High-quality protein

Our bodies are composed mainly of protein, which (after water) is the most abundant substance in the body. It is the major constituent of our muscles, tissues, skin, hormones, enzymes, antibodies and blood. Even after childhood protein plays a vital role in maintaining and rebuilding our bodies as they cope with the wear and tear of daily life.

Proteins are broken down by the process of digestion into units called amino acids, and the body requires 22 amino acids to form human protein. All but nine can be produced in the body. These nine are known as 'essential amino acids' and have to be provided in the diet. Foods that contain all nine are termed 'complete proteins', and they include meat, fish, dairy and soya protein. Fruit, vegetables, grains and pulses are 'incomplete proteins' and have to be carefully combined to provide sufficient amino acids in the diet.

Protein is fundamental to rebalancing blood-sugar levels, because it encourages production of the hormone glucagon, which helps the body to release stored glycogen for energy and encourages the burning of fat. Glucagon also helps to balance excess insulin production.

What is Biological Value?

In order to be efficient, protein foods have to be of a high quality and have what is termed a high Biological Value (BV) — this indicates how much of theprotein is retained by the body. Eggs used to be classed as having the highest BY, but micro-filtered whey, whey-peptide blends and lactalbumin (whey- protein concentrate) are even higher. Micro-filtered whey protein used to be a useless by-product of cheese manufacturing. Now it is processed at very lowtemperatures and turned into a protein source with a very high BV that contains all essential and non-essential amino acids.

The only whey to go

To maintain a healthy immune system, blood, skin and muscles, you need to consume protein with a high By. Whey protein (which is derived from milk, see Q&A opposite) is an excellent supplement that has long been used by bodybuilders and athletes alike. It has many uses in a dietary regime:

¨ It encourages the formation of lean muscle mass

¨ It increases glutathione levels, which has great antioxidant and immune- boosting properties

¨ It helps to build healthy new collagen

¨ It provides an invaluable source of protein for vegetarians who are attempting to balance their diets

¨ It is a quick and easy way of having a high-protein meal or snack

¨ It can be incorporated into recipes as a replacement for carbohydrate ingredients.

There are a multitude of whey products on the market — some better than others. Many come in sweet flavours, which are great when making shakes and smoothies, but you need to source natural, unflavoured products if you want to incorporate whey-protein powder into savoury dishes such as soups. These are widely available through health-food stores and on the Web. Just make sure you don't confuse them with slimmer's meal-replacement powders, which are usually laden with carbohydrates.

The average serving of whey protein is a 25g (1 oz) scoop, but check on the label to see how much of that scoop comprises protein: the lower the protein content, the higher the carbohydrate content. And beware of `blends': these are likely to be bulked up with milk and soya derivatives. To get the best out of your whey products, go for the highest protein concentration possible.

Performance enhancement in perspective

There are countless nutritional products aimed at the sportsperson, which claim to have some performance-enhancing ability. These substances, called `ergogenic aids', theoretically improve performance to a point above that obtainable through a good training programme. Athletes are very susceptible to any claims for even the slightest improvement in performance, as fractions of a second could mean the difference between winning or losing.

Many ergogenic aids are basically expensive forms of proteins, minerals and vitamins. Their effectiveness is often unproven, based on folklore and reliant on the ignorance of the consumer (for example, substances such as Royal Jelly and wheat germ oil). On the other hand, some performance-enhancing principles are based on reputable scientific evidence that have been shown to improve performance in the laboratory (such as carbohydrate supercompensation - see overleaf).

However, it is interesting that even in cases where the supplement or _special diet has no physical basis, an athlete can sometimes gain purely psychological benefit from consuming something he or she believes in.

Proteins and amino acids

Although certain athletes may need an increased amount of protein, taking excessive amounts in the form of powdered or liquid supplements is unnecessary. Despite the claims of manufacturers, large quantities of protein will have no beneficial effects on muscle growth, strength or on performance. Any excess will simply be used as an energy source or stored as fat. In addition, kidney function may be hampered and dehydration caused as a result of taking in too much protein.

The supplements currently in vogue - especially among body builders and weight lifters - are amino acids, the 'building blocks' of proteins. The theory is that certain amino acids stimulate growth hormones. The increase however is slight and has no practical effect. Amino acids are not 'fat burners' or detoxifiers as has been claimed. Although tablets taken for this purpose are extremely expensive, the amount of amino acids in them is very small. In fact, a single egg contains far more than that found in seven or more amino acid tablets!

Vitamins and minerals

As mentioned earlier in this chapter, supplementing vitamins and minerals has no performance-enhancing properties in an athlete whose normal diet is not deficient. The effects of taking megadoses of certain vitamins may even impair performance.

Manufacturers and quasi-nutritionists have given certain substances vitamin status, although they are not scientifically classified as vitamins. For example, pangamic acid (otherwise known as vitamin B15) supposedly prevents various diseases, slows the ageing process and improves physical performance. None of these claims has been substantiated. Laetrile or vitamin B17 is a source of cyanide and has been banned. Other `pseudovitamins' are orotic acid (vitamin B13), bioflavenoids and vitamin B-T (or carnitine), all of which do not function as vitamins.

