Diet through life
© Food – a fact of life 2009
Extension
Learning objectives
• To recognise the different key stages in life.
• To understand why different amounts of energy and
nutrients are required through life.
• To describe the needs of different life stages to
maintain health.
© Food – a fact of life 2009
Energy needs change through life
Energy requirements change through life and depend
on many factors, such as:
•age;
•sex;
•body size;
•level of activity.
The amount of nutrients needed to keep the body
healthy is also different for each person.
© Food – a fact of life 2009
Key stages in life
The key stages in life include:
•pregnancy;
•infancy;
•childhood;
•adolescence;
•adulthood.
It is important to maintain good health through life.
© Food – a fact of life 2009
Pregnancy
A varied diet, providing adequate amounts of energy
and nutrients, is essential both before a woman
becomes pregnant (conception) and during
pregnancy.
The mother’s diet can influence the health of the
baby.
© Food – a fact of life 2009
Conception and early pregnancy
Being a healthy body weight is important before
pregnancy.
Being underweight can make it more difficult to
conceive. It can also make it more likely that the baby
will have a low birth weight, leading to a greater risk of
ill health.
Being overweight increases the risk of complications,
such as high blood pressure and diabetes during
pregnancy.
© Food – a fact of life 2009
Conception and early pregnancy:
folate
Folate (the natural form of folic acid found in foods) is
needed for rapid cell division and growth in the foetus
that takes place during pregnancy.
It has been shown to reduce the chance of neural
tube defects, such as spina bifida, in the unborn baby.
Foods that are good sources of folate are green leafy
vegetables, oranges, bread and fortified breakfast
cereals.
© Food – a fact of life 2009
Conception and early pregnancy:
folate
Women who are trying to become pregnant, or who
are pregnant, should take a 400 microgram (μg)
supplement of folic acid every day from the time they
stop using contraception until at least the 12th week of
pregnancy. This is because it is difficult to achieve the
extra folate needed through diet alone.
All women of child-bearing age are also advised to
consume adequate amounts of folate. This is
particularly important because it may take time for a
woman to realise that she is pregnant.
© Food – a fact of life 2009
During pregnancy
During pregnancy, a woman’s nutritional needs
increase to:
• help the growth of breasts, uterus and placenta;
• meet the needs of the growing foetus;
• lay down stores of nutrients to help the growth of the
foetus, and in the mother for lactation.
© Food – a fact of life 2009
Extra energy needs during pregnancy
During the first six months of pregnancy, most women
do not need to eat more food than normal. The body
becomes more efficient at absorbing and using
nutrients from food.
The Estimated Average Requirement (EAR) increases
during the last three months of pregnancy by an
average of 800kJ per day.
Gaining too much weight during pregnancy can raise
the mother’s blood pressure and increase her risk of
being overweight or having diabetes.
© Food – a fact of life 2009
Weight gain during pregnancy
On average, if a woman eats to satisfy her appetite,
her weight will usually increase by about 3.5kg in the
first 20 weeks, then 0.5kg a week until the end of
pregnancy.
The total weight gain will be about 12.5kg.
© Food – a fact of life 2009
Foods to avoid during pregnancy
• Too much vitamin A during early pregnancy has
been linked to birth defects. Vitamin A rich foods
include liver and liver products, such as pâté,
vitamin A supplements and fish liver oils.
• Unpasteurised dairy products, such as Brie and
Camembert, may be contaminated by Listeria,
which can cause a miscarriage or infect the baby,
so should not be consumed.
© Food – a fact of life 2009
Food to avoid during pregnancy
• Shark, swordfish and marlin. These types of fish may
contain high levels of mercury, which can harm an
unborn baby’s developing nervous system.
• Pregnant women, and those who are trying to
conceive, are advised to stop drinking alcohol.
Alcohol may damage the unborn child.
© Food – a fact of life 2009
Birth
A normal pregnancy is between 37 and 41 weeks.
On average, new-born babies weigh around 3.3kg.
Boys are approximately 300g heavier than girls.
© Food – a fact of life 2009
Infant feeding
The process of producing breast milk is called
lactation.
Breast milk provides all the energy and nutrients a
baby needs for growth and maintenance during the
first 4 to 6 months of life.
