This fact sheet about food and diet is designed to give you the basics about this subject. Topics which will be discussed include the following:
- eating a healthy and balanced diet
- vitamins
- food additives and their effects
- organic food
- GM (genetically modified food)
Because these topics are vast in themselves, hundreds of books have been written about each of these areas of food and diet. Therefore, only the salient points can be covered in this fact sheet. It cannot therefore be viewed as an exhaustive reference text, but more as an overview.
Eating a healthy and balanced diet
In most developed countries, the problems encountered with the diets of most people are not malnutrition but over nutrition. This is caused by over indulging and eating the wrong types of food. This in turn is leading to an epidemic of obesity and obesity related conditions, such as heart disease, diseases of the circulation, strokes, cancers, reduced quality of life and reduced life expectancy.
Therefore, eating the right amount of the right sorts of food is vital if this balance is to be achieved. A balanced diet can be divided into 5 basic components, each of which is important for different reasons and this is summarized below:
-
Carbohydrates
This group should make up around one-third of your daily intake. It includes foods such as potatoes, bread and pasta. Carbohydrates can be further divided into:
- refined: this is food with natural fibre removed such as white bread and sugary breakfast cereals
- unrefined: this is food with a higher natural fibre content and is generally better for you then refined sources. Examples of this include; wholemeal or brown bread, pasta and rice
Foods such as potatoes are a good source of starch and therefore also recommended. However, we generally tend to eat too much of this along with refined carbohydrates at the cost of healthier unrefined foods.
2. Fruit and Vegetables
Fruit and vegetables are an essential and usually under represented part of our daily diets. They are rich in vitamins, minerals and fibre and help to keep such organs as the heart, skin, and hair healthy. They are also thought to help reduce the risk of colorectal cancer. The aim for everyone should be to eat at least 5 portions (preferable more than 5 portions if possible) of fruit and vegetable each day. This can be in any form such as fresh, frozen, canned or dried food. One portion can equate to eating a medium or large piece of fruit (apple, orange, banana), a bowl of salad, 2-3 heaped tablespoons of vegetables, or drinking a glass of fruit juice.
3. Protein
Proteins should make up around one-fifth of our total daily intake. These are important to build and repair our bodies. Proteins can be sourced in 2 ways;
- vegetarian foods: beans, pulses, nuts and soya
- non-vegetarian: meats, fish, poultry and eggs
To keep meats healthier, it is generally recommended to buy the leanest cuts or trim off excess fat before cooking. Also, remove the skin from chicken as this contains most of the fat. Try to eat at least 3 portions of oily fish per week as this is thought to be particularly good for you in other ways as detailed below.
4. Dairy Produce
Milk, cheese and yoghurt are the main constituents of this group for their calcium content. Calcium is vital for strong and healthy bones and teeth. It is important to have around 700 milligrams of calcium daily which equates to approximately 1 pint of milk or 2 small yoghurts. Alternatively, calcium can be obtained from soya milk or leafy, green vegetables if you don’t drink cow’s milk. Dairy products also contain other vitamins, minerals and protein.
It is also important to know that butter and cream are excluded from this group due to their huge fat content.
5. Fat and sugar
This component should make up the smallest part of your daily intake but unfortunately often forms one of the biggest. Foods in this group include butter, crisps, cakes and chocolates. Fats can be divided into;
- saturated: this type of fat is thought to be harmful and responsible for a high proportion of heart disease. Foods include butter, margarine, animal fat and fried foods.
- unsaturated: these fats are thought to be good for you in small amounts as they are important for the normal functioning of the immune system. Foods include oily fish and vegetable oils (e.g. sunflower or olive oils).
Foods with high sugar content usually contain a large number of calories and therefore promote obesity. They are also harmful for teeth and should therefore be reduced from the daily diet.
General dietary advice consists of several major points, some of which are highlighted above. Others include:
- eat more fibre from foods such as cereals, beans, fruit & vegetables especially carrots, cabbage and broccoli,
- eat more oily fish such as mackerel, tuna, salmon and sardines,
- choose leaner cuts of meat,
- eat more poultry (without the skin) instead of red meat,
- reduce the intake of processed meats such as sausages and bacon because of its fat and additive content,
- eat less sugary and fatty foods such as sweets, cakes, biscuits and chocolate,
- reduce salt intake to a maximum of 6 grams daily,
- when cooking vegetables, steam cook rather than boil to retain more of the vitamins,
- avoid using lard and other solid fats for cooking. Use healthier olive oil or sunflower oil instead,
- bake, grill, poach, steam or casserole as methods for cooking rather than frying,
- be careful with your alcohol intake (see separate Fact Sheet on Alcohol).
Vitamins
These compounds which are actually required by us in small quantities, are nonetheless vital for the normal health and functioning of all body organs and systems. A deficiency in any one of these can cause serious problems.
The table below summarizes the main details as regards most of the common vitamins required in daily diet.
