Diet & Nutrition
NHS Direct Online Health Encyclopaedia
Good health is fundamental to leading a full and active life and getting the right nutrition is an important step towards good health.
The word diet is often used to describe an eating plan intended to aid weight loss. However, diet really refers to the foods a person eats in the course of a day or week. The more balanced and nutritious the diet, the healthier the person can expect to be. A balanced diet means eating the right amount of foods from all food groups.
The benefits of a balanced diet are numerous. The right amount of vitamins and nutrients can increase life expectancy, by keeping the heart and body healthy, thereby preventing many long-term illnesses.
Body weight can also be kept to an acceptable level through healthy eating, leading to a fitter and more active lifestyle.
A balanced diet can lower the risk of infectious diseases and this is apparent in the reduction of diseases such as cholera, diphtheria and polio in England.
Healthy eating is about maintaining a balanced diet. This means eating foods from all the different food groups in the right amounts.
There are five main food groups, and each one contains nutrients that are essential for growth, energy and body maintenance. Nutrients are vitamins and minerals that regulate the body’s chemical processes and functions and help to keep you fit and healthy.
The five main food groups are:
Carbohydrates include foods like bread, pasta and potatoes. They should make up about one third of your diet.
Carbohydrates are divided into two groups – refined and unrefined. Refined carbohydrates include white bread and sugary cereals that have had the fibre removed. Unrefined carbohydrates include brown and wholemeal bread, pasta and rice, and you should choose these options whenever possible.
Some people think starchy foods are fattening. However, it’s the fats that are added to them, such as butter and cheese, which can make them unhealthy.
Fruit and vegetables are rich in vitamins and minerals. As well as keeping your skin and hair healthy, they can reduce your risk of getting heart disease and some cancers. You should aim to eat five portions of fruit and vegetables each day. They can be fresh, frozen, canned or dried. One portion counts as one glass of fruit juice, a large piece of fruit such as an apple or banana, or three heaped tablespoons of vegetables.
Protein helps to build and repair the body, and should make up about one fifth of what you eat each day.
Protein includes meat, fish and eggs, as well as non-animal products such as beans and nuts. To keep it healthy, trim fat from meat, remove the skin from chicken, and try to eat two portions of fish each week.
Vegetarians can get the protein they need by including seeds, nuts, soya products and beans in their meals.
Cheese, milk and yoghurt are all examples of dairy foods (cream and butter are in the fats group). Dairy products are rich in calcium, which is important for strong bones and teeth. You should aim to get 700mg of calcium each day, which is roughly the same as a pint of milk or two small yoghurts.
If you don’t drink cows milk or eat dairy products, you can get calcium from soya milk and yoghurts with added calcium, and from leafy green vegetables.
Fats and sugars should make up the smallest part of your diet. This includes foods such as butter, chocolate, crisps and cakes.
Fats are divided into two groups – saturated and unsaturated. Saturated fat is found in cream, margarine and fried foods. This type of fat can contribute to heart disease. Unsaturated fat is found in vegetable oils and oily fish. Eating a small amount helps to keep the immune system healthy.
Sugary foods are bad for your teeth and full of calories that pile on the pounds. Eat them sparingly as a special treat.
Over 200,000 people die prematurely in the UK every year because of coronary heart disease, stroke and other illnesses related to poor diet and unhealthy lifestyle. Those who survive these conditions may be left with pain, long-term disability and a restricted lifestyle.
People in England generally eat too much food, and too much of their diet contains an excess of fat, salt and sugar.
- Take the 5-a-day fruit and veg test
There are many health risks associated with not eating a balanced diet. Specifically these include:
- Ascorbic acid / vitamin C. Prolonged deficiency can result in scurvy, poor wound healing and bleeding gums.
- Thiamin / vitamin B1. Deficiency can lead to Beriberi, a condition common in Southeast Asia, which causes inflammation of the peripheral nerves and large collections of fluid in the body tissue called edemas.
- Riboflavin / vitamin B2. Deficiency leads to deteriation of the skin around the nose and mouth.
- Niacin / nicotinic acid. Deficiency leads to pellagra, a condition characterized by dermatitis, diarrhea and certain mental health problems.
- Colbalamin / vitamin B12. Deficiency may lead to pernicious anaemia.
- Folate / folacin / folic acid. Deficiency in pregnant women increases risk of foetal abnormalities.
- Eating too much salt can raise your blood pressure and triple your risk of heart disease and stroke. Reducing the amount of salt you eat can lower your blood pressure in just four weeks.
Over-eating or eating a daily diet containing too much saturated and unsaturated fat may lead to obesity. Obesity is an excessive amount of fat or body weight and can lead to poor health including heart disease and heart attack. There is some evidence to suggest that obesity and an unhealthy diet may also increase the risk of cancers such colorectal (bowel) cancer. Colorectal cancer is the second commonest cancer in women in Britain and the third commonest cancer for men.
A healthy diet may significantly reduce the risk of colorectal cancer:
- eat more fibre from cereals, beans, fruit and vegetables, particularly carrots, cabbage and broccoli;
- choose lean cuts of meat and stick to oily fish like mackerel, tuna, salmon and sardines and poultry instead of red meat and processed sausages and bacon;
- eat less sugary and fatty foods such as cakes, biscuits and sweets;
- reduce your salt intake – the recommended daily maximum is 6g;
- drink less alcohol;
- steam cook vegetables to retain the vitamins;
- use olive oil instead of lard or butter to cook with.
