Introduction
Many people worry that when they stop eating meat and fish, they might
be in danger of some nutritional deficiency. This is not the case as all
the nutrients you need can easily be obtained from a vegetarian diet. In
fact research shows that in many ways a vegetarian diet is healthier than
that of a typical meat-eater.
Nutrients are usually divided
into five classes: carbohydrates, proteins, fats (including oil), vitamins
and minerals. We also need fibre and water. All are equally important
to our well-being, although they are needed in varying quantities,
from about 250g of carbohydrate a day to less than two micrograms of
vitamin B12. Carbohydrate, fat and protein are usually called macro-nutrients
and the vitamins and minerals are usually called micro-nutrients.
Most foods contain a mixture
of nutrients (there are a few exceptions, like pure salt or sugar)
but it is convenient to classify them by the main nutrient they provide.
Still, it is worth remembering that everything you eat gives you a
whole range of essential nutrients.
Meat supplies protein, fat,
some B vitamins and minerals (mostly iron, zinc, potassium and phosphorous).
Fish, in addition to the above, supplies vitamins A, D, and E, and
the mineral iodine. All these nutrients can be easily obtained by vegetarians
from other sources, as this Information Sheet shows.
Protein
Women need about 45g of protein a day (more if pregnant, lactating or very
active), men need about 55g (more if very active). Evidence suggests that
excess protein contributes to degenerative diseases. Vegetarians obtain
protein from:
- Nuts: hazels, brazils, almonds,
cashews, walnuts, pine kernels etc.
- Seeds: sesame, pumpkin, sunflower,
linseeds.
- Pulses: peas, beans, lentils,
peanuts.
- Grains/cereals: wheat (in
bread, flour, pasta etc), barley, rye, oats, millet, maize (sweetcorn),
rice.
- Soya products: tofu, tempeh,
textured vegetable protein, veggieburgers, soya milk.
- Dairy products: milk, cheese,
yoghurt (butter and cream are very poor sources of protein).
- Free range eggs.
You have may have heard that it is necessary to balance the complementary
amino acids in a vegetarian diet. This is not as alarming as it sounds.
Amino acids are the units from which proteins are made. There are 20 different
ones in all. We can make many of them in our bodies by converting other
amino acids, but eight cannot be made, they have to be provided in the
diet and so they are called essential amino acids.
Single plant foods do not contain
all the essential amino acids we need in the right proportions, but
when we mix plant foods together, any deficiency in one is cancelled
out by any excess in the other. We mix protein foods all the time,
whether we are meat-eaters or vegetarians. It is a normal part of the
human way of eating. A few examples are beans on toast, muesli, or
rice and peas. Adding dairy products or eggs also adds the missing
amino acids, eg macaroni cheese, quiche, porridge.
It is now known that the body
has a pool of amino acids so that if one meal is deficient, it can
be made up from the body's own stores. Because of this, we don't have
to worry about complementing amino acids all the time, as long as our
diet is generally varied and well-balanced. Even those foods not considered
high in protein are adding some amino acids to this pool.
Carbohydrate
Carbohydrate is our main and most important source of energy, and most
of it is provided by plant foods. There are three main types: simple sugars,
complex carbohydrates or starches and dietary fibre.
The sugars or simple carbohydrates
can be found in fruit, milk and ordinary table sugar. Refined sources
of sugar are best avoided as they provide energy without any associated
fibre, vitamins or minerals and they are also the main cause of dental
decay.
Complex carbohydrates are found
in cereals/grains (bread, rice, pasta, oats, barley, millet, buckwheat,
rye) and some root vegetables, such as potatoes and parsnips. A healthy
diet should contain plenty of these starchy foods as a high intake
of complex carbohydrate is now known to benefit health. The unrefined
carbohydrates, like wholemeal bread and brown rice are best of all
because they contain essential dietary fibre and B vitamins.
The World Health Organisation
recommends that 50-70% of energy should come from complex carbohydrates.
The exact amount of carbohydrate that you need depends upon your appetite
and also your level of activity. Contrary to previous belief a slimming
diet should not be low in carbohydrates. In fact starchy foods are
very filling relative to the number of calories that they contain.
