Fiji National University

Document Sample
Fiji National University Powered By Docstoc
       Weight and Height
Many changes occur in the time between
birth and the attainment of maturity
Body weight increases approximately
twentyfold and height threefold
During childhood (two to ten years) the
rate of increase in weight and height
occurs at a rate of about 2 kg to 3 kg and
5 cm to 6 cm per year
At adolescence there is a mark increase in
both gain in weight and height referred to
as adolescent growth spurt
On average the spurt in height begins at ten to
eleven years in girls and at twelve to thirteen years
in boys and usually lasts for two to 2.5 years
Growth spurt can vary widely in individuals, its
duration is fairly uniform in boys
On average gain about 20 cm in height and 20 kg
in weight while girls gain around 16 cm in height
and 16 kg in weight
The peak velocity for weight gain tends to occur
about three months later than that for height
In girls, the onset of menstruation (menarche)
generally occurs after the peak in height velocity,
while in boys the development of secondary
sexual characteristics is much less closely related
to the adolescent growth spurt
 The different organs and tissues of the body
do not all follow the same pattern
Almost all of the postnatal growth in the brain
occurs in the first five years of life
Virtually there is no growth in the
reproductive organs until the teens
The early rapid growth of the brain and head
is one of the reasons why malnutrition in
early childhood is particularly serious
The differences in growth rate of the various
parts of the body are also evident in the
changes in body proportions that occur with
The changes that occur in body composition are
less obvious
At birth, the lean tissues contain both more water
and less protein than later in life
The body as a whole contains less fat
In the full-term infant, the body content is around
15% and differs more with gestational age than
with gender
During childhood, girls tend to have slightly more
fat than boys, but the mark difference in body
composition with gender which are seen in adults
do not emerge until adolescence
Adolescence is also accompanied by major
differences in the rate and amount of lean tissue
Boys show a rapid and sustained spurt in lean
weight and only modest increase in body fat
While girls experience a smaller gain in lean
weight and a larger gain in body fat
During the second decade of life, boys double
their lean weight while in girls lean weight
increases by only about 50%
The end result is that fat-free weight makes up
about 85% of the total body weight of a mature
male, but only 75% of the total body weight of a
mature female
The difference in body composition is
physiological and provides mature females with an
energy reserve for demands of pregnancy and
An adequate food supply is essential for
normal growth
Children who do not have access to sufficient
food gain less weight and height than those
who are adequately fed
There are two approaches to estimating the
energy and nutrient requirements of children
The first is to observe the food intake of
healthy infants and children and the second
is to base requirements on the amounts of
nutrients accumulated in the body during
In most instances, the recommendations for
dietary intake (RDI) are based on both kinds
of information
The energy requirement for basal metabolism
and activity increases proportionately with
body size
While the energy requirement for growth is
relatively small after the first year of life
Activity is a major component of the energy
requirement and varies considerably among
It is not unusual to find among healthy
children of similar age and body size that the
energy intake of some is twice that of others
The difference in energy intake is due largely
to differences in the energy expended in
physical activity
Dietary recommendations for energy intake
are for average values only and do not apply
to all individuals of a given age group, but
merely represent an estimate of the average
needs of the group
Expressed in terms of energy per kilogram of
body weight, the average energy requirement
falls from around 300kj – 400kj per kg in the
first year to around 200kj per kg in late
Nutrient requirements also gradually increase
but not usually in relation to energy intake
The amounts of calcium and iron required for
growth are particularly high in relation to
maintenance requirements at the peak of the
adolescent growth spurt
It is also clear that during adolescence the
rate of growth and the stage of physical
maturity are more important in determining
nutrient requirements than age per se
One way of taking growth into account during
adolescence is to express the RDI for a
nutrient per cm of height
This value is likely to provide a better
estimate of an individual’s need for nutrients
         Nutrition related concern
Food refusal:
 During the early pre-school years the rate of growth is relatively slow
