Tuesday, March 15, 2011

The human life cycle

 Wordle: nutrition through the life cycle

 

 

The Life Cycle



A life cycle is defined as the cycle of an organism's growth, reproduction and eventual death. The human life cycle refers to humankind's journey from the stages of fertilization until the cycle concludes in their deaths. There are five stages to the human life cycle. The following is an overview of each phase in the cycle.

  1. Birth

    • The first stage of the human life cycle, referred to as birth, actually begins at conception. When sperm reaches and is able to fertilize a female's egg, the first building block of life is created in the form of a one-cell organism called a zygote. This single cell with divide and multiply itself countless times over the next 40 weeks, until the actual birth occurs. These divisions of cells are what form the various parts of our bodies. Every part of us begins from that one tiny cell.

    Infancy

    • The second stage in the life cycle is rinfancy. This stage lasts from birth until we are 1 year old. During our first year, we are totally dependent on others to meet our every need. The infancy stage is the most formidable one in the cycle because it's the stage in which we learn the most basic life skills which we will carry with us throughout our life cycle.

    Childhood

    • The third stage of the life cycle is childhood. This stage begins as we enter into our second year of life and continues for the next 10 years. This is the stage in which we develop the male and female traits that we will carry with us through the rest of our lives. We also develop social skills and personality traits that will define who we are.

    Adolesence

    • The foruth stage in the cycle of life is adolescence. This stage begins at age 12 and lasts through the 18th year of our lives. During this phase, our bodies develop male and female traits such as menstrual cycles, facial hair and voice changes. The onset of the development of these traits is called puberty.

    Adulthood

    • The fifth and final stage of the life cycle is adulthood. This stage begins at age 18 and lasts until our death. By this time, barring afflictions such as birth defects and mental retardation, we are fully formed, functional human beings capable of maintaining ourselves and sustaining life. It is during this stage of our lives that we begin the life cycle once again by having children and grandchildren of our own.


References



Resources


Fact sheet

Food and your life stages - Better Health Channel

Our nutritional requirements change as we move through different life stages. Adolescence, pregnancy, lactation, menopause and ageing all place extra demands on the body. These demands need to be met by our daily diet to maintain the best of health. 



Food and your life stages

Our nutritional needs change with different life stages. To be fit and healthy, it is important to take
into account the extra demands placed on your body by these changes.
To meet your body’s regular nutritional needs, you should consume:
• A wide variety of nutritious foods
• Water on a daily basis
• Enough kilojoules for energy, with carbohydrates as the preferred source
• Adequate protein for cell maintenance and repair
• Fat-soluble and water-soluble vitamins
• Essential minerals such as iron, calcium and zinc
• Foods containing plant-derived phytochemicals, which may protect against heart disease,
diabetes, some cancers, arthritis and osteoporosis.

A varied diet that concentrates on fruits, vegetables, whole grains, legumes, dairy foods and lean
meats can meet these basic requirements.

