoplasmosis
Toxoplasmosis is an illness caused by a parasite that can be found in cat faeces. The parasite can also be present in raw meat and occasionally goat's milk. The illness can in rare cases be passed to the unborn baby via its mother, resulting in a range of problems, some of them serious. As a safeguard, pregnant women should not eat raw or undercooked meat, unpastuerised goat's milk or goat's cheese, or unwashed raw fruit and vegetables.
Salmonella
To avoid salmonella, pregnant women should avoid eating raw eggs or food that contains eggs that are raw or partially cooked. Eggs should be cooked until both the white and yolk are solid. Raw meat and chicken can also be a source of salmonella bacteria. All meat, especially poultry, should be thoroughly cooked and it is important to avoid contamination of other foods.
Caffeine
High levels of caffeine can result in babies having a low birth weight, or even lead to pregnant mothers miscarrying. Pregnant women need to limit the amount of caffeine they consume to no more than 300 mg a day (4 cups of coffee). They also need to be aware that Caffeine is added to some soft drinks and energy drinks, as well as occurring naturally in foods such as coffee, tea and chocolate.
Alcohol
Drinking alcohol during pregnancy can damage the unborn child. It is recommended that to minimise the risk to the unborn child, women who are trying to become pregnant or are at any stage of pregnancy should not drink more than 1 or 2 units of alcohol once or twice a week.
Fish
It is recommended that an adult eat at least two portions of fish per week, one of which should be oily fish. This also applies to pregnant and breast-feeding women, but they should limit oily fish to up to 2 servings per week.
The consumption of fish, particularly oily fish, can help to prevent heart disease. This is because omega 3 and polyunsaturated fats can be found in large amounts in oily fish. Omega 3 is required for the development of the central nervous system in the foetus and young infant, so are important for both pregnant and breastfeeding women.
Pregnant and breast-feeding women should avoid eating marlin, swordfish and shark because of potential exposure to mercury, which at high levels can damage a babies developing nervous system.
Pregnant women should also limit the amount of tuna that they eat to no more than 2 tuna steaks per week or 4 medium-sized can a week, as it also runs the risk of exposure to mercury.
Peanuts
If the mother or another member of the family suffers from an allergic disease such as eczema, asthma or hay fever it is advised that peanuts or foods containing peanuts are avoided during pregnancy and breast-feeding.
Breast-feeding is the best method for feeding babies. Breast milk provides all the energy, liquid and nutrients the baby needs for growth and development.
The milk from breast-feeding contains energy in the form of protein, fat and carbohydrate. Therefore breast-feeding women require energy and nutrients. It is important to have a well-balanced and varied diet and drink plenty of fluids.
Breast-feeding uses up about (500 kcals) a day and this can help to loose any excess weight gained during pregnancy. It is also important for psychological and immunological factors.
The Balance of Good Health model is a pictorial guide showing the proportions and types of food that are needed to make up a healthy balanced diet (see picture below 5). The guide is divided into five food groups: bread, other cereals and potatoes; fruit and vegetables; milk and dairy foods; meat, fish and alternatives; foods containing fat and foods containing sugar. Foods from the largest groups should be eaten most often and foods from the smallest group should be eaten least often. The guide is shaped like a dinner plate that has been designed to make healthy eating simpler to understand and interpret.
The Healthier Nation government initiation is an action plan aimed at tackling poor health and unnessesary deaths as a reslt of unhealthy lifestyles. Particularly for those who are worst off in society. The targets set aim to reduce deaths caused by the four main killers, cancer, coronary heart disease and strokes, accidents and mental illness. They aim to do this by increasing peoples physical activity, getting them to eat a healthy balanced diet and tackling smoking.
The four main aims of the initiative are for people to ...
. Eat less saturated fat
2. Eat less salt
3. Less Sugar
4. More fibre
Children need to eat low amounts of sugary foods, and when they are eaten they should be eaten in small amounts. Many snacks foods are high in calories, fat and sugar, but don't contain many of the essential vitamins and minerals that children need to grow. Also, sugary foods and drinks (including fruit juice) can significantly contribute to dental decay.
Parents should try to limit the amount of sugar and sweets their children eat. If they are eaten, they should be offered at the end of a meal rather than in between.
Babies and children should not eat large quantities of salt because they do not have the capacity to process large quantities of salt, as the kidneys are not yet developed.
If they are given adult food with a higher salt content before they are at least four months old, excess sodium can accumulate in the body, causing kidney, liver and brain damage, and in very occasional cases, death.
It is recommended that babies are given only milk, whether breast or formula, for the first four months of life.
Children should be encouraged to not add salt to their food by not putting the salt pot on the table.
Pregnant women need to comply with all four of these, as they especially need a balanced diet for the growth of the foetus. Pregnant women also need a diet that is high in fibre, as pregnant women tend to experience constipation. Eating foods high in fibre helps to relieve this.
Breast-feeding
Breast-feeding has a range of health benefits both for the mother and child. It can be difficult at first but with perseverance you will begin to find it convenient and easy.
Breast-feeding has many advantages.
* It protects your child from infection and some diseases.
* Breast-feeding helps to mobilise fat stores and helps with post-birth weight loss. Breast-feeding burns 500 calories a day.
* It is convenient - it needs no preparation and it's free.
* Breast milk provides your baby with all the nutrients that they need.
Research has found that the average person in the UK eats less than 3 portions of fruit and vegetables a day, instead of the recommended 5. This is even lower amongst young people. The government initiative 5 A DAY programme and website aims to change the way people think, and highlight the healthier benefits of eating more fruit and vegetables.
They want to teach people that eating more fruit and vegetables is good for your health. And that eating a good combination of 5 portions of fruits and vegetables a day ensures that you get all the nutrients that you need and prevents disease and illness.
Children especially need to be encouraged to eat 5 a day as they need a well balanced diet with essential nutrient to help their growing bodies.
Here are some benefits of eating '5 a day' from the '5 a day' website (www.5aday.nhs.uk).
'Here are 5 great reasons to eat 5 portions of fruit and vegetables A DAY
* They're packed with vitamins and minerals.
* They can help you to maintain a healthy weight.
* They're an excellent source of fibre and antioxidants.
* They help reduce the risk of heart disease, stroke and some cancers.
* They taste delicious and there's so much variety to choose from.'
The 'Food in Schools' programme is a joint venture set up by the Department of Health and the Department of Edcuation and Skills to help schools implement a whole school approach to food education and healthy eating. A whole range of nutrition-related activities and projects are being developed as part of the programme, to complement and add value to existing healthier food initiatives in schools. (see unit 17)
. www.wikipedia.org/wiki/Saturated_fat
2. www.wikipedia.org/wiki/Unsaturated_fat
3. www.wikipedia.org/wiki/Zinc#Zinc_deficiency
4. www.wikipedia.org/wiki/Dietry_fibre
5. www.lbhf.gov.uk/Images/healthy-meal_tcm21-38557.jpg
OCR Level Health, Social Care & Early Years Unit 6
Rachael Crossland
