Nutrition and health
Before food can be digested, it must first be ingested, which is the process
of taken food into the body (eating). Food is first mechanically digested by
the teeth (chewing) then chemically digested by enzymes; amylase in the
saliva, proteases and carbohydrases in the stomach and small intestines.
As the food travels through the digestive tract by peristalsis, it is
assimilated and nutrients absorbed. Waste is then egested out of the
system.
Physiology of the digestive system and nutritional
information
Food types Sources Functions in the Deficiencies and
body excess
Carbohydrates Starchy foods- Our main energy Not having
rice, pasta source which enough
Lean meats- provides fuel for carbohydrates in
chicken the body. It your diet can
Sugars helps you feel cause fatigue,
full and keeps constipation and
cholesterol in vitamin and
balance. mineral
deficiencies. Too
many carbs will
cause the body
to store the
excess as fat
which will lead
to obesity and
heart disease.
Lipids Meats- Lamb, Used for energy Not enough fats
pork stores (fat) will not provide
Avocados, Nuts, which is the body with
Oils and butters insulation and energy which
protection for can lead to
organs. It is heart attacks,
needed for fat strokes and
soluble vitamins atherosclerosis.
and making cell Too many fats
membranes. will be stored in
the body and
lead to obesity,
diabetes and
heart disease.
,Proteins Meats- beef, Needed for A diet with
lamb creation of deficient protein
Eggs, enzymes and can lead to loss
Nuts/seeds muscle growth of muscle mass
(Protein). It is and a slow
used for tissue metabolism. It
repairs, blood can also lead to
and anaemia and
neurotransmitte kwashiorkor
rs in neurons. which includes
stunted growth,
tissue oedema
and muscle
wasting. Excess
proteins will be
stored as fat so
a high protein
diet can lead to
weight gain.
Water Liquids- tea, Needed for Not enough
coffee, juices bodily fluids- water causes
Fruits and Blood, saliva dehydration,
vegetables and flushes out urine infections
urea as urine. and electrolyte
It has no and osmotic
calories or imbalances in
nutrients unless the body. It also
it is mineralised. stops enzymes
from being able
to catalyse
reactions,
leading to
hyperthermia.
Too much water
in a short time
frame can cause
water poisoning
and disrupt
brain function.
Fibre Wholegrains Needed to make Too little fibre in
Fruits- apples you feel full and the diet causes
Vegetables- keep food constipation
Aubergine moving through which in the
the digestive long term can
tract. We do not lead to IBS and
, have enzyme to bowel cancer.
digest fibre. Too much fibre
causes bloating,
gas and
constipation.
Vitamin A Liver Needed for Too little vitamin
(Retinol) Leafy greens, vision, the A in the diet can
yellow and immune system cause blindness,
orange and our xerophthalmia
vegetables reproductive and
organs. Used in keratinisation.
growth and As it is
development. processed in the
liver, too much
can cause liver
poisoning and
damage as well
as bone
thinning.
Vitamin B (1-6) Seafood Helps the body Not enough will
Dairy products convert food cause anaemia
Breakfast into energy, and too much
cereals create new will cause upset
blood cells and stomach and
aids in cell skin conditions.
functions. The
discovery of
vitamin B cured
Beri-Beri
disease.
Vitamin C Citrus fruits- Needed for A low vitamin C
(Ascorbic acid) oranges, healthy skin and intake causes
grapefruit, kiwis, building of bloodscurvy and
berries vessels. Also hyperkeratosis,
used to maintain and too much
cartilage. causes stomach
problems and
diarrhoea.
Vitamin D 2 and 3 Fish oils Needed for Too little will
(Calciferols) Red meats calcium and result in loss of
Liver phosphate bone density
Sunlight absorption. which can lead
Calcium is to osteoporosis.
needed for teeth Too much will
and bones. cause