In the first three days after birth, the mother produces
a special form of breast milk called colostrum. It
contains less fat, more protein and more protective
factors than the breast milk produced later.
© Food – a fact of life 2009
Breast feeding
A mother who is breast feeding requires extra energy
and nutrients. Some of this requirement is supplied
through extra stores laid down during pregnancy, in
addition to the diet.
The extra EAR for energy during lactation is 1900kJ per
day during the first month, and later depends on how
long breast feeding is continued. There are also
increased demand for nutrients, such as calcium,
phosphorous, vitamin A and C.
© Food – a fact of life 2009
Breast milk
On average, 100g of breast milk provides:
● 289kJ energy
● 1.3g protein
● 4.1g fat
● 7.2g carbohydrate
● 34mg calcium
Breast milk provides special proteins, antibodies and
white blood cells, which help to protect the baby
against infection.
It also provides growth factors and hormones,
important for the healthy growth and development of
the baby.
© Food – a fact of life 2009
Bottle feeding
If a mother does not wish to breast feed her baby, or
finds it difficult, she can use an infant formula (also
known as ‘baby milk’) from a bottle with a teat. Infant
formulas do not provide any of the factors that help
prevent infections.
It is important to note that once a mother has started
to bottle feed her baby, it is difficult to change to
breast feeding.
The Department of Health recommends exclusive
breast feeding for the first 6 months of life.
© Food – a fact of life 2009
Weaning
After 4 to 6 months of age, milk no longer fulfils all the
baby’s needs for energy and nutrients. The baby must
be given other foods in addition to breast milk or infant
formula. This process is called weaning.
Weaning before this age is not recommended, as the
intestines and kidneys may not be able to process the
food.
© Food – a fact of life 2009
Weaning
Different foods can be used during weaning, but they
must be semi-fluid and soft, since the baby has no teeth
and cannot chew, e.g. rice, puréed vegetables and
fruit and mashed potatoes.
It is recommended that infants under 6 months should
not be given wheat or other cereals that contain the
protein gluten. This is to avoid a possible allergic
reaction to gluten, called coeliac disease.
Eggs should be cooked until both the white and yolk
are solid. Raw eggs and foods that contain raw or
partially cooked eggs should be avoided due to the risk
of food poisoning from Salmonella.
© Food – a fact of life 2009
Supplements
After the age of 6 months, infants receiving breast milk
as their main drink or receiving less than 500ml of infant
formula each day, should be given supplements of
vitamins A, C, and D in the form of liquid drops.
Between the age of 1 to 5 years, vitamins A and D
supplements should be given unless the baby receives
adequate intake and exposure to sunlight.
Cow’s milk should not be given to infants under 1 year
of age as the main drink because it does not provide
adequate nutrients for the infant.
© Food – a fact of life 2009
Childhood
The energy requirements of children increase rapidly
because they grow quickly and become more active.
This means they have a high energy requirement for
their size.
Young children do not have large stomachs to cope
with big meals. Therefore, to achieve the relatively
high energy intake for their age, foods should be
eaten as part of small and frequent meals.
© Food – a fact of life 2009
Healthy weight in childhood
Children should be encouraged to remain a healthy
weight with respect to their height. A healthy family
lifestyle can help in the weight management of
children.
© Food – a fact of life 2009
Childhood
A good supply of protein, calcium, iron, vitamin A and
D, as part of a healthy, balanced diet, is essential.
Calcium is needed for healthy tooth development,
and together with vitamin D, help develop strong
bones.
© Food – a fact of life 2009
Dental hygiene
Children should pay attention to dental hygiene and
ways to prevent dental caries.
If children choose to consume food and drinks high in
sugar occasionally, this should be done at mealtimes
and not in between meals.
Brushing teeth twice a day with a fluoride toothpaste
and using dental floss will help maintain healthy
teeth. Regular dental visits are also important.
© Food – a fact of life 2009
Foods to avoid in childhood
Nuts
• Whole or chopped nuts should not be given to
children under 5 years to avoid choking. Some
children may also be allergic to nuts.
Deep sea fish
• Shark, swordfish and marlin contain relatively high
levels of mercury, which may damage the
developing nervous system of children.
© Food – a fact of life 2009
Adolescence
Adolescence is a period of rapid growth and
development and is when puberty occurs.