 compared with that during infancy
 The toddler also learns new skills and become more interested in
 activities other than eating
 Parents are often concerned by the fact that their two old refuses to
 eat much of the food that has been prepared for the family
 The behavoiur is not uncommon and many children in this age
 group accept only one or two foods for short periods of time
 This kind of behaviour is worrying to parents, it does not usually
 pose a nutritional problem and is self-limiting
 Other children of the same age may continuously demand food
 Like the previous behaviour, this may be a way of seeking attention
 rather than a sign of hunger
Iron deficiency is the most common
nutritional deficiency of early childhood
Iron deficiency may occur where:
– When young children are given large
  quantities of cow’s milk in the absence of
  foods which are good sources of iron
– When children have repeated attacks of
  gastro-enteritis or
– When children are given a vegetarian diet,
  which is high in bulk and from which iron is
  not readily absorbed
Full-term infants usually have sufficient iron
stores to meet their requirements for iron until
about six months of age
After six months, unless infants receive an infant
formula fortified with iron or adequate amounts
of foods which are good sources of iron, such as
an infant formula preparation, breakfast cereals
fortified with iron, meat or dark green leafy
The body store of iron will become exhausted,
the haemoglobin level will fall and eventually
anaemia will develop
There are several reasons why anaemia in
  early childhood is of special concern:
  Firstly, it can lead to retardation in both physical
  and mental development that may not be
  Secondly, it also appears to decrease resistance
  to infections and to increase morbidity,
  particularly in pre-school children
  Iron deficiency in this age group can be
  prevented breastfeeding rather thar bottle
  feeding where possible, by introducing solids at
  four to six months and by delaying the
  introduction of cow’s milk as a major drink until
  the second year of life
             Dental caries
Dental caries affect children of all ages and
socio-economic background
Once the teeth have erupted through the gum
they are vulnerable to the effects of the bacteria
present in the mouth
These bacteria are responsible for the formation
of dental plaque, for the fermentation of dietary
carbohydrates to acids and for the production of
other substances which have the potential to
degrade both tooth enamel and dentine and lead
to cavities
Sugars are the principal substrate for plaque
formation and fermentation
The potential to produce tooth decay
(cariogenicity) of a food is not simply a function
of its sugar content and the amount that is
consumed but depends on a number of other
factors including:
- frequency of use
- effects on saliva production
- time of retention on the tooth
- effects on dental plaque formation and
- a food’s ability to dissolve enamel

Obesity is defined as an
excessive deposition of adipose
tissue and is usually diagnosed
formally if a child has a body
weight that is greater than 120%
of that expected for his/her age
Children who are obese are often also tall for
their age and it is therefore important to take
height and maturity into considerationalso
In practice ‘eye balling’ is likely to lead to a
correct diagnosis
What is clear is that once established, obesity is
difficult to treat
While the prevalence of obesity appears to be
greater during the periods of most rapid growth,
that is during the first year of life and at
adolescence, it can develop at any time during
There is evidence to suggest that both infancy
and adolescence and possibly also the period of
adipose between five and seven years of age,
are particularly critical periods for the
development of obesity since obesity that begins
at these times appears to increase the risk of
persistent obesity
Regular growth monitoring during childhood
enables the early detection of excess weight
gain relative to height gain, but such monitoring
is unfortunately neither routinely practised in
most countries
In treating obesity in childhood two factors need to be
First, very low energy diets are not suitable for the
growing child as it is difficult to ensure an adequate
intake of essential nutrients when energy intake is low
Food intake, needs to be sufficient to provide an
adequate intake of essential nutrients, vitamins and
The best way to achieve this is to limit the intake of foods
most likely to be contributing to energy intake such as:
- high energy between energy snacks
- large volumes of fruit juice, fruit juice drinks, and cordial
- high fat varieties of foods such as milk, cheese, and
Second, activity levels also need to be
Obese children are often inactive by
nature and spend more time watching
television than in more active pastimes
such as swimming, cycling and ball games