Carbohydrate loading

`Carbo-loading' is a phrase which has passed into common use. It has been proved scientifically that carbohydrate loading (otherwise known as carbohydrate supercompensation) is one of the practices which is effective in improving performance. It may be explained in the following way: Exercise which lasts for longer than 60-90 minutes is dependent on the amount of glucose available. Glycogen (glucose) stores in the muscle and liver are small, so enlarging them allows an athlete to continue exercising at a higher intensity for longer. A carbohydrate-loading programme increases the amount of muscle glycogen stored before you need to use it.

The best method of doing this is to gradually reduce the amount of training you do during the six days preceding an event and, during the final three days, eat a diet that is high in carbohydrate (500-600 grams per day). The extra glycogen stored in this way allows the athlete to continue exercising for longer.

Carbohydrates, fluids and sodium during exercise

It has been proved that supplying the body with carbohydrate during endurance-type exercise has a glycogen sparing effect which allows an athlete to exercise for longer. Many studies have been done in attempts to find a solution that will allow the maximum amount of water to be absorbed, while at the same time providing an optimal amount of carbohydrate. So far, it seems that a form of carbohydrate known as 'glucose polymers' has the best absorption rate. These are chains of glucose molecules linked together. A solution containing about 10 per cent carbohydrate in the form of glucose polymers supplies the most glucose to the body during exercise, and at the same time provides sufficient water replacement. (It is important to remember that a carbohydrate solution is only of benefit during prolonged exercise.)

Adding sodium to replacement fluids increases the concentration of the fluid. It was initially thought that this would hamper the absorption of the fluid, but the most recent findings suggest that the addition of a very small amount of salt (1-2 grams per litre) is in fact necessary for absorption.

Alcohol

Not surprisingly, it has been proved that alcohol has no beneficial effect on exercise. In reality alcohol is a depressant that slows reaction time, impairs muscle reflexes and disturbs coordination. In addition, it causes dehydration which interferes with fluid balance and has a negative effect on performance.

Caffeine

Some athletes use caffeine as a stimulant and to increase the amount of free fatty acids in the blood. Theoretically, more fat is then available to be used for energy, resulting in glycogen sparing (see above). However, an excessive amount of caffeine is necessary to produce this effect and, apart from the fact that a very high concentration of it in the urine can disqualify a competitive athlete, there are several other disadvantages to using caffeine in this way. The main one is that it has a diuretic effect, which results in increased fluid losses and a greater risk of dehydration. In addition, overconsumption of caffeine can result in headaches and nausea and it is therefore not advisable to use large doses of this stimulant in an attempt to enhance performance.

Other imposters

Royal jelly, wheat germ oil, ginseng, extracts of various herbs and numerous other products have all at one time or another been touted as performance-enhancers. The truth is, however, that the only possible effect most of these substances could have would be a psychological one.

Essential Nutrient Building Blocks of PROTEIN

Next to water, protein is the most plentiful substance in your body. It is primarily involved in the growth, repair and development of all body tissues. It is an essential nutrient that is made up of a long chain of amino acids, commonly known as the building blocks of protein. Protein is found in the outer and inner membranes of every living cell. Even our DNA is made up of nucleoproteins.


Your body needs approximately 50-60 g of protein every day, which you can get from animal sources (such as meat or dairy) and plant sources (such as tofu or nuts). If you do not get enough protein, your body will start to digest other proteins such as the protein in muscle. This is, however, rare in modern diets, as protein is consumed in fairly high amounts of around 120 g per day.

Your body requires 22 different amino acids to make the proteins it needs. Nine of these are considered essential, which means you need to obtain them from your diet, and the rest are non-essential, meaning your body can manufacture them itself from carbohydrates, fats and other amino acids.


The quality of protein

The quality of protein is measured by how well the human body can absorb it. Because animal products (like beef, pork, chicken, fish, cottage cheese and eggs) contain a similar amino acid formation as is present in the human body, they are absorbed more efficiently and therefore called a high-quality protein, or complete protein. However, some can be higher in saturated fat than plant proteins your protein intake by combining different incomplete, plant-based proteins. For example, legumes (beans) complement nuts and seeds, so a meal consisting of chilli beans plus a salad sprinkled with pumpkin seeds, or chilli beans with cheese sprinkled on top would both be excellent ways to combine incomplete proteins. A cup of yoghurt with chopped nuts sprinkled on top is a great example. Another is whole-grain rice and beans.

(The egg is considered a fantastic protein food because it provides the right amounts of all the essential amino acids and therefore is most useful to the human body.)

One of our favourite quick protein meals is a Protein Omelette. Also we have given you our Baked Salmon Loaf. A great snack for a busy day is a Fruit Smoothie - take it with you in a thermos. All these meals are quick to prepare - ideal for times when you are busy but want good healthy food.