                           VegSocUK Information Sheet
                             THE VEGETARIAN SOCIETY


   ___________________________________

                                    PROTEIN

   Being vegetarian does not mean your diet will be lacking in protein. Most
   plant foods contain protein and in fact it would be very difficult to design
   a vegetarian diet that is short on protein. Excess dietary protein may lead
   to health problems. It it now thought that one of the benefits of a
   vegetarian diet is that it contains adequate but not excessive protein.

   Proteins are made up of smaller units called amino acids. There are about 20
   different amino acids, eight of which must be present in the diet. These are
   the essential amino acids. Unlike animal proteins, plant proteins may not
   contain all the essential amino acids in the necessary proportions. However,
   a varied vegetarian diet means a mixture of proteins are consumed, the amino
   acids in one protein compensating for the deficiencies of another.

  STRUCTURE & FUNCTIONS

   Proteins are highly complex molecules comprised of linked amino acids. Amino
   acids are simple compounds containing carbon, hydrogen, oxygen, nitrogen and
   occasionally sulphur. There are about 20 different amino acids commonly found
   in plant and animal proteins. Amino acids link together to form chains called
   peptides. A typical protein may contain 500 or more amino acids. Each protein
   has it's own unique number and sequence of amino acids which determines it's
   particular structure and function.

   Proteins are broken down into their constituent amino acids during digestion
   which are then absorbed and used to make new proteins in the body. Certain
   amino acids can be made by the human body. However, the essential amino acids
   cannot be made and so they must be supplied in the diet. The eight essential
   amino acids required by humans are: leucine, isoleucine, valine, threonine,
   methionine, phenylalanine, tryptophan, and lysine. For children, histidine is
   also considered to be an essential amino acid.

   Proteins are essential for growth and repair. They play a crucial role in
   virtually all biological processes in the body. All enzymes are proteins and
   are vital for the body's metabolism. Muscle contraction, immune protection,
   and the transmission of nerve impulses are all dependent on proteins.
   Proteins in skin and bone provide structural support. Many hormones are
   proteins. Protein can also provide a source of energy. Generally the body
   uses carbohydrate and fat for energy but when there is excess dietary protein
   or inadequate dietary fat and carbohydrate, protein is used. Excess protein
   may also be converted to fat and stored.

  DIETARY SOURCES

   Most foods contain at least some protein. Good sources of protein for
   vegetarians include nuts and seeds, pulses, soya products (tofu, soya milk
   and TVP), cereals (wheat, oats, and rice), free-range eggs and some dairy
   products (milk, cheese and yoghurt).

   Different foods contain different proteins, each with their own unique amino
   acid composition. The proportions of essential amino acids in foods may
   differ from the proportions needed by the body to make proteins. The
   proportion of each of the essential amino acids in foods containing protein
   determines the quality of that protein. Dietary proteins with all the
   essential amino acids in the proportions required by the body are said to be
   a high quality protein. If the protein is low in one or more of the essential
   amino acids the protein is of a lower quality. The amino acid that is in
   shortest supply is called the limiting amino acid.

   Protein quality is usually defined according to the amino acid pattern of egg
   protein, which is regarded as the ideal. As such, it is not surprising that
   animal proteins, such as meat, milk and cheese tend to be of a higher protein
   quality than plant proteins. This is why plant proteins are sometimes
   referred to as low quality proteins. Many plant proteins are low in one of
   the essential amino acids. For instance, grains tend to be short of lysine
   whilst pulses are short of methionine. This does not mean that vegetarians or
   vegans go short on essential amino acids. Combining plant proteins, such as a
   grain with a pulse, leads to a high quality protein which is just as good,
   and in some cases better, than protein from animal foods. Soya is a high
   quality protein on its own which can be regarded as equal to meat protein.

   The limiting amino acid tends to be different in different proteins. This
   means when two different foods are combined, the amino acids in one protein
   can compensate for the one lacking in the other. This is known as protein
   complementing. Vegetarians and vegans eating a well-balanced diet based on
   grains, pulses, seeds, nuts and vegetables will be consuming a mixture of
   proteins that complement one another naturally without requiring any
   planning. Beans on toast, cheese or peanut butter sandwich, muesli with milk
   (soya or cow's), and rice with peas or beans are all common examples of
   protein complementing.

   Previously, it has been thought that protein complementing needed to occur
   within a single meal. However, it is now known that this is not necessary as
   the body keeps a short-term store of the essential amino acids. A
   well-balanced vegetarian or vegan will easily supply all the protein and
   essential amino acids needed by the body.