Babies – birth to six months of age
Infants usually double their length and triple their weight between birth and one year of age.
Breast milk generally supplies a baby with the required amounts of nutrients, fluids and energy up
to about six months of age. Where possible, breast milk is preferred to formula, as it contains
many protective and immunological factors that benefit the baby’s development.
Breast milk or correctly prepared infant formula provides enough water for a healthy infant to
replace any water losses. However, all infants need extra water once solid foods are introduced.
Babies – six to 12 months of age
Solids should be introduced around six months of age. Different societies have their own traditions
about which food is more appropriate to start with – culturally appropriate foods and preparation
methods should be encouraged when these are nutritionally adequate.
As a baby is gradually weaned from the breast or bottle and new solids are introduced, there may
be reduced body stores of iron. To maintain nutrient body stores:
• Give your baby foods that are rich in iron, such as iron-enriched infant cereals. Ironenriched
rice-based cereals are frequently recommended as the first food to be introduced,
as there is the additional benefit of a lower risk of an allergic reaction.
• Fruits and vegetables should be introduced after the cereals. They are important for
vitamin and mineral content and to introduce new textures, tastes and colours.
• Meat, poultry, fish and whole eggs are generally introduced last.
• Don’t add salt or sugar to your baby’s food, it is unnecessary.
• Avoid cow’s milk as the main drink in the first 12 months.
• Introduce foods one at a time. Offer new foods once every three to four days to avoid
confusion and to rule out food allergy and sensitivity.
• Feed babies during illness and feed up after illness. Give ample liquids if your baby has
diarrhoea.
• Occasional exposure of the skin to sunlight is usually enough to provide a baby’s vitamin D
requirements but this does vary from season to season and with skin colour.
Young children
Once a child is eating solids, offer a wide range of foods to ensure adequate nutrition. Young
children are often picky with food but should be encouraged to eat from a wide variety of foods.
Food and your life stages Page 1 of 4
During childhood, children tend to vary their food intake (spontaneously) to match their growth
patterns. Children’s food needs vary widely, depending on their growth and their level of physical
activity. Like energy needs, a child’s needs for protein, vitamins and minerals increase with age.
Ideally, children should be accumulating stores of nutrients in preparation for the rapid growth
spurt experienced during adolescence.
Food-related problems for young children include overweight, obesity, tooth decay and food
sensitivities.
Recommendations include:
• If a child is gaining inappropriate weight for growth, limit energy-dense, nutrient-poor
snack foods. Increase your child’s physical activity. You could also limit the amount of
television watching.
• Tooth decay can be prevented with regular brushing and visits to the dentist. Avoid sugary
foods, especially if sticky or acidic.
• Ensure your child has enough fluids, especially water.
• Be aware of foods most likely to cause allergic reactions, including peanuts, shellfish and
cow’s milk. Be particularly careful if there is a family history of food allergy.
Children entering their teenage years
The growth spurt as children move into adolescence needs plenty of kilojoules and nutrients. For
girls, this generally occurs around 10 to 11 years of age. For boys it occurs later, at around 12 to
13 years.
Recommendations include:
• The extra energy required for growth and physical activity needs to be obtained from foods
that also provide nutrients instead of just ‘empty calories’.
• Takeaway and fast foods need to be balanced with nutrient-dense foods such as wholegrain
breads and cereals, fruits, legumes, nuts, vegetables, fish and lean meats.
• Dairy products should be included to boost calcium intake – this is especially important for
growing bones.
Older teenagers and young adults
Moving away from home, starting work or study, and the changing lifestyle that accompanies the
late teens and early 20s can cause dietary changes that are not always conducive to good health.
Recommendations include:
• Make a deliberate effort to keep physically active.
• Limit alcohol intake.
• Reduce the amount of fats and salt in the daily diet.
• Be careful to include foods rich in iron and calcium.
• Establish healthy eating habits that will be carried on into later life.
Pregnant women
A pregnant woman should concentrate on increasing her nutrient intake, rather than her kilojoule
intake, particularly in the first and second trimesters. In Australia, pregnant women are expected
to gain about 10–13kg during pregnancy. However, this depends on the pre-pregnancy weight of
the mother.
Recommendations include:
• Not ‘crash dieting’, as this can have a negative impact on the baby.
• Not ‘eating for two’, as this will lead to unnecessary weight gain. A healthy pregnancy only requires about an extra 850–1,100 kilojoules a day during the second and third trimester, which is equivalent to a glass of milk or a sandwich.
• Concentrate on diet quality rather than quantity.
• Accommodate cravings, but don’t let them replace more nutritious foods.

