Nutrients
|
Functions |
|
Sources |
|
PROTEIN |
Facilitates growth & repair of all tissues.
Aids in blood formation & production of
antibodies against infection |
|
Poultry, meat, fish, eggs, milk & milk
products, peas, soya beans, dried beans and
nuts |
|
|
|
FAT |
Keeps the body warm and acts as an
insulator. Provides energy for movement |
|
Butter, margarine, cream, nuts |
|
|
|
CARBOHYDRATE |
Provides energy for movement |
|
Rice, bread, cereals, noodles, potatoes,
confectionary products |
|
|
|
CALCIUM |
Aids in building and strengthening of bones
and teeth, clotting of blood and
coordination of muscles and nerves |
|
Milk, eggs, cheese, dark green leafy
vegetables, mustard green, kale |
|
|
|
IRON |
Works with protein in the formation of
haemoglobin |
|
Red lean meat, lamb, beef, liver, heart,
eggs, sardines, green leafy vegetables,
prunes, fortified cereals, bread |
|
|
|
IODINE |
Aids in utilisation of energy by the body |
|
Seafood & seaweed |
|
|
|
MAGNESIUM |
Assists in breakdown and absorption of food
especially protein. Normal functioning of
nervous and muscular systems |
|
Milk, marmite, nuts, whole-grain cereals,
dark green vegetables |
|
|
|
PHOSPHOROUS |
Works with calcium to build strong bones and
teeth. Helps in metabolism |
|
Almost all foods |
|
|
|
POTASSIUM |
Potassium and sodium in balance are
essential to life. Between them they help
maintain and regulate the body fluids |
|
All food, especially vegetables |
|
|
|
SODIUM |
Maintaining water balance of the body fluids
is essential for muscle and nerve activities |
|
Table salt, all cured meat, milk, bread,
butter |
|
|
VITAMIN A
|
Maintains healthy skin, keeps mucous
membranes firm. Protects against infection
and sunburn. Promotes good eye-sight,
prevents night blindness |
|
Milk, cheese, dark green vegetables, liver,
cod liver oil, carrots, pumpkin, butter,
papayas, mangoes |
|
|
|
VITAMIN B1 |
Aids in promoting normal appetite &
digestion. Maintains healthy nervous system
and prevents irritability |
|
Meat, fish, poultry, eggs, cereal, marmite,
green leafy vegetables, yeast, wheat-germ
|
|
|
|
VITAMIN B2 |
Aids in absorption of nutrients. Maintains
healthy skin, tongue and lips |
|
Fish, poultry, eggs, milk, marmite, green
leafy vegetables, liver, kidney |
|
|
VITAMIN C
|
Maintains healthy bones, teeth & blood
vessels. Aids in the development of tissue
between cells. Promotes healing of wounds
and broken bones |
|
Oranges, limes, grapefruits, lemons, green
peppers, water-cress, spinach, chillies,
cauliflower, tomatoes, melons, guavas,
lettuce |
|
|
|
VITAMIN D |
Aids in strengthening of bones and teeth.
Keep muscles supple |
|
Tuna, sardines, eggs, butter, margarine,
sunlight, animal fats |
|
|
|
VITAMIN E |
Aids in the formation of red blood cells.
Protects cell membranes from deterioration
caused by the burning of fats |
|
Vegetable fats, corn oil, soya beans,
peanuts, coconut, whole grain cereals |
|
|
K
|
Helps blood to clot efficiently (not too
much, not too little) |
|
Kale, spinach, dark green vegetables |
Children and young athletes

Children who participate in high-level sports need a
diet that will support this intense training.
Insufficient energy and nutrient intakes may cause
growth and maturation may be delayed.
A healthy child’s diet should provide adequate
energy and nutrients to support normal growth as
well as the increased energy needs for training.
Children’s dietary needs differ from those of
adults. Fluid, for example, is a specific challenge
for children as they do not tolerate extreme
temperatures well and produce less sweat. When they
reach adolescence, children are faced with
additional challenges that include sexual
maturation, change in body compositions, rapid
growth, coach, parent and peer pressure, scholastic
achievement and social acceptance.