Under eating or not consuming enough vitamins and nutrients is also bad for your health and can lead to malnutrition or eating disorders.
RDA stands for Recommended Daily Allowance.
Vitamin A (and beta-carotene)
- European RDA is 800 micrograms.
- Good for eyesight, growth, appetite and taste.
- Food sources include liver, fish-liver oil, carrots, green leafy vegetables, egg yolks, milk products, yellow fruit.
Vitamin B1 (Thiamin)
- European RDA is 1.4 mg
- Good for nervous system, digestion, muscles, heart, alcohol-damaged nerve tissues.
- Food sources include liver, yeast, rice, wholemeal products, peanuts, pork, milk.
Vitamin B2 (Riboflavin)
- European RDA is 1.6 mg
- Good for growth, skin, nails, hair, eyesight
- Food sources include milk, liver, yeast, cheese, green leafy vegetables, fish.
Niacin (formerly known as B3)
- European RDA is 18 mg.
- Good for converting food into energy, building red blood cells.
- Food sources include liver, whole grains, eggs, avocado, peanuts, fish, meat.
Pantothenic acid (formerly known as B5)
- European RDA is 6 mg.
- Good for converting food into energy, natural anti-stress remedy, fatigue, allergies, asthma, psoriasis.
- Food sources include fresh fish, liver and chicken, mushrooms, cauliflower and potatoes, whole grains, yeast, dried beans and peas, avocado, oranges and bananas, peanuts, pecans and hazelnuts, milk, cheese and eggs.
Vitamin B6 (Pyridoxine)
- European RDA is 2 mg.
- Good for preventing skin conditions, nerve problems, protein and carbohydrate absorption.
- Food sources include fish, bananas, chicken, pork, whole grains, dried beans.
Biotin (formerly known as B8)
- European RDA is 150 micrograms.
Folate, folacin, folic acid (formerly known as B9)
- European RDA is 200 micrograms.
- Good for production of red blood cells, and preventing birth defects.
- Food sources include carrots, yeast, liver, egg yolks, melon, apricots, pumpkin, avocado, beans, rye and whole wheat, green leafy vegetables.
Vitamin B12 (Colbalamin)
- European RDA is 1 microgram.
- Good for making red blood cells, formation of the nerves.
- Food sources include fish, liver, beef, pork, milk, cheese and eggs. Vegans are recommended to ensure their diet includes foods fortified with vitamin B12. A range of B12 fortified foods are available. These include yeast extracts, soya milks, vegetable and sunflower margarines, and breakfast cereals.
Vitamin C (Ascorbic acid)
- European RDA is 60 mg.
- Good for immune system, protection against viruses and bacteria, healing wounds, reducing cholesterol, cell lifespan, preventing scurvy. Also a natural laxative.
- Food sources include citrus fruit especially kiwi, berries, tomatoes, cauliflower, potatoes, green leafy vegetables, peppers.
Vitamin D (Calciferol)
- European RDA is 5 micrograms.
- Good for bones and teeth.
- Food sources include cod-liver oil, sardines, herring, salmon, tuna, milk, sunlight.
Vitamin E (Tochopherol)
- European RDA is 10 mg.
- Good for anti-oxidant properties.
- Food sources include nuts, soya beans, vegetable oil, broccoli, sprouts, spinach, wholemeal products, eggs.
Vitamin K (Phylloquinone)
- No European RDA.
- Good for blood clotting and bones.
- Food sources include liver, egg yolk, cheese, broccoli, leafy green vegetables.
The Department of Health also recommends that everyone in the UK should eat at least five portions of fruit and vegetables per day.
Some very simple changes can be made that will lead to a healthier and more balanced diet with little effort required. Generally, achieving a balanced diet will mean taking the following steps:
- Eating more starchy foods. Starch is a good energy provider and adding it to a daily diet can help to reduce fat intake and increase fibre. Starch can be found in foods such as bread, potatoes, rice and pasta.
- Eating more fruit and vegetables. Fruit and vegetables contain a large amount of the vitamins and minerals the body needs to function at its best. They are also very low in fat and are therefore helpful to those trying to lose weight. Specific fruits and vegetables have many other healthy properties and contain specific nutrients. The Department of Health recommends that both adults and children eat at least five portions of fruit and vegetables per day. A new 5-a-day logo can now be found on food products to guide consumers.
- Reducing fat intake. Saturated fat is unhealthy in large quantities. It can raise cholesterol levels in the blood and lead to heart disease. Fat intake can be reduced without too much effort by choosing leaner cuts of meat and lower fat varieties of food. For example, low fat spread contains less fat than butter and skimmed or semi-skimmed milk is healthier than whole fat milk.
- Reducing salt intake. Chose foods with ‘reduced salt’ or ‘no added salt’. Tinned fish, vegetables and pulses are often in salted water, so it is a good idea to wash them before use. Try adding other seasonings such as herbs, spices, garlic and lemon juice to food, for flavour. Sodium content, rather than salt, is usually listed on the nutritional information of most foods. A lot of salt is more than 1.25g (0.5g sodium) per 100g.
- Drinking less alcohol. The British Nutrition Foundation advise men to consume under four units of alcohol per day, and women to stick to less than three units per day. Excess drinking can increase the risk of some cancers, heart and liver disease. It may also lead to obesity and accidents. One unit of alcohol is a single 25ml measure of spirit, a small glass of medium strength wine or half a pint of lager.
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