• Nutrients for which there are increased requirements during pregnancy include folate, iron
and iodine. Iron supplements are often advised, but don’t take them unless your doctor
recommends them. Folate is important three months before and in the first trimester of
pregnancy to avoid neural tube defects (like spina bifida) in the baby. All women of
childbearing age should eat high folate foods or take a folate supplement (remember to
talk to your doctor first).
• The recommended intake of calcium does not specifically increase during pregnancy. It is however, very important that pregnant women do meet calcium requirements during pregnancy.
• No one knows the safe limit of alcohol consumption during pregnancy, recommendations are to not drink at all.
• Being physically active has many benefits. If you are active and fit and are experiencing a normal pregnancy, you can remain physically active during your pregnancy. Otherwise, consult your doctor for advice.
• Drink plenty of fluids.
• Do not smoke – both direct and passive smoking are associated with growth retardation,
increased risk of spontaneous abortion, stillbirths, placental complications and low birth
weight.
Breastfeeding mothers
Breastfeeding mothers need a significant amount of extra energy to cope with the demands of breastfeeding. This extra energy should come in the form of nutrient-dense foods to assist in meeting the extra nutrient requirements that also occur when breastfeeding.
Recommendations include:
• Eat enough food – breastfeeding burns through extra kilojoules.
• Eat foods that are nutrient dense – especially those foods that are rich in folate, iodine, zinc and calcium.
• Eat and drink regularly – breastfeeding may increase the risk of dehydration and cause
constipation.
Menopausal women
Thinning of the bones is common in postmenopausal women because of hormone-related changes.
Recommendations include:

• Eat foods rich in calcium – such as milk or, if necessary, take calcium supplements as prescribed by a doctor.
• Weight-bearing exercises – such as walking or weight training can strengthen bones and help maintain a healthy body weight.
• A high fibre, low fat and low salt diet – a diet high in phytoestrogens has been found to reduce many symptoms of menopause, such as hot flushes. Good food sources include soy products (tofu, soymilk), chickpeas, flax seeds, lentils, cracked wheat and barley.
• A variety of wholegrain, nutrient-dense food – whole grains, legumes and soy-based foods (such as tofu, soy and linseed cereals), fruits and vegetables, and low fat dairy products.
Older people
Many people eat less as they get older – this can make it harder to make sure your diet has enough variety to include all the nutrition you need.
Recommendations include:
• Be as active as possible to encourage your appetite and maintain muscle mass.
• Remain healthy with well-balanced eating and regular exercise.
• Eat foods that are nutrient dense rather than energy dense including eggs, lean meats, fish, liver, low fat dairy foods, nuts and seeds, legumes, fruit and vegetables, wholegrain breads and cereals.
• If possible, try to spend some time outside each day to boost your vitamin D synthesis for healthy bones.
• Limit foods that are high in energy and low in nutrients such as cakes, sweet biscuits and soft drinks.
• Choose foods that are naturally high in fibre to encourage bowel health.
• Limit the use of table salt, especially during cooking.

• Choose from a wide variety of foods and drink adequate fluids.
• Share mealtimes with family and friends.
.

Diet can play a central role in the control and prevention of some medical conditions such as Overweight, Diabetes and Cardiovascular Diseases.
Follow the links below to find nutritional information to help in preventing or living with such illnesses.

Nutrition for School Children-Introduction to Nutrition

Introduction to Nutrition


Introduction to nutrition

Nutrition is defined as the processes by which an animal or plant takes in and utilises food substances. Essential nutrients include protein, carbohydrate, fat, vitamins, minerals and electrolytes. Normally, 85% of daily energy use is from fat and carbohydrates and 15% from protein. In humans, nutrition is mainly achieved through the process of putting foods into our mouths, chewing and swallowing it. The required amounts of the essential nutrients differ by age and the state of the body, for example: physical activity, diseases present (e.g. prostate cancer, breast cancer or weakened bones – known as osteoporosis), medications, pregnancy and lactation.


Why is nutrition important?

Nutrition is essential for growth and development, health and wellbeing. Eating a healthy diet contributes to preventing future illness and improving quality and length of life. Your nutritional status is the state of your health as determined by what you eat. There are several ways of assessing nutritional status, including anthropometric (i.e. physical body measurement), food intake and biochemical measurement. 
Your body mass index (BMI) is a good indicator of your nutritional status. It takes into account your weight and height, and correlates well with total body fat expressed as a percentage of body weight. The correlation depends on age, with the highest correlation seen in ages 26–55 years and the lowest in the young and the elderly. If you take your weight in kilograms and divide it by your height in metres squared, the figure you obtain is your BMI.
BMI 
___weight (kg)___
height x height (m2)
High values indicate excessive fat stores and low values indicate insufficient fat stores. Your BMI can therefore be used as a diagnostic tool for both over-nutrition and under-nutrition. If your BMI is between 25.0 and 29.9 you are classisfied as overweight. If it is above 30.0, you are classified as obese. The healthy BMI range is 18.5–24.9. However, the BMI is best used together with waist circumference.
 Body Mass Index (BMI) Calculator
 Enter your height and weight below to find out your BMI.
 