Dietary Fibre
Dietary fibre or non-starch polysaccharide (NSP), as it is now termed,
refers to the indigestible part of a carbohydrate food. Fibre can be found
in unrefined or wholegrain cereals, fruit (fresh and dried) and vegetables.
A good intake of dietary fibre can prevent many digestive problems and
protect against diseases like colon cancer and diverticular disease.
Fats & Oils
Too much fat is bad for us, but a little is necessary to keep our tissues
in good repair, for the manufacture of hormones and to act as a carrier
for some vitamins. Like proteins, fats are made of smaller units, called
fatty acids. Two of these fatty acids, linoleic and linolenic acids, are
termed essential as they must be provided in the diet. This is no problem
as they are widely found in plant foods.
Fats can be either saturated
or unsaturated (mono-unsaturated or poly-unsaturated). A high intake
of saturated fat can lead to a raised blood cholesterol level and this
has been linked to heart disease. Vegetable fats tend to be more unsaturated
and this is one of the benefits of a vegetarian diet. Mono-unsaturated
fats, such as olive oil or peanut oil, are best used for frying as
the poly-unsaturated fats, like sunflower or safflower oil are unstable
at high temperatures. Animal fats (including butter and cheese) tend
to be more saturated than vegetable fats, with the exception of palm
oil and coconut oil.
Vitamins
Vitamin is the name for several unrelated nutrients that the body cannot
synthesise either at all, or in sufficient quantities. The one thing they
have in common is that only small quantities are needed in the diet. The
main vegetarian sources are listed below:
 Vitamin
A (or beta carotene):
Red, orange or yellow vegetables like carrots and tomatoes, leafy green
vegetables and fruits like apricots and peaches. It is added to most
margarines.
B
Vitamins: This group
of vitamins includes B1 (thiamin), B2 (riboflavin), B3 (niacin), B6
(pyridoxine), B12 (cyanocobalmin), folate, pantothenic acid and biotin.
All the B vitamins
except B12 occur in yeasts and whole cereals (especially wheat germ),
nuts & seeds,
pulses and green vegetables.
Vitamin
B12 is the only one that may cause some difficulty as it is not present
in plant foods.
Only very tiny amounts of B12 are needed and vegetarians usually get
this from dairy produce and free range eggs. It is sensible for vegans
and vegetarians who consume few animal foods to incorporate some B12
fortified foods in their diet. Vitamin B12 is added to yeast extracts,
soya milks, veggieburgers and some breakfast cereals.
Vitamin
C: Fresh fruit,
salad vegetables, all leafy green vegetables and potatoes.
Vitamin
D: This is vitamin
is not found in plant foods but humans can make their own when skin
is exposed to sunlight. It is also added to most margarines and is
present in milk, cheese and butter. These sources are usually adequate
for healthy adults. The very young, the very old and anyone confined
indoors would be wise to take a vitamin D supplement especially if
they consume very few dairy products.
Vitamin
E: Vegetable
oil, wholegrain cereals, eggs.
Vitamin
K: Fresh vegetables,
cereals and bacterial synthesis in the intestine.
Minerals
Minerals perform a variety of jobs in the body. Details of the some of
the most important minerals are listed below:
Calcium: Important for healthy bones and teeth. Found in dairy produce, leafy
green vegetables,
bread, tap water in hard water areas, nuts and seeds (especially sesame
seeds), dried fruits, cheese. Vitamin D helps calcium to be absorbed.
Iron: Needed for red blood cells. Found in leafy green vegetables, wholemeal
bread, molasses,
eggs, dried fruits (especially apricots and figs), lentils and pulses.
Vegetable sources of iron are not as easily absorbed as animal sources,
but a good intake of vitamin C will enhance absorption.
Zinc: Plays a major role in many enzyme reactions and the immune system.
Found in green vegetables,
cheese, sesame and pumpkin seeds, lentils and wholegrain cereals.
Iodine: Present in vegetables, but the quantity depends on how rich the soil
is in iodine. Dairy products
also have plenty of iodine. Sea vegetables are a good source of iodine
for vegans.
|
