Food Basics
FOOD GLORIOUS FOOD
There are a few things which constitute good food, and many things which are
eaten which are not foods at all. One definition of food is "any nonpoisonous,
organic substance that we can transform into living tissue" (1). No single
food is able to sustain health. We require a mixed and. balanced diet.
An efficient diet aims at conserving energy that is, taking the essential
proteins, fats, carbohydrates, vitamins, minerals, enzymes and water direct
from their sources without wastage (2). These key elements are contained in
most of the foods that you can grow and preserve yourself. Carbohydrates,
vitamins, minerals and dietary fibre can all be provided by raw fruits and
vegetables, preferably fresh, and our need for proteins and fats can be satisfied
from plant or animal sources.
Food only becomes part of the body after being dismantled by the action of
teeth, saliva, gastric juices, enzymes, muscular movements of the intestines
and absorption by the bloodstream. The processes of chemical breakdown and
build-up in the body are called metabolism.
PROTEIN
Our bodies need protein for growth, repair and enzyme formation; any excess
is wasted by oxidation to provide energy or body fat. But overconsumption
of protein accelerates the metabolism, strains the liver and kidneys and can
cause calcium deficiency.
The total amount of protein in a food gives no indication of the amount available
to the body and there is a wide disagreement on protein requirements. But
the important thing is not so much to count grammes of protein as to make
sure we do not waste it. We can cut down on our protein requirements by eating
plant protein instead of meat.
If we examine the efficiency of various food production systems we find that
leafy crops such as comfrey, alfalfa, kale and spinach can produce 26 times
more protein per acre than beef cattle. Legumes average 10, cereals 5, and
milk 2 times more protein per acre than beef. (3).
Plant proteins provide 70 per cent of the world's supply, yet people still
believe that animal protein is essential. But according to the HMSO Manual
o f Nutrition (4); "If protein in the diet is supplied from . . . a very
carefully chosen selection of vegetable foods, the amount required may be
as little as if it came from animal sources alone, because the variety of
amino acids available may enable the body to turn it economically into human
protein." Which means that in a garden or allotment of suitable size,
we can grow all the foods needed for a healthy diet.
The simplest sources of protein, in order of directhess, are leaf and root
vegetables, fruits and nuts, legumes and cereals, goats milk, yoghurt, cheese
and free-range eggs. In leaves, roots and fruits, however, the large proportion
of inedible fibre, and the water-to-protein ratio, makes them unsuitable as
a protein source-though the protein can be extracted by processing (5).
PROTEIN COMBINATIONS
In the body, proteins are dismantled into the 22 amino acids. Of these, 14
can be synthesized by the body, while the other 8, called essential amino
acids (EAAs) may be supplied in the diet. Growing children also require arginine
and histidine. Body protein can only be formed efficiently if all the 8 EAAs
are combined in one meal in correct proportions. A meal slightly deficient
in one or more EAAs will give less protein than a correctly balanced meal.
What is this correct amino acid pattern? Mother's milk combines the EAAs,
fats and less important nutrients in ideal proportions for the nutrition of
babies. Only two per cent of cow's milk protein is wasted through incomplete
digestion and absorption (6). However, our requirements change during weaning
and when growth is complete.
Some nutritionists have taken the egg as the ideal EAA pattern (7). The egg
is given a net protein utilization (NPU) of 100 per cent (NPU is the proportion
of nitrogen intake that is retained). NPU values for foods can be found in
(8) and (9). The importance of NPU is stressed in (8) and its companion volume
(10), which contains many recipes for foods combined to increase protein utilisation.
Fig 1 gives one example.
VITAMINS AND MINERALS
Vitamins and minerals are essential for good health and are closely associated
with the regulation of the metabolism. They are found in most fresh, unprocessed
foods, especially raw fruits and vegetables, and are needed regularly in small
amounts. (Likely deficiencies, however, are B12 and D) The watersoluble vitamins
(C and the B group) are easily destroyed or lost, usually down the drain with
the cooking water. B vitamins, abundant in brewers yeast and sprouted wheat,
are concerned with the release of energy from foods. Vitamin C, essential
for growth, the healing of wounds, healthy teeth and bones is obtained if
plenty of fresh raw fruit and vegetables are eaten.