 
    
 
 What does this mean?
This information will be collected for educational purposes, however it will remain anonymous.
BMI calculations will overestimate the amount of body fat for:
  • Body builders;
  • Some high performance athletes;
  • Pregnant women.
BMI calculations will underestimate the amount of body fat for:
  • The elderly;
  • People with a physical disability who are unable to walk and may have muscle wasting.
BMI is not the best measure of weight and health risk. A person's waist circumference is a better predictor of health risk than BMI.
Body mass index  For more information, see Body Mass Index (BMI).

BMI and children

The healthy weight range for adults of a BMI of 20 to 25 is not a suitable measure for children.
For adults who have stopped growing, an increase in BMI is usually caused by an increase in body fat. But as children grow, their amount of body fat changes and so will their BMI. For example, BMI usually decreases during the preschool years and then increases into adulthood.
For this reason, a BMI calculation for a child or an adolescent must be compared against age and gender percentile charts. These charts should be used only by health professionals such as your general practitioner, child health nurse, or dietitian.

Body fat distribution and health risk

NutritionA person's waist circumference is a better predictor of health risk than BMI. Having fat around the abdomen or a 'pot belly', regardless of your body size, means you are more likely to develop certain obesity-related health conditions. Fat predominantly deposited around the hips and buttocks doesn't appear to have the same risk. Men, in particular, often deposit weight in the waist region.
Studies have shown that the distribution of body fat is associated with an increased prevalence of diabetes, hypertension, high cholesterol and cardiovascular disease.
Generally, the association between health risks and body fat distribution is as follows:
  • Least risk – slim (no pot belly);
  • Moderate risk – overweight with no pot belly;
  • Moderate to high risk – slim with pot belly;
  • High risk – overweight with pot belly.

Waist circumference and health risks

Waist circumference can be used to indicate health risk.
For men:
  • 94 cm or more – increased risk;
  • 102 cm or more – substantially increased risk.
For women:
  • 80 cm or more – increased risk;
  • 88 cm or more – substantially increased risk.
Being physically active, avoiding smoking and eating unsaturated fat instead of saturated fat have been shown to decrease the risk of developing abdominal obesity.
When there is an imbalance between your nutrient requirements and your intake, malnutrition sets in. There are two forms of malnutrition – under-nutrition and over-nutrition. Over-nutrition is common in many developed countries, including Australia.
Waist circumference  For more information, see Waist Circumference (WC).


Associated health conditions

Dietary factors are associated with some leading causes of death, such as:


Essential nutrient requirements

Nutrients can be described as the chemical components of food and can be classified into six broad groups: carbohydrates, proteins, fats, vitamins, minerals and water. Water is not technically a nutrient, but it is essential for the utilisation of nutrients. Nutrients perform various functions in our bodies, including energy provision and maintaining vital processes such as digestion, breathing, growth and development.

Energy balance
Your energy requirement depends on your age, size and activity level. If your energy intake equals the amount of energy you expend, then you are in energy balance. If your intake exceeds your expenditure, the excess energy is converted to body fat and you gain weight. On the other hand, if your intake is less than your expenditure, your body uses up fat stores and you lose weight. Therefore, for weight to remain stable, the total amount of calories that are consumed must not exceed the total that is used up through metabolic processes (e.g. exercising, sweating, breathing). Energy intake must match energy output. The average energy intake is about 2800 kcal/day for men and 1800 kcal/day for women, although this varies with body size and activity level.
Calorie Counter
Calculate your daily calorie intake and compare it to your recommended daily intake.


Click here to complete the Calorie Counter

Carbohydrates
Carbohydrates can be classified as monosaccharide (e.g. glucose, fructose, galactose), disaccharide (e.g. sucrose, lactose, maltose) and polysaccharide (e.g. starch, fibre). Carbohydrates must be reduced to the simplest form of glucose (through digestion) before your body can make use of them. Carbohydrates should make up at least 55% of your total energy intake. The brain is a special part of the body that depends primarily on glucose for its energy and requires about 100 g/day of glucose for fuel. In some situations, the body can compensate for decreased levels of carbohydrates by using alternative energy pathways such as burning fatty acids.

