SKINCARE
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BODYCARE
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OPTIMAL
HEALTH
Amino acids
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Homeocysteine
High protein diets
Know your fats
Nutrition
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Vitamins & minerals
RDA vs ODI
GENERAL
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WE ARE WHAT WE EAT
How the body works l Macronutrients l Micronutrients l Water
HOW THE BODY WORKS
BASIC
DIGESTION
Mouth & oesophagus: Digestion begins in the mouth
with the grinding of food and the admixture of saliva. An enzyme in the saliva,
called Ptyalin (salivary Amylase) begins carbohydrate digestion by splitting
starches into simple sugars. The peristaltic contractions of the oesophagus help
move food to the stomach,
Stomach: The stomach acts as a temporary resevoir
for food, allowing the digestive enzymes time to work, and lies just behind
the lower ribs. Virtually nothing is absorbed through the stomach walls except
alcohol, some drugs and medications and water.
In the stomach, food is further broken apart, and thoroughly mixed with a gastric
acid (Hydrochloric acid) and digestive enzymes that break down proteins. The
acid itself does not break down food molecules, rather, the acid provides an
optimum pH for the reaction of the enzyme pepsin. Pepsinogen is released by stomach
cells and is converted to pepsin in the presence of hydrochloric acid. Pepsin
breaks proteins down to peptides.
The parietal cells of the stomach also secrete a glycoprotein called intrinsic
factor which enables the absorption of vitamin B-12. Other small molecules, such
as alcohol, are absorbed from the stomach by passing through the membrane of
the stomach and entering the circulatory system directly.
The 'food' that leaves the stomach is called chyme.
*Although iron absorption takes place in the small intestine, it is dissoved
out of foods most effectively in the presence of hydrochloric acid in the stomach.
Small intestine: The chemical digestion of food
is completed in the small intestine and vitually all absorption of nutrients
takes place here. The small intestine has an alkaline pH.
When chyme (acidic from stomach) passed into the small intestine it is mixed
first with pancreatic juice and bile, then with intestinal juice. It is the juice
that completes the digestion of carbohydrates to monocaccharides, proteins to
amino acids and fats to fatty acids and glycerol.
Large intestine or Colon: It takes 12 – 14
hours for contents to make the circuit of the large intestine. The colon
is primarily a storage and dehydration organ. Very little is absorbed from
the large intestine except water. The colon, in contrast to the germ-free
stomach, is lavishly populated with bacteria, normal intestinal flora.
Probiotics and live cultures, such as those found in yoghurt, promote good
intestinal bacteria but many are destroyed in the stomach acid before they
make it to the intestines.
Liver: The main storage organ for fat-soluble
vitamins. The liver can modify almost any chemical structure and is a powerful
detoxifying organ, breaking down a variety of toxic molecules and rendering
them harmless. The liver is a blood reservoir, a storage organ for fat
soluble vitamin A and D, a storage organ for digested carbohydrate (glycogen).
It manufactures enzymes, cholesterol, proteins, Vitamin A (from carotene)
and blood coagulating factors. One of the prime functions of the liver
is to produce bile, which contains salts that promote efficient digestion
of fats.
Gallbladder: Holds bile. Bile helps to digest
and absorb fats and helps create an alkaline environment in the small intestine
when added to chyme ("food" that leaves the stomach).
Pancreas: The pancreas provides the body’s
most important enzymes. Its cell clusters secrete insulin, which accelerates
the burning of sugar in the body. Remember insulin is secreted into the
blood NOT the digestive tract. The pancreas manufactures and secretes pancreatic
juice, which contains digestive enzymes such as lipases, which splits fats,
Proteases, which split proteins and Amylases, which split starches.
NUTRIENTS
The 6 important nutrients are: Carbohydrates, Protein, Fats, Vitamins, Minerals
and Water.
Macronutrients are carbohydrates, proteins, fats and individual fatty acids.
Micronutrients include vitamins, minerals and water.
Macronutrients primarily provide the body with energy, while Micronutrients do
not provide energy to the body.
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MACRONUTRIENTS
Carbohydrates:
Carbohydrates are classified as monosaccharides (1 sugar unit), disaccharides
(2 sugar unit), or polysaccharides (3 or more sugar units) and are the main "fuel" for
the body.
Polysaccharides are often referred to as complex carbohydrates because they are
long chains of sugar units, whereas monosaccharides and disaccharides are simple
carbohydrates.
‘Fast releasing’ or simple carbohydrates (sugar, honey, malt, sweets
and refined foods) metabolized faster and thus raise blood sugar levels quickly
resulting in rapid increases in blood insulin levels. You get a burst of energy
followed by a slump.
‘Slow releasing’ or complex carbohydrates (whole grains, fresh fruit
and vegetables) take longer to metabolize since their sugar units are processed
one-by-one off the ends of the chains. This provides sustained energy.
NOTE: Keep bananas, dates and raisins to
a minimum if you suffer from glucose related health problems.
RDA: Male and female - 130g
Pregnancy: 175g
Lactation: 210g
Calories per gram: 4 (1 Calorie = 4.184 kilojoules)
Protein:
Protein is composed of amino acids and are essential for growth and body tissue
repair; they are used to make hormones, enzymes, anti-bodies and neurotransmitters.