Family participation in both dietary and
activity strategies is important if they are to
be effective
      Nutritional concerns at
Adolescence eating patterns:
 The hallmark of adolescence is change
 This includes change in physical
 characteristics, in psychological
 development, and in social roles and
 One important consequence of these
 changes is the assumption by
 adolescents of increasing control over
 their own eating patterns
The foods eaten will now depend not primarily on family
food patterns, but also on many other factors including
self-image, peers, the media, cultural and social
expectations in relation to body shape and size, access
to money for food and the proximity of food outlets
Consumption of snacks both between and instead of
meals is a common feature of adolescent diets
 There is concern that this kind of eating pattern cannot
meet the high nutritional requirements associated with
the adolescent growth spurt
The nutritional implication of an eating pattern is
sometimes described as ‘grazing’ depend more on what
is eaten than when or how it is eaten
The fact that adolescents have higher total
energy requirements than young adults is often
On average, adolescent energy requirements
are about 1000 kj higher per day than those of
adults and consequently there is room for the
consumption of some foods with a higher energy
Although many snacks (chocolate bars, potato
chips, crisps, cakes, pies, biscuits, and soft
drinks) may be high in fat or sugar and energy
and relatively low in nutrient content, this is not
an invariable feature of snacks
Fruit, raw vegetables, cheese, bread,
breakfast cereals, eggs, meat and fish can
all be eaten in the form of snacks that
have a high nutrient concentration
The eating of snacks (as opposed to
meals) does not necessarily constitute a
problem if a wide selection of foods is
Snacks can make a significant
contritbution not only to energy but also to
nutrient intake provided they are chosen
from a wide range of basic foods
One consequence of over-consumption of energy dense
snack foods during adolescence may be obesity
Energy intake is not the sole reason for obesity that
develops during adolescence
Other factors related to social, psychological or
physiological changes at this time also play a role eg.
Individuals who mature earlier appear to have a greater
tendency to become obese at that time
Whether this is because overnutrition leads to earlier
maturation or because the increased energy intake
associated with adolescence continues after growth has
already ceased is not clear
Whatever the reasons for the development of obesity in
adolescence, the effects on the individual are particularly
distressing at this time, and may lead to a situation in
which food and eating assume unusual importance
The fear of becoming overweight is particularly strong in
adolescent girls and dieting and other forms of weight
control behaviours are common in this age group
Attempts to lose weight, or simply to prevent weight gain,
by means of extreme diets which are in adequate or
imbalance in their energy and nutrient content,
sometimes combined with excessive physical exercise,
tend to result in the loss of more water and lean tissue
from the body than fat
Apart from their negative impact on growth and
development during adolescence, they may also have
longer-term undesirable effects on health in later life
When such behaviours continue for any length of time
they constitute an eating disorder
         Eating disorders
Eating disorders, disturb what might be referred
to as ‘normal eating’, though it needs to be
recognized that many very different eating
patterns can be regarded as ‘normal’
An eating disorder is an abnormal pattern of
eating associated with marked dissatisfaction or
distress in a person who is otherwise healthy
The principal eating disorders are anorexia
nervosa, bulimia nervosa, and binge eating
Anorexia nervosa is a psychological disturbance
most commonly seen in teenage girls and
characterized by self-starvation
There is a severe and prolonged inability or
refusal to eat although no identifiable disease is
Bulimia nervosa is a related condition commonly
affecting young women in which they engage in
cycles of binge eating alternating with food
restriction and purging
Binge-eating refers to sessions of gross over
eating, followed by purging, as an attempt to be
rid of the perceived excess of food eaten
This may be attempted by overusing laxatives
or other medications or by self-induced vomiting
Eating disorders are relatively common; they
may be minor or so extreme as to make normal
living impossible
Eating disorders have a major effect on the
quality of life of those affected
They are uniformly unhappy with their situation
Those who are close to them often feel helpless
in trying to be of assistance
Children may develop eating disorders of
various types including food fads, food refusal or
food aversion
The child may demand that food is