Protein
Protein is important for the production, maintenance and repair of tissues in the body. When energy intake is insufficient, protein intake must be raised. This is because ingested proteins are preferentially directed towards glucose (sugar) synthesis and oxidation. The tissues and organs in the body are made up of protein and protein compounds. Enzymes (biological catalysts), antibodies and hormones also consist of protein. The building blocks of protein are called amino acids. The body can make all of the 20 amino acids except eight, which are termed essential amino acids. These are isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine. Histidine is essential only for infants. The number and nature of amino acids present in a particular protein determines that protein's characteristics.
For adults, the recommended dietary allowance of protein is about 0.75 g/kg body weight per day. Animal products tend to have the highest amount of proteins, followed by legumes (beans), cereals (rice, wheat, corn) and roots. Animal protein (from meat, eggs, fish, milk) contains all the essential amino acids and is normally referred to as 'complete' or 'high biological value' protein. Protein derived from plants lack one or two essential amino acids. However, a good combination of plant-based protein can be of equal value to animal protein. For example, legumes lack methionine but have adequate amounts of lysine. Cereals, on the other hand, lack lysine but have a lot of methionine. Therefore, a mixture of rice and beans will supply all the essential amino acids.
Excess protein cannot be stored in the body, so we need to consume protein daily. Consuming too much protein is not recommended because it promotes increased calcium excretion through urine, which increases the risk of developing osteoporosis. Additionally, too much protein intake may lead to a greater concentration of the amino acid homocysteine in the blood, and the subsequent conversion to thiolactone. Thiolactone is associated with increased levels of atherosclerosis and endothelial damage.

Fats and oils
NutritionMost of the fats we consume occur in foods as triglycerides. A triglyceride is comprised of three fatty acid molecules attached to a glycerol molecule. Fatty acids are made up of carbon and hydrogen atoms and can be either saturated or unsaturated. Saturated fatty acids (SFA) have the maximum number of hydrogen atoms attached to the carbon chain, while unsaturated fatty acids have less than the required hydrogen atoms. For example, monounsaturated fatty acids (e.g. oleic acid) have two hydrogen atoms missing. Monounsaturated fats are found mainly in nuts, avocados, olive oil, canola oil, grapeseed oil, peanut oil, flaxseed oil, sesame oil, corn oil, safflower oil, sunflower oil, etc.
Polyunsaturated fatty acids (PUFA) have more than two hydrogen atoms missing (e.g. linoleic acid and linolenic acid). Linoleic and linolenic acids are regarded as essential fatty acids (EFAs) because the body cannot make them. There are two categories of EFAs: omega-3 and omega-6. The number that comes after "omega-" represents the position of the first double bond, counting from the terminal methyl group on the molecule. Omega-3 fatty acids are derived from linolenic acid and omega-6 from linoleic acid. Alpha linolenic acid (ALA) is converted into eicosapentaenoic acid (EPA), and later into docosahexaenoic acid (DHA) in the body. Sources  of omega-3 fats include salmon, mackerel, sardines, anchovies, tuna, flaxseed oil, walnuts, etc. Sources of omega-6 fats include palm oil, soybean oil, canola oil, sunflower oil, nuts, etc. Evidence from research indicates that omega-3 fatty acids reduce inflammation and help prevent certain chronic diseases such as heart disease and arthritis. Omega-3 fatty acids are highly concentrated in the brain and appear to be crucial to brain function as well as normal growth and development. Infants who do not get enough omega-3 fatty acids from their mothers during pregnancy are at risk of mental impairment. 
Generally, saturated fatty acids raise blood cholesterol levels, whereas unsaturated fatty acids lower them. Saturated fats are found in foods such as butter, meat and dairy fats. Trans fats are artificially created during food processing. In the body, trans fats act in a similar way to saturated fats and may raise cholesterol levels. These fats are considered to be harmful to your health. Trans fats are found mainly in deep-fried fast foods and processed foods made with margarine.
Fats are a concentrated and rich source of energy. It is recommended that your total fat intake is no more than 30% of your energy (calorie/kilojoule) intake. Polyunsaturated fat should be less than 10% of energy, and saturated fat and trans fat together should be less than 10%. The rest of your fat intake should consist of monounsaturated fat.