During puberty, girls gain more body fat than boys
(due to the laying down of energy for pregnancy and
lactation), whereas boys gain twice as much muscle
mass. This causes distress among many teenage girls,
resulting in distorted body images, dieting and, in
some cases, the development of eating disorders.
Boys, on the other hand, want to look more masculine
and may use nutritional supplements to achieve this.
It is thus crucial that parents, coaches
and sports physicians co-operate in monitoring the
child’s development to detect problems early on and
to establish lifelong healthy eating patterns.

Energy
The energy needs of healthy, growing children vary
depending on their age, physical activity level and
sex. It is thus crucial that a child’s needs be
worked out on a individual basis.
Adult values should also not be used, as they may
underestimate the energy requirements of children
who are less metabolically and mechanically
efficient, therefore needing more energy for their
weight and height. Children also need more energy
and growth for maturation. The estimated Energy
Requirements (EER) and Physical Activity Levels
(PAL) can be used as broad guidelines.
Protein
Protein requirements are increased during childhood
and adolescence to support growth and the additional
demands of exercise and developing muscle mass.
Children and adolescents require more protein than
adults because of the extra protein required for
growth. Protein is also required for gains in lean
body mass and to compensate for muscle regeneration.
However, there is a limit to the amount of protein
than the muscle can use. It is also important to
have sufficient carbohydrate together with the
protein, because it provides the necessary energy to
fuel the work that the muscle to stimulate it to
grow.
Protein intake should make up to 15-20% of the total
energy consumed and to up to 2g/kg body weight in
male teenage athletes. Children likely to be at risk
for inadequate protein intake include strict
vegetarians or vegans, children with multiple food
allergies or those who have limited access to food,
or who follow very high carbohydrate diets.
Micronutrients
Vitamin and mineral supplementation should not be
necessary if the child meets the higher requirements
and consumes a varied diet with nutrient-dense food
choices. Iron, calcium and zinc intake is of great
importance, especially during periods of rapid
growth.
An iron deficiency can follow periods of rapid
growth, impacting negatively on sporting
performance. In boys the gain is muscle mass is
accompanied by an increase in blood volume and in
girls iron is lost monthly due to menstruation.
Adolescents, who restrict their food intake because
they think they are fat, often suffer from
iron-deficiency anaemia.
Calcium requirements increase substantially during
adolescence to meet the demands of bone growth and
to achieve a good bone mass.
Zinc is also essential to growth, but the retention
of zinc increases during growth spurts, leading to
more efficient use of dietary sources.
Carbohydrates
Children older than two should have a daily fibre
intake equal to their age plus 5g. Good sources of
fibre include high-fibre cereals, wholegrain breads
and crackers, oats porridge, legumes, fruit and
vegetables.
Fluids
Drinking is important to replace fluid losses and
young athletes often begin training after school,
when they are already dehydrated. Fluids can also
provide energy in the form of carbohydrates. Sports
drinks provide both carbohydrates and fluid, but so
does fruit juice (preferably diluted by 50%),
diluted cordial or a carbohydrate powder added to
water.
Cutting calories
When energy and nutrient intakes are insufficient in
teenage girls, menarche (onset of menstruation) may
be delayed. This might lead to menstrual
dysfunction, resulting in low peak bone density.
This is of great concern in aesthetic sport like
gymnastics and ballet, where young athletes often
severely restrict their energy intake to achieve
lower body weights.
In boys and girls total catch-up growth may be
compromised if the delay in maturation is severe. In
addition, immature bones are more susceptible to
stress injuries.
Instead of cutting calorie intake, parents might
want to look at better snack choices and decreasing
time spent watching TV. There is a very close
correlation between the time spent watching TV and
weight gain. Not only is this inactive time, but the
advertising of fast foods and inappropriate snacks
encourages poor food choices.
Tooth decay
Tooth decay is accelerated by two conditions: sticky
carbohydrates that stick to tooth surfaces for a
long time; and frequent exposure of tooth surface to
sugar. Therefore, sticky sweets are more likely to
be harmful than a sports drink, because, while
providing the same amount of sugar, the drink is
less likely to stick to the teeth for long. If
eating or drinking sugary foods and beverages
between meals, it is important to brush, floss and
rinse the mouth afterward.
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