The body has a limited ability to synthesize vitamin K and D. D is essential
for calcium and phosphorus absorption, healthy bones and teeth.
Of the B vitamins, Biotin can be synthesized, and Nicotinic acid can be formed
from the amino-acid trytophan. B12 prevents primary anaemia and is made in
the intestine by E.coli bacteria, but usually too low down for absorption.
Other sources are brewers yeast, wheat germ, soybeans and comfrey. Vitamins
A, E and P are all available from plant sources.
Enzymes, regulators of chemical processes are destroyed and minerals such
as magnesium are leached away during cooking.
FATS AND CARBOHYDRATES
These supply the calories of energy needed to move and warm the body. Though
fats supply more energy, carbohydrates are quite adequate and too much saturated
fat should be avoided. If taken in excess, fats and carbohydrates are converted
into body fat.
The three essential fatty acids (EFAs) must be supplied in the diet since
the body cannot synthesize them. They are needed for the utilizatior of carotene
and the fat-soluble vitamins. Two important EFAs are found (with vitamins
A, D and E) in the germ of cereals, in-nuts and vegetable seed oils. If eaten
with fat, foods are retained longer in the stomach, delaying the feeling of
hunger.
Carbohydrates are sugars, starches and celluloses built up in plants from
carbon dioxide and water by photosynthesis. Sugars are starches broken down
into glucose (a simple sugar) to provide energy.
Cellulose is not digestible but provides essential fibre or bulk to the diet.
Lack of fibre causes intestinal disorders.
HEALTH AND ECONOMY
Eat foods whole for a balanced diet. The core of apples contains 24 times
more iodine than the other parts (11) and the skins of fruits contain minerals
such as magnesium. Harvest, rinse, scrub and prepare food immediately before
eating. Digestion is easier if each meal is started with raw food. Enjoy and
chew food thoroughly; this is essential for good digestion and helps prevent
over-eating. Drinking at meal times dilutes and weakens the digestive juices.
Don't patronise supermarkets, their philosophy is to profit from low-quality,
over-processed, over-packaged food-substitutes. Refined ca rates can cause
illness. Try to get foods fresh rom their source. High water content foods
(organically grown apples, cabbage, etc.) can supply better liquid than taps,
endless cups of tea, coffee, cola or alcohol. Make a habit of sprouting nutritious
grains and protein-rich legumes (2), which are delicious with grated, raw
salads (12). Make your own yoghurt (13) and to make sure you get good food
value; grow your own fruit and vegetables (14).
REFERENCES
(1) Shelton, H.H. (1969) Health for the Millions Natural Hygiene Press, USA
(2) Shore, J. (1974) 'Organic Living Experiment' Undercurrents 6 and 8, London
(3) Wokes, F. (1968) 'Proteins' Plant Foods in Human Nutrition
Pergamon, London
(4) Min. Agric. Fish. Food (1970) Manual of Nutrition HMSO, London
(5) Byers, M., Green, S.H. and Pirie, N.W. (1965) Nutrition 19, 63
(6) Fox and Cameron (1968) A Chemical Approach to Food and Nutrition Univ.
of London Press, London
(7) FAO/WHO (1965) Protein Requirements Report 37, Rome
(8) Lappe, F. (1971) Diet for a Small Planet Friends of the Earth/ Ballantine,
New York
(9) FAO (1970) Amino-Acid Content of Foods and Biological Data on Protein,
Rome
(10) Ewald, E. (1973) Recipes for a Small Planet Ballantine Books, New York
(11) Bircher-Benner (1971) Fruit Dishes and Raw Vegetables C.W. Daniel, Essex
(12) Bircher, R. (1961) Eating Your Way to Health Faber and Faber, London
(13) Hills, H.C. (1970) Housewives Help Vol 2, Henry Doubleday Research Assoc,
Essex
(14) Hills, L.D. (1974) Dig for Survival Henry Doubleday Research Assoc. 20
Convent Lane, Bocking, Braintree, Essex