Vitamins
Vitamins constitute a group of nutrients that are needed in small quantities. Like amino and fatty acids, most vitamins cannot be made in the body and must be obtained from dietary sources. Only vitamin D can be manufactured by the body. Essential vitamins are grouped into two families: water soluble and fat soluble. Water soluble vitamins can dissolve in water (thiamine, riboflavin, niacin, vitamin C, folic acid). These cannot be stored by the body and need to be consumed every day. Fat soluble vitamins can dissolve in a fat medium (vitamins A, D, E, K). These are taken into our bodies when we consume fat-containing foods. Vitamins are needed for various reasons, including the formation of hormones and blood cells. They generally act as coenzymes. An inadequate supply of vitamins in our diet leads to the development of diseases.
  • Vitamin A: Derived from carotene, vitamin A affects vision, reproduction, and the formation and maintenance of skin, mucous membranes, bones and teeth. Deficiency results in night blindness (difficulty in adapting to darkness). The body obtains vitamin A from either carotene (vitamin A precursor) or by absorbing ready-made vitamin A from plant-eating organisms. Carotene is found in dark green leafy vegetables and yellow-orange fruit/vegetables. Pre formed vitamin A is found in milk, butter, cheese, egg yolk, liver, and fish-liver oil.
  • Vitamin B complex: The vitamin B complex is a mixture of eight essential vitamins necessary to enhance immune and nervous system function, and promote cell growth and division. Pregnant or lactating women, alcoholics and the elderly are more likely to suffer from vitamin B deficiency.
  • Vitamin B1 (thiamine): Thiamine, or vitamin B1, acts as a catalyst in carbohydrate metabolism. Thiamine deficiency causes beriberi, a vitamin deficiency disorder characterised by muscular weakness, swelling of the heart and leg cramps. In severe cases, beriberi may lead to heart failure and death. The richest dietary sources of thiamine are pork, organ meats (liver, heart, and kidney), brewer's yeast, lean meats, eggs, leafy green vegetables, whole or enriched cereals, wheat germ, berries, nuts, and legumes.
  • Vitamin B2 (riboflavin): Riboflavin, or vitamin B2, acts as a coenzyme in the metabolism of carbohydrates, fats, and respiratory proteins. The best sources of riboflavin are liver, milk, meat, dark green vegetables, whole grain and enriched cereals, pasta, bread and mushrooms.
  • Vitamin B6 (pyroxidine): Pyridoxine, or vitamin B6, is necessary for the absorption and metabolism of amino acids. It also plays a role in the body's use of fats and in the formation of red blood cells. The best sources of pyridoxine are whole grains, cereals, bread, liver, avocados, spinach, green beans and bananas.
  • Folic acid (vitamin B9 or folacin): Folic acid is a coenzyme needed for forming body protein and haemoglobin. Folic acid deficiency is associated with neural tube defects. Dietary sources are organ meats, leafy green vegetables, legumes, nuts, whole grains and brewer's yeast. Folic acid is lost in foods stored at room temperature and during cooking.

Minerals
Minerals are essential, acting as cofactors of enzymes (i.e. enzymes would not exist or function without minerals). Some of the minerals necessary for health are:
  • Calcium: Calcium is a very important mineral in the diet, especially for women at menopause. The major function of calcium is to build and help maintain strong bones. It can stop the onset of osteoporosis and reduce bone loss and fragility. It is involved in blood clotting. Calcium deficiency can develop when there is a lack of vitamin D.
  • Iron: Iron in food exists as haem and non-haem iron. Haem iron, found in red meat, is relatively well (20–30%) absorbed. Non-haem iron, found mostly in cereals, pulses, certain vegetables (e.g. spinach) and eggs, is generally less well absorbed. Non-haem iron absorption depends on other factors in the diet. For example, vitamin C and animal protein enhance non-haem iron absorption, while tea, coffee and phytates inhibit it.
  • Zinc: Zinc represents only 0.003% of the human body, but is essential for synthesising protein, DNA and RNA. It is required for growth in all stages of life. Sources include meats, oysters and other seafood, milk, and egg yolk.