presented in a particular way; eg. It may
have to be on a particular plate in order for
them to eat it
They may refuse to eat anything except
meat, or perhaps they may refuse to eat
their meal unless they are arranged on a
plate exactly like their mother’s or father’s
                Food fads
Food fads seldom last long and rarely cause a
Food refusal by young children, on the other
hand, can be stressful for the parents
Children may refuse to eat and the hapless
parents, instead of simply putting the food away
and waiting until the next meal, may offer other
foods to tempt them to eat
Children soon learn that they can manipulate
their parents’ behaviour by refusing that is first
Frequently they ‘train’ their parents to give
them just what they want, even if it means
cooking special foods which are different
from those of the rest of the family
Life is made easier for parents if they
realize that that missing an occasional
meal imposes no risk to their children and
they can wait for them to be hungry and
eat at the next meal
            Food aversion
Food aversion is interesting because most of us
have some personal experience of it and it
probably has had survival value in human
Food aversion is a dislike or fear of eating a
particular food because of an unpleasant
association eg. taking medicine and orange
It is speculated that food aversion probably had
its origins in protecting mammals from poisoning
Many plants contain toxins which can produce
illness in small quantity
A long lasting aversion (negative aversion)
linking sickness with the consumption of a
particular plant would protect against further
consumption of that food
Food aversion is easily demonstrated in animals
Rats given an injection of a substance which
causes unpleasant symptoms shortly after
having eaten a food which is new to them will
develop a strong aversion to that food
            Anorexia nervosa
Anorexia nervosa is a psychological disorder, most usually
affecting teenage girls
The first recorded case was in 1684
Those affected persist in trying to lose weight even though they
are already very underweight
The term anorexia refers to lack of appetite
Temporary loss of appetite is common in illness or with
anxiety, but in anorexia nervosa, the individual determinedly
goes on trying to lose weight despite family and medical advice
No known disease is involved
Prevalence approximately one in fifty, and one in one hundred
in the most susceptible group which is teenage girls
Teenage boys and young men also may be affected but this is
often associated with substance abuse
   Eating disorders are more common in male
   homosexual and in individuals abusing alcohol
   and/ or drugs
   The incidence is increasing in sports such as
   body building, wrestling, and for jockeys where
   weight control is critical to success
   The outstanding characteristics are as follows:
1. Low body weight
2. Food avoidance and faddism
3. Excessive concern about being fat
4. Distorted perception of body size
5. Use of purging
6. Excessive exercise
 Classification of anorexia nervosa
1. Refusal to maintain body weight at or above a
   minimal normal weight for age and height
2. Intense fear of gaining weight or becoming fat
   even though underweight
3. Disturbance in the way in which one’s body
   weight or shape is experienced, undue
   influence of body weight or shape on self
   evaluation, or denial of the seriousness of the
   current low body weight
4. In pos- menarcheal females, amenorrhea i.e.
   the absence of at least three consecutive
   menstrual cycles
         Effects of anorexia nervosa

The body loses both fat and muscle so that the affected
person is thinner and weaker
Physical activity is low except for periods of exercising
Basal metabolic rate falls as much as 10% to 15% to
conserve energy
Fine downy hair may appear on the body and
menstruation ceases
Long-term problems include retardation of normal
growth, impaired fertility and osteoporosis resulting from
the failure to secrete the normal amounts of female sex
Because of the reduced food intake, deficiencies of
micronutrients such as zinc or iron may also occur
Depression often accompanies anorexia
Most of those affected recover to a
degree, but a proportion remain very thin
and a proportion retain some form of
psychological problem
        Causes of anorexia nervosa
The condition usually begins with some form of
Dieting is of course extremely common yet only
a small proportion of dieters develop anorexia
The psychology of anorexia nervosa appears to
be closely related to the obsessive-compulsive
group of behaviour
The importance of ‘desire to achieve’ in initiating
anorexia nervosa is shown by the relatively high
rates of anorexia nervosa among dancers and
gymnasts, sports in which a high, thin body is
essential for success
     Management of anorexia nervosa
Severe anorexia is a serious condition and parents of
affected children should not delay in seeking help