The demand for energy and most nutrients are
relatively high. Boys need more protein and energy
than girls due to their later growth spurt.
A growth spurt begins around 10 years of age in girls
and 12 years in boys. In both sexes, an average of 23
cm is added to height and 20 to 26kg in weight. Before
adolescence, both girls and boys have an average of
18% body fat, during adolescence, this increases to
around 28% in girls and decreases to around 15% in
boys.
© Food – a fact of life 2009
Weight management in adolescence
Adolescents should have plenty of energy in their diet
for rapid growth. However, some adolescents tend to
eat more than they need and become overweight.
It is important to encourage an active lifestyle with a
healthy, balanced diet during this time, because good
habits practised now are likely to benefit their health
for the rest of their lives.
© Food – a fact of life 2009
Adolescence
After menstruation begins, girls need more iron than
boys to replace losses.
It is recommended that teenage girls and women
require 14.8 mg of iron each day, while adolescent
boys only need 11.3mg of iron per day, but this
reduces to 8.7 mg of iron daily for men aged 19 or
above.
Some women have very high iron requirements
because they have large menstrual losses.
© Food – a fact of life 2009
Adulthood
Nutritional requirements do not change much
between the ages of 19 to 50, except during
pregnancy and lactation.
On average, UK adults are having too much saturated
fat and salt from food, and not enough fruit and
vegetables.
A poor diet can lead to diseases such as obesity,
cardiovascular diseases, cancer and diabetes.
© Food – a fact of life 2009
A balanced diet for adults
To reduce the risk of developing these diseases, it is
important to:
•eat a balanced diet with plenty of fruit and
vegetables;
•opt for healthier fats;
•get enough dietary fibre (NSP);
•keep well hydrated;
•stay active;
•drink alcohol in moderation;
•not smoke.
© Food – a fact of life 2009
Healthy weight for adults
Adults should aim for a healthy body weight for their
height and try to keep it at that level.
The Body Mass Index (BMI) is a good indicator if a
person is underweight, overweight or a healthy weight.
To calculate BMI (kg/m2), divide weight (kg) by height
(m) x height (m).
Recommended BMI range
Underweight
less than 18.5
Normal
18.5 - less than 25
Overweight
25 - less than 30
Obese
30 - 40
Very obese
over 40
© Food – a fact of life 2009
Older adults
Requirements for energy gradually decrease after the
age of 50 as activity level falls.
Older adults is the term usually refer to people over the
age of 65.
© Food – a fact of life 2009
Older adults
Older people may eat less for different reasons,
for example:
• difficulty in chewing and swallowing;
• dental problems;
• changes in sense of smell and taste;
• difficulty in shopping, preparing and cooking food;
• living alone;
• financial problems;
• illness.
To maintain good health, it is important that older adults:
• enjoy their food;
• keep active;
• have adequate nutrient intakes.
© Food – a fact of life 2009
Healthy ageing
Older adults should adopt a healthy, balanced diet to
maintain health.
It is also important they keep hydrated by drinking
plenty of fluid. Even minor dehydration may lead to
health problems.
© Food – a fact of life 2009
Older adults
After menopause (when menstruation stops), women
lose bone strength at an increased rate. Having a
great peak bone mass (PBM) in early adulthood helps
adults to start from a higher point from which bones will
be lost during the ageing process.
As people age, osteoporosis may occur when bones
become weak, brittle and break easily. This may lead
to fractures in the wrist, back and hip.
Osteoporosis is a major problem in older people,
especially women.
© Food – a fact of life 2009
Older adults
Older adults should have plenty of calcium intake from
milk and dairy products, green leafy vegetables,
beans, pulses, and products made from white and
brown flour, which are fortified with calcium in the UK.
They should also remain active and have adequate
vitamin D from foods such as oily fish, cod liver oil and
margarine, or through the action of sunlight on the skin.
Everyone over 65 years of age is recommended to
take supplements of vitamin D.
© Food – a fact of life 2009
Review of the learning objectives
• To recognise the different key stages in life.
• To understand why different amounts of energy and
nutrients are required through life.
• To describe the needs of different life stages to
maintain health.
© Food – a fact of life 2009
For more information visit
www.foodafactoflife.org.uk
© Food – a fact of life 2009