The body requires amino acids to produce new body protein (protein retention)
and to replace damaged proteins (maintenance) that are lost in the urine.
There are 2 types of amino acids: Essential amino acids which cannot be produced/synthesised
in the body and therefore must be supplied in the diet. And non essential amino
acids which we can produce/synthesis in the body. The quality and quantity of
the protein is important to the balance of amino acids in the body. Best quality
protein = eggs, soya, meat, fish, beans and lentils.
Consuming a diet that contains adequate amounts of essential (but also non-essential)
amino acids is particularly important for growth.
Dietary
sources of protein include meats, eggs, grains, legumes, and dairy products
such as milk and cheese.
Runner beans, peas, corn, and broccoli all contain good levels of protein and
help to neutralise the excess acidity in the body.
Proteins can be converted into carbohydrates through a process called gluconeogenesis.
See also High Protein Diets and Ketosis
and
Insulin
RDA: Females (18 - 70yrs) - 46g
Males (18 - 70yrs) - 56g
Pregnancy & Lactation - 71g
Calories per gram: 4
Fats:
Fat may be classified as saturated or unsaturated. Generally, saturated fat is
solid at room temperature while unsaturated fat is a liquid.
Unsaturated
fats can be further classified as monounsaturated (olive oil) and polyunsaturated
(nuts, seed oils & fish).
Certain polyunsaturated fats in the body, called essential fatty acids, are primarily
used to produce hormone-like substances that regulate a wide range of functions,
including blood pressure, blood clotting, blood lipid levels, the immune response,
and the inflammation response to injury infection. These are called linolenic
acid or Omega 3 (Pumpkin and Flax seeds) and linoleic acid or Omega 6 (Sesame
and sunflower seeds, evening primrose oil).
Essential fatty acids are polyunsaturated fatty acids and are destroyed by heating
or exposure to oxygen so a fresh, daily source is important.
Processed food often contains hardened or ‘hydrogenated’ polyunsaturated
fats. These are worse for you than saturated fat and are best avoided. See also Know
your Fats
RDA: No recommended daily allowance has been established for fats.
However, the RDA for essential fatty acids are as follows:
Adults: Omega 3 - 700mg
Omega 6 - 150mg
Calories per gram: 9
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MICRONUTRIENTS
Vitamins: Although needed in much smaller amounts
than fat, protein or carbohydrates, vitamins are no less important.
They ‘turn on’ enzymes, which in turn make all body processes happen.
Vitamins are needed to balance hormones, produce energy, boost the immune system,
make healthy skin and protect the arteries; they are vital for the brain, nervous
system and just about every body process. Read also Vitamins and RDA
vs ODI
Minerals: Like vitamins, minerals are essential
for just about every body process.
Calcium, magnesium and phosphorus help make bones and teethe. Nerve signals,
vital for the brain and muscles, depend on calcium, magnesium, sodium and potassium.
Potassium is also responsible for water balance in the body.
Magnesium is essential for healthy muscles esp. the heart muscle. Oxygen is carried
in the blood by an iron compound.
Chromium helps control blood sugar levels. Zinc is essential for all body repair,
renewal and development. Selenium and zinc help boost the immune system. Brain
function depends on adequate magnesium, manganese, zinc and other essential minerals.
Read also Minerals and RDA vs
ODI
Water:
The human body is 55% to 78% water depending on body size. We lose about 1.5
litres a day through breathing, perspiring, and other bodily functions.
You
should replace water lost through these everyday body funtions - but that
doesn’t necessarily total 8 glasses of water a day. If you exercise
or perspire a lot or eat an unhealthy diet, then you're likely to need
more water.
It’s hard to measure the exact amount of water you have consumed daily
in food and drink, or how much your body needs but remember that the body is
75% water and most advocates agree that 8–10 glasses of water (approximately
2 liters) daily is the minimum to maintain proper hydration.
A good way to tell
if you're dehydrated is:
If you are constipated, you need water in the colon. Water + fibre will sort
you out.
If your urine is pale yellow, you’re doing a good job. If it’s a
darker yellow or orange, drink more H2O.
On average we need 1 glass of water for every 10 kgs we carry in body weight.
For example 60 kgs = 6 glasses of H2O per day.
If you end up with a dry mouth, the last place in the body to dehydrate, you
need those 8 glasses!!!
NOTE: 4 pieces of fruit and 4 servings of vegetables (about 1.1kg) can provide
around 1 litre of water, leaving a daily 1 litre to be taken as water.
SUMMARY
The energy value per gram of various food components includes:
Fat – 37kJ (9 Cal) – not all fatty acids may provide the same amount
of energy
Alcohol – 29kJ (7 Cal)
Carbohydrates – 16kJ (4 Cal) – not all carbohydrates may provide
the same amount of energy
Protein – 17kJ (4 Cal)
Dietary fibre – 13kJ (3 Cal) – if fermented by bacteria in the large
intestine
Water – 0kJ (0 Cal).
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High protein diets are good for you. Or are they?
Know your fats
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RDA vs ODI - Survive or Thrive!!!
Vitamins
What is the H factor - homeocysteine
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