    Good sources of protein (single servings)

Chick peas (200 g or 7 oz)      16.0 g
Baked beans (225 g or 8 oz)     11.5 g
Tofu (140 g or 5 oz)            10.3 g
Cow's milk (1/2 pint)           9.2 g
Lentils (120 g or 4 1/4 oz)     9.1 g
Soya milk (1/2 pint)            8.2 g
Muesli (60 g or 2 1/4 oz)       7.7 g
Egg, boiled                     7.5 g
Peanuts (30 g or 1 oz)          7.3 g
Bread, (2 slices)               7.0 g
Hard cheese (30 g or 1 oz)      6.8 g


    Fair Sources

Brown rice (200 g or 7 oz)      4.4 g
Porridge [water] (160g or 6oz)  2.4 g
Potatoes (200g or 7 oz)         2.8 g
Broccoli (100g or 3 1/2 oz)     3.1 g

    Poor sources

1 Apple                         0.3 g
1 Carrot                        0.4 g
Cream, double (20 g or 2/3 oz)  0.3 g
Butter or margarine (7g or 1/4oz) None
Vegetable oil                   None
Sugar or syrup                  None

  REQUIRED INTAKES

   The old Recommended Daily Amounts (RDA's) have now been replaced by the term
   Reference Nutrient Intake (RNI). The RNI is the amount of nutrient which is
   enough for at least 97% of the population.  Research has shown that we do not
   need as much protein as previously thought. The recommended amounts of
   protein for adults and children has more than halved in the last 20 years.

    Reference Nutrient Intakes for Protein, g/day.

Age                     RNI

0 to 3 months           12.5 g
4 to 6 months           12.7 g
7 to 9 months           13.7 g
10 to 12 months         14.9 g
1 to 3 yrs              14.5 g
4 to 6 yrs              19.7 g
7 to 10 yrs             28.3 g

Men 11 to 14 yrs        42.1 g
Men 15 to 18 yrs        55.2 g
Men 19 to 49 yrs        55.5 g
Men 50 + yrs            53.3 g

Women 11 to 14 yrs      41.2 g
Women 15 to 18 yrs      45.4 g
Women 19 to 49 yrs      45.0 g
Women 50 + yrs          46.5 g

Pregnant women          51.0 g
Breast feeding women    53 to 56 g

   Increased protein needs during pregnancy and breast feeding are usually met
   simply by the extra calories from more food. Because infants and children are
   growing they require more protein than adults (proportional to their body
   weight).  Children on a balanced diet usually get enough protein as long as
   they are getting enough energy (or calories).

   RNI values for protein are valid only if energy needs are also met. If energy
   needs are not met then dietary protein is used for energy rather than tissue
   growth and repair. This is not generally of concern to vegetarians as plant
   sources of protein tend to also be a good source of carbohydrate, used for
   energy.

   Contrary to popular belief athletes and those who engage in a lot of exercise
   do not necessarily need extra protein as the extra energy required for
   strenous activity is best supplied by carbohydrates. The extra protein needs
   of a body builder can usually be supplied by an increased energy intake from
   more food.

   Whilst vegetarian diets usually meet or exceed protein requirements, they are
   typically lower in total intake of protein than non-vegetarian diets. This
   lower protein intake may well be beneficial as high protein intake has been
   associated with osteoporosis and aggravating poor or failing kidney
   functioning. It is recommended that protein intake should not exceed twice
   the RNI.

  MEAL PLAN

   Sample one day's meal plan to meet the RNI of 45g for an adult women.

Breakfast

Museli (60g or 2oz)             7.7 g
Milk (1/4 pint)                 4.6 g

Lunch

Two slices of toast (80 g or 2 2/3 oz) 7.0 g
Baked beans (225 g or 8 oz)     11.5 g

Evening meal

Brown rice (200g or 7oz)         4.4 g
Tofu (140g or 5oz)              10.3 g
Vegetables
Fruit

TOTAL PROTEIN INTAKE            45.5 g

   An extra two slices of bread and , pint of milk gives 11.6 g protein and
   would easily reach male requirements of 55.5 g/day.
   ___________________________________


//
This article is copyright to the Vegetarian Society (UK), but may be freely
copied for non-commercial use provided it is kept intact, not altered
and these lines are included.

For futher information contact: The Vegetarian Society, Parkdale, Dunham Road,
Altrincham, Cheshire WA14 4QG, England. Tel: (England) 061 928 0793
email: vegsoc@vegsoc.demon.co.uk
//



[The text of this file was obtained from the Vegetarian Society (UK) in
March 1995.]

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