Vitamin |
Food source |
Required for |
Deficiency causes |
Vitamin A |
liver, fish oil, green leafy vegetables, egg yolks, carrots, dairy products, yellow fruit |
Good eye sight, growth, appetite and taste |
|
Vitamin B1 (Thiamin) |
liver, yeast, rice, wholemeal flour, peanuts, pork, milk |
nervous system, digestion, muscles, heart |
Beriberi – where nerves become inflamed and fluid accumulates in tissues (oedema) |
Vitamin B2 (Riboflavin) |
milk, liver, yeast cheese, green leafy vegetables |
growth, hair, skin, nails, eyesight |
skin deterioration esp. around nose and mouth |
(Vitamin B3) Niacin or nicotinic acid |
liver, whole grains, eggs, avocado, peanuts, fish, meat |
converting food into energy, production of red blood cells |
Pellagra – a condition causing dermatitis, diarrhea and certain mental illnesses |
(Vitamin B5) Pantothenic Acid |
fish, liver, chicken, muchrooms, cauliflower, potatoes, whole grains, yeast, dried grains and peas, some fruits, milk, eggs |
converting food into energy, relaxation, combating fatigue, allergies, asthma, psoriasis |
|
Vitamin B6 (Pyridoxine) |
fish, banana, chicken, pork, whole grains, dried beans |
skin conditions, neurological problems, protein and carbohydrate absorption |
|
(Vitamin B8) Biotin |
|||
(Vitamin B9) Folate, folacin or folic acid |
carrots, yeast, liver, egg yolk, melon, apricots, pumpkin, avocado, beans, rye, whole wheat, green leafy vegetables |
production of red cells, prevention of neural tube birth defects e.g. Spina Bifida |
Foetal neural tube defects |
Vitamin B12 (Colbalamin) |
fish, liver, beef, pork, milk, cheese, eggs and fortified foods, e.g. margarines and cereals |
production of red blood cells, formation of nerve tissue |
Pernicious anaemia |
Vitamin C (Ascorbic Acid) |
citrus fruits e.g. kiwi, berries, tomatoes, cauliflower, potato, green leafy vegetable, pepper |
immune system, reducing cholesterol, digestive benefits |
Scurvy, poor wound healing and bleeding gums |
Vitamin D (Calciferol) |
cod liver oil, sardines, herring, salmon, tuna, milk, sunlight |
development of bones and teeth |
Ricketts |
Vitamin E (Tochopherol) |
nuts, soya beans, vegetable oil, broccoli, sprouts, spinach, wholemeal products, eggs |
anti-oxidant properties |
|
Vitamin K (Phylloquinone) |
liver, egg yolk, cheese, broccoli, leafy, green vegetable |
blood clotting and bones |
Food Additives
There has been an ongoing debate between consumer groups and the food industry about the extent to which the industry uses food additives and why. An additive is an extra chemical, not usually found in that food and which as been deliberately added for in the production process. There are several hundred food additives and several thousand substances used as flavourings.
All additives excluding flavourings, have in the European Union been given an “E number” and the use of these E numbers has been monitored and regulated strictly. However, many would argue that there are still too many E numbers in our food and there is scope for considerable reduction.
Additives are mainly used to enhance the taste, colour and attractiveness of food or to enable a cheaper manufacturing process and also in some cases as preservatives for food. Health professionals would always argue that most of us eat too little fresh produce and too much processed food and that we should aim for the opposite, thereby reducing our reliance and consumption of additives. In the vast majority of cases, additives are simply there for cosmetic reasons. Here are some examples of the types of additives, there corresponding E numbers and there uses in our food.
Colours (E100-180): these additives make food brighter, healthier looking and may be used to disguise the real ingredients of food. Artificial colours are less frequently used but more natural colourings are still used in surprising ways. For example, E162, from beetroot can be found in strawberry yoghurt.
Preservatives and anti-oxidants (E200-321): these additives help food stay edible and safe for longer. They reduce the build up of bacteria and slow down fats and oils from turning rancid.
Emulsifiers, stabilizers and thickeners (E322-495): these additives help maintain a creamer texture to foods such as ice-creams, margarines and spreads. They also help to bulk up food with the addition of water, air and starches.
Processing Aids (E500-585): these are anti-caking agents that help food flow freely, gelling agents, firming agents and anti-sticking agents.
Flavour enhancers (E620-640): these enhance or modify the taste of food and E621 (sodium glutamate) is well known.
Glazing Agents (E900-914): these additives give food a shiny or polished appearance or act as a protective coating.
Flour treatments, improvers and bleaching agents (E920-928): used in processed bread making.
Packing gases (E941-948): these usually inert gases such as nitrogen help to keep food fresher looking for longer.
Sweeteners (E950-967): these additives enhance the sweetness of food by using artificial sweeteners such as saccharin and aspartame.
Flavours (without E numbers): although some of these additives are natural, many are man made chemicals in laboratories and used to hid the real taste of food or disguise the real ingredients (or lack of them) in food. Unfortunately, these chemicals are not monitored, tested or controlled in the same way as all the above additives.
Many processed foods contain far more fat, sugar or salt than would appear just on the look or taste of that food. They disguise poor quality, cheap food. Our intake of these unhealthy elements is therefore difficult to monitor and control, especially if we are making a conscious effort to reduce our intake of these elements. In addition, certain additives may cause mild irritation or more serious allergic reactions. Examples of common culprits are tabled below.