Calcium Intake Calculator

How much calcium do you consume?
Calcium calculator Calcium is found in many foods, in particular dairy products and to a lesser degree bony fish, nuts and legumes, fruit and vegetables. It plays an important role in building and maintaining healthy bones and teeth.
Individuals need to consume sufficient amounts of calcium throughout their lifespan.  Calcium requirements increase throughout childhood, peak during puberty, then stabilise until an individual is approximately 50 years old, when bone mass deteriorates and more calcium is required.

Water
For adults, 1–1.5 mL water per kcal of energy expenditure is usually sufficient to allow for normal changes in physical activity, sweating, and dietary solute load. Water losses consist of 50–100 mL/day through faeces (stools), 500–1000 mL/day by evaporation, and approximately 1000 mL/day through urine. If external losses increase, we must increase the amount of water we ingest. In special circumstances such as diarrhoea and vomiting, water requirements further increase.


Balanced diet

Virtual Medical Centre Video

 It is critical that nutrients in our body are available in sufficient amounts and in the right proportions. This can be achieved by eating a balanced diet. We must eat a variety of foods, since different foods contain different nutrients in varying amounts. In stressing the importance of variety in our diet, Nutrition Australia encourages all Australians to ensure that their daily diet includes 30 individual foods. This may appear impossible at first thought, but in reality can easily be attained by eating typical diets based on carefully selected foods. Food selection based on the 'Healthy Eating Pyramid' can assist you in planning your meals for a balanced and healthy diet.
A healthy diet consists mainly of plant foods (e.g. fruits and vegetables, potatoes, cereals, etc.) and moderate amounts of animal products (e.g. milk, fish, lean red meat and poultry). Fats and oils should normally provide less than 30% of our energy, and less than 10% of this should be saturated fat. Lean red meat, poultry and fish, eggs and dairy foods are rich sources of animal protein. Dairy foods, apart from supplying quality protein, are good sources of calcium. Good vegetable sources of protein include legumes (e.g. peanuts, lentils, kidney beans), soya products (e.g. tofu), grains, nuts and seeds.


Healthy eating pyramid

The food pyramid is a simple practical guide to selecting varied foods for meals. The Australian Nutrition Foundation Inc. (Nutrition Australia) has developed its own food pyramid. The rationale behind the food pyramid emphasises the need to include generous amounts of plant-based foods (cereals, legumes, fruits and vegetables) and moderate amounts of animal products (meat, fish, milk, eggs) in our diets. Furthermore, our diet should contain only small amounts of energy-dense foods (e.g. sugar, fats and oils). The base of the pyramid (plant-based foods) is broad, and the top (animal products) is narrow. Eating according to the structure of the food pyramid ensures we consume a healthy diet. With care the food pyramid can also assist vegetarians and vegans to consume a nutritionally balanced diet, although some people will require dietary supplements (e.g. vegans will require vitamin B12).
Food pyramid


Glycaemic index and glycaemic load

Carbohydrates should make up at least 55% of our total daily energy intake. The quality and quantity of these carbohydrates are important in blood sugar and appetite control. After you consume carbohydrate-containing foods, your pancreas secretes insulin to break the carbohydrates down into their building blocks. Insulin acts to lower blood glucose levels. When your blood glucose levels decrease to a particular level, your brain is sent a signal and you become hungry again.
Even though different foods may contain the same amounts of carbohydrate, their effects on blood glucose control may be very different. This has lead to the development of measures such as the glycaemic index (GI) and glycaemic load (GL) of a food product. The concept of GI was formulated by Jenkins and colleagues in 1984. They found that blood glucose response to carbohydrate foods is independent of the amount of carbohydrates they contain. The limitation of the GI lies in the difficulty of translating the concept into practice, since the glycaemic effect of foods is not constant and can vary depending on the way the food is cooked.
Low GI and GL foods have been shown to be associated with health advantages such as decreased blood sugar levels. Foods with a low GI (less than 55) cause a slower and lower rise in blood glucose levels. These include breads such as mixed-grain and oat breads, barley, pasta, noodles, beans, sweet potatoes, green peas and milk. Foods with a high GI (greater than 70) cause a faster and higher rise in blood glucose levels. High GI foods include white bread, steamed white rice and chips.
By incorporating low GI foods into your diet, you will bring down the average GI of your meal, have a lower, slower blood sugar response to the meal and feel 'full' for longer.  By consuming low GI foods, you are more likely to be satisfied and feel full for longer periods of time. This helps you to maintain a healthy weight and avoid diseases such as heart disease, diabetes and some cancers. 
Glycaemic index  For more information, see Glycaemic Index (GI) and Glycaemic Load (GL).