Early management is more likely to be successful
The longer it persists the more likely the problem is to
become difficult
Management centres on counselling is usually sought
Usually psychologist or psychiatrist is required to keep a
detailed record of behavioural events and to record at the
same time the thoughts and feelings that accompanied
those behaviour
The therapist then goes through the record together with
the patient to explore the thoughts and feelings that
prompted the behaviours
By analyzing the underlying thoughts, impressions and
beliefs, the therapist aims to reorient the thinking of the
individual to a more rational and accepting frame of mind
The aim of this therapy is to mould the underlying
psychological framework to one which will not trigger the
anorexia behaviour
 Anorexia nervosa varies widely in severity; in mildly
affected individuals counselling may be effective,
whereas for those severely affected specialist clinics or
even hospitalization may be required
Many types of treatment have been tried but none has
been markedly successful
The affected person requires intense encouragement in
order to initiate weight gain, and as weight gain is
achieved mental outlook and prognosis improve
            Bulimia nervosa
Bulimia nervosa is an eating disorder closely
related to anorexia nervosa and expressed
through a range of disturbed behaviours
In bulimia nervosa the affected person is
generally overweight to some degree and is
trying, or has tried to lose weight by restricting
food intake
Natural hunger has overcome the resolve to diet
and the person begins ‘binge eating’
This refers to eating an exceptionally large
amounts of food in a period of an hour or two
After the binge the person is likely to feel
depressed at having broken the diet, and
depressed at being unable to get their weight
down to the level they desire
In a desperate attempt to prevent the inevitable
weight gain as a consequence of overeating
they may resort to self-induced vomiting or
laxative abuse
After this event they may resolve to ‘really stick
to the diet this time’ and eat only a small amount
of food over the next day or two; hunger grows
to the point where another binge becomes
inevitable and the whole cycle is repeated
The life of the bulimia individual becomes
haphazard and unhappy, with no fixed
meal pattern, difficulties in relationships
because of stress around eating, and often
depression or other psychological
      Classification of bulimia nervosa
1.   Recurrent episodes of binge eating
2.   Recurrent inappropriate compensatory behaviour in
     order to prevent weight gain, such as self-induced
     vomiting, misuse of laxatives, diuretics, or other
     medications, fasting, or excessive exercise
3.   The binge eating and inappropriate compensatory
     behaviours both occur, on average, at least twice a
     week for three months
4.   Self-evaluation is unduly influenced by body shape and
5.   The disturbance does not occur exclusively during
     episodes of anorexia nervosa
        Effects of bulimia nervosa
1.   Depression
2.   Weakness
3.   Dehydration and acid base imbalance
4.   Erosion of tooth enamel can occur due
     to repeated contact of stomach acid with
     the teeth during self-induced vomiting
Prevalence of bulimia nervosa
Individuals who develop bulimia nervosa
are generally older than those who
develop anorexia nervosa
The condition is more common than
anorexia nervosa
      Management of bulimia nervosa
Management is based on psychological counselling,
requires a psychologist or psychiatrist
The first step is to identify the range of problems
perceived by the affected person and to help him or her
to address those problems and to gain a true perspective
of their significance
In terms of nutritional management, it is desirable first to
establish an even pattern of meals
The person needs reassurance concerning the amount
and type of food that they can eat without adding to a
perceived obesity problem
The concept of energy balance can be explained
A meal plan can be devised with low energy density,
attractive meal plan for a day with generous use of
cereals/products, vegetables and fruit
It is important that the problem of anorexia and
bulimia nervosa are recognized in the
community by parents, teachers, doctors,
dietitians and other professionals working with
young people
It is a challenging problem
The most effective approach is to educate
children in their teenage years regarding normal
body composition and the role of diet and
exercise and to assist them to have a realistic
view of their own weight
     Simple test for eating disorder
1. Do you make yourself Sick because you
     feel uncomfortably full?
2.   Do you worry you have lost Control over
     how much you eat?
3.   Have you lost more than One stone in a
     three-month period?
4.   Do you believe yourself to be Fat when
     others say you are too thin?
5.   Would you say that Food dominates your