Colourings |
Preservatives and anti-oxidants |
E102 tartrazine |
E210-219 benzoates |
E104 quinoline yellow |
E220-228 sulphites |
E110 sunset yellow |
E310-312 gallates |
E120 cochineal |
E320-321 BHA, BHT |
E122 carmoisine |
|
E124 ponceau |
|
E129 allura red |
|
E160b annatto |
Although food and drinks aimed at babies are regulated more strictly, other foods which are frequently eaten by young children but which are not sold exclusively for young children are not subject to these stricter controls. Examples of this group includes; fizzy drinks, crisps, sausages, fish fingers, sweets, ice-cream and lolly-pops.
Trying to avoid consuming additives is a difficult problem for at least 4 reasons:
1. The foods that contain additives are extensive and numerous. Although this usually involves the obvious processed foods, even simple, apparently healthy options such as fresh fruits may have chemicals such as preservatives on their skin.
2. Poor labeling. Food labels can be difficult to read and difficult to understand. They may be written in small print and either list additives as “E” numbers or by chemical names. Clearly, most of us will not know the role and possible effects of each of these additives.
3. Some additives do not need to be declared and so are not. Examples of these include;
- solvents used to dilute other additives such as colours
- certain enzymes used in processing
- processing aids such as anti-sticking agents
- gases used in the packing process
4. Some foods are exempt from the whole scheme of declaring additives. Such foods include;
- take-away foods
- unwrapped items such as bread or cakes
- fruits such as apples treated with preservatives
- wine and other alcoholic drinks
- some sweets and chocolate
- eggs – may contained dyes fed to chicken
- farmed fish – may have been fed dyes to enhance their colour.
Organic Foods
In the UK, the term “organic” has a legal definition. Therefore, to call a particular food organic, it must be grown, produced or reared in a specific way, adhering to the relevant organic farming principles and philosophy. Organic foods are therefore certified as such by approved authorities such as “The Soil Association”. This body will, after verification of the processes used, award its symbol to those products it deems as organic and which therefore conform to its standards.
Organic food is thus produced using ecologically friendly scientific methods. This includes such things as;
- using traditional and sustainable methods of farming,
- farming without using chemicals such as insecticides, pesticides, weed killers and artificial fertilizers,
- rearing animals free from drugs such as antibiotics,
- rearing animals in a less intensive method and therefore more akin to their natural environment.
Should you choose to buy organic? The following table details the advantages and disadvantages of buying organic food. The decision to buy organic is therefore a very personal one and really depends on your own current thinking about the issues tabled below:
Advantages |
Disadvantages |
No artificial chemicals, preservatives, antibiotics, pesticides and other additives |
Generally more expensive as lower yield and not intensively farmed |
Environmentally friendly |
May not look as appealing as non-organic food as it may be less colourful and unusual shapes and sizes Less longevity |
Emphasizes animal welfare and issues |
|
Free from genetic modification |
|
Thought to taste better |
|
Possible better vitamin and mineral content |
GM Foods (Genetically Modified)
Recent scientific research as led to many trials of production of food which as been genetically altered from its natural state. GM food therefore incorporates genes from other species which are thought to confer an advantage to that food. Such advantages may include increased resistance to disease or pests or to increased longevity. The process of genetic engineering therefore reduces the need for other measures such as a reliance on additives such antibiotics, pesticides or preservatives.
However, certainly in the UK, there has been hot debate about the merits and pitfalls of genetic manipulation. Some view this process as an obvious and important advancement in farming technique whilst others see this as unnatural and dangerous.
Organic food is GM free and supporters of organic farming often campaign against GM trials and farming. Some of the potential risks of GM food are listed below:
1. Risks to health
- A poor understanding of how newly inserted genes interact with natural genes may cause unknown side effects such as from toxic or undesired chemicals produced inside plants,
- Unexpected food allergies may result. For example, inserting a nut based gene in a soya plant may cause a nut allergy like response in susceptible individuals,
- Possible antibiotic resistance in bacteria,
- The long term affects of consuming GM foods is largely unknown and remains untested as this is still a new technology.
2. Risks to the environment
- GM material may inadvertently be transferred to other crops or weeds with as yet unknown effects and possibly with permanent consequences,
- Other unpredictable effects on the environment such as development of more difficult to eliminate pests and diseases,
- A reduction of beneficial insects as well as the troublesome pests.
3. Risk to consumer choice
- Consumers may not realise that they are eating GM food as labeling is varied and unclear,
- Special groups may not realise what they are eating, e.g. vegans eating vegetarian foods containing meat proteins or religious groups eating foods forbidden by their religion.
Clearly, what we eat and how we eat it is a very emotive subject for all concerned, including farmers, the food industry, doctors, scientists and particularly for consumers. There is no clear consensus about what we should eat in terms of food additives, organic foods and genetically modified foods. However, what is clear is the role of a healthy and balanced diet.
Further information about obesity and dieting can be found in the separate fact sheet entitled “Obesity”.
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