Tips for healthy eating

Some tips for maintaining a healthy diet and incorporating the GI index into your daily routine include:
  • Follow the Dietary Guidelines for Australians and try to incorporate a variety of foods into your eating plan.
  • Try to use low GI foods instead of high GI foods when possible.
  • Try to have one low GI food at each meal.


More information

Nutrition For more information on nutrition, including information on types and composition of food, nutrition and people, conditions related to nutrition, and diets and recipes, as well as some useful videos and tools, see Nutrition. 

Article kindly reviewed by:

The DAA WA Oncology Interest Group
and
Food4Health (Helen Baker Dietitian-APD)

Reference

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  5. NSW Health, Nutrition & Pain, Community Information Series, Hunter Integrated Pain Service; 2005.
  6. Nutrition Australia. Healthy Eating Pyramid. Australia: Retrieved from: www.nutritionaustralia.org, 1999.
  7. Augustin L, Franceschi S, Jenkins D, et al. Glycemic index in chronic disease: a review. European Journal of Clinical Nutrition. 2002; 56: 1049-71.

Monday, August 16, 2010

Glycaemic Index and the carbohydrate connection.

Click on the link to find out about carbohydrates and what the GI Index is all about.
What is the glycaemic index?










What role does the Pancreas play in regulating glucose in our blood?

Don't forget to visit some of the links on the right hand-side to explore more about nutrition. There are some fun games and quiz's you can do!

Thanks,
Mrs Kreis

Friday, July 30, 2010

6 food Nutrients, food plate, dietary pyramid




Australian Guide to Healthy Eating.

FOOD GROUP
Bread & Cereals

NUTRIENTS SUPPLIED
Fibre, energy, vitamins (esp B1), iron and calcium in wholegrain products

DAILY REQUIREMENT
At least four servings daily. Wholegrain products are preferred eg: 1 serving = 1 slice of bread

FOOD GROUP
Fruit and Vegetables

 NUTRIENTS SUPPLIED
Fibre, vitamins (esp C), minerals, water, carbohydrate for energy, 

 DAILY REQUIREMENT 
At least four servings daily. Raw, cooked or juice.

 FOOD GROUP 
Meat & Meat Alternative

 NUTRIENTS SUPPLIED 
Protein, energy and vitamins and minerals (esp calcium and iron)

DAILY REQUIREMENT
One to two servings daily. 75-100g meat, chicken or fish or 1 cup cooked beans or peas

 FOOD GROUP  
Milk & Dairy Foods

NUTRIENTS SUPPLIED
Protein, energy and vitamins and minerals (esp. calcium)

 DAILY REQUIREMENT
600ml daily or 200ml yoghurt or 3cm cube of cheese

FOOD GROUP  
Butter and Table Margarine

 NUTRIENTS SUPPLIED
Energy, essential fatty acids and vitamins (esp A and D)

 DAILY REQUIREMENT
1 Tablespoon of butter or margarine or 2 tablespoons of cream daily.

Find out more about Nutrients at the below link.

Nutrients for Healthy Kids

 

Homework:

Re-examine your 3 day food diary and identify those needs that fit into the 6 food nutrients and discuss whether they met the Australian Dietary Guidelines.

You can access the guidelines at the link below if you need to refresh your memory.

Australian Dietary Guidelines link

 You can also make a brief comment  here if you think your diet needs improving.

What types of food could you add or incorporate into your diet to make it a healthy choice?

Thanks.