We look at the five major food groups, which foods belong to each and why, what good they do you and how much of each you should be eating every day.
Starchy foods
Fats and sugars
Fruit and vegetables
Protein
Milk and dairy products
Salt
Alcohol
Caffeine
Fluids
Refined and unrefined grains
The foods listed above (apart from potatoes) are all produced from grains, such as wheat, corn or rice. They should be a part of all meals, filling about a third of your plate. They can come in two forms – refined or unrefined (often known as whole grains).
Refined grains have been stripped of their outer bran coating and inner germ during the milling process, leaving only the endosperm. They include white rice, white bread and white pasta.
In a whole grain the bran, germ and endosperm are all still present. The bran is an excellent source of fibre; the germ is a source of protein, vitamins and minerals; and the endosperm supplies most of the carbohydrates, mainly in the form of starch. Unrefined or whole grain forms provide far more nutrients than their refined counterparts.
Whole grains are rich in phytochemicals and antioxidants, which help to protect against coronary heart disease, certain cancers, and diabetes. Studies have shown people who eat more whole grains tend to have a healthier heart.
Most people get their whole grain from wholemeal bread or whole grain breakfast cereals such as porridge, muesli or whole wheat cereals. Choose a whole grain variety over processed or refined grains, and look out for added sugar or salt.
Other whole grains include:
- Wheat
- Oats
- Maize
- Barley
- Rye
- Millet
- Quinoa
- Wild rice
Fibre
Dietary fibre is found in plant foods (fruit, vegetables and whole grains) and is essential for maintaining a healthy digestive system. Fibre cannot be fully digested and is often called bulk or roughage. The two types of fibre found in food are soluble and insoluble.
Soluble fibre, which can dissolve in water, is found in beans, fruit and oat products, and can help to lower blood fats and maintain blood sugar.
Insoluble fibre cannot dissolve in water, so passes directly through the digestive system. It’s found in whole grain products and vegetables and it increases the rate at which food passes through the gut.
Evidence for health benefits of fibre
- High-fibre foods take longer to digest, so keep you feeling fuller for longer. The slow and steady digestion of food through the gut helps control blood sugar and assists with weight maintenance
- Fibre helps in the digestive process and can help lower blood cholesterol
- Fibre promotes bowel regularity and keeping the gastrointestinal tract clean to help reduce the risk of developing diverticular disease and constipation
- A high-fibre diet may reduce the risk of developing diabetesand colorectal cancer
How much is enough?
Bread, rice, potatoes, pasta and other starchy foods should make up about one third of your diet. Try these recipes from the BBC Food website:
- Banana and Oat Smoothie
- Wholemeal pizza baguettes
- Ham and watercress sandwich on wholemeal bread
- Creamy lentils and brown rice
- Using wholemeal flour in baking, as in this Irish Soda Bread or half and half as in these
What about GI?
The glycaemic index (GI) is a way of ranking carbohydrate foods based on how quickly they increase blood sugar levels. Low GI foods are especially helpful for people with diabetes, who need to have more control over their blood sugar levels than the general population.
Ideally foods with a low GI, such as those rich in soluble fibre like oats and legumes, should be eaten more frequently than those with a high GI. But the texture, type of cooking or processing used, and the amount and type of sugars present can all affect the GI. Since foods are often consumed as part of a meal or snack, it can be difficult to calculate the GI. Focusing on unrefined, high-fibre, whole grain cereals and minimising rapidly absorbed, refined cereals and sugary foods will all help to lower the GI of your diet.
Fat facts
- Fat transports the fat-soluble vitamins A, D, E and K around the body
- It can often improve the flavour and perception of foods, increasing their palatability
- It supplies essential nutrients such as fat-soluble vitamins and essential fatty acids (EFAs)
- EFAs must be supplied from the diet, and are thought to have a positive effect on heart health and the immune system
- It has a key role in membrane structure
- It cushions, and so protects, the internal organs
- It's stored in adipose tissue (a thick layer of tissue under the skin) as a long-term fuel reserve. Excess fat may also accumulate around your organs, especially in the abdominal cavity
Fat is a concentrated source of energy. Just 1g provides nine calories - more than double the calories in 1g of protein or carbohydrate.
This means it's much easier to consume too many calories when eating high-fat foods. People trying to manage their weight should reduce fatty foods to help cut calories. We all need some fat in our diets, but small quantities of EFAs are the key to good health.
The two types of fat
Fat can be divided into two main groups - saturated and unsaturated.
Saturated fat is generally solid at room temperature and is usually from animal sources. It's found in lard, butter, hard margarine, cheese, whole milk and anything that contains these ingredients, such as cakes, chocolate, biscuits, pies and pastries. It's also the white fat you can see on red meat and underneath poultry skin.
The vaue of saturated and unsaturated fat in our diets isn’t fully understood yet but generally, eating too much saturated fat is associated with increased blood cholesterol concentrations and an increased risk of heart disease. Eating less helps to minimise the risks it poses to heart health. Polyunsaturated fats contain inflammatory omega-6 fatty acids and it’s the balance of these with omega-3s which is important.
Trans fats, or hydrogenated unsaturated fats, are used in the food industry but are increasingly recognised as being unhealthy.
Unsaturated fat is usually liquid at room temperature and generally comes from vegetable sources. Monounsaturated and polyunsaturated fats are both included in this group. Unsaturated vegetable oils are generally a healthier alternative to saturated fat and can be found in sesame, sunflower, soya and olive oil, soft margarine and in foods such as oily fish, including mackerel, sardines, pilchards and salmon. Where possible, you should ensure the fat you eat is unsaturated.
Did you know...?- A jam doughnut contains 10.9g fat
- A slice of malt loaf contains 0.7g fat
- A teaspoon of peanut butter contains 5.4g fat
- A pint of whole milk contains 22.8 g fat
- A handful of mixed nuts contains 21.6g fat
How much is enough?
Government guidelines recommend fats make up no more than 35 per cent of the energy in your diet, and that saturated fats should provide less than 11 per cent of total energy intake.
For the average woman, this means about 70g of total fat a day; for men, roughly 95g.
The latest National Diet and Nutrition Survey showed that, on average, UK adults consume about the right amount of fat, but that the intake of saturated fats is currently too high for good health (at present they provide about 13 per cent of total energy).
To reduce the amount of fat in your diet, try the following:
- Look for alternatives to cakes, biscuits and savoury snacks, which are often high in fat - try fresh fruit, dried fruit and cereal-based products
- Trim any visible fat off meat and poultry
- Buy lean cuts of meat and reduced-fat minces
- Poach, steam, grill or bake food rather than fry it
- Swap whole milk for semi-skimmed or skimmed
- Opt for low-fat dairy products
- If you use lard, butter or hard margarine, switch to vegetable oil and low-fat spreads
Sugary foods
There are two types of sugar - those found naturally in fruit and milk (which are fine and don't need to be cut down) and those that are added to the diet.
These added sugars can be found in a variety of foods including confectionery, soft drinks, desserts and breakfast cereals. Added sugars are a great source of energy, but provide no other nutrients.
Sugary foods and drinks pose a threat to dental health, especially if consumed between meals.
Even the sugars in honey and fruit juices can cause tooth decay if good oral hygiene isn't followed and you consume a lot of these foods.
Only have sugary foods at mealtimes, when other dietary and oral factors can help to minimise the risk they pose to your teeth.
Sugary drinks have been identified as a possible cause of obesity. These drinks do not trigger the same sense of fullness as food with similar calories, increasing the risk of overeating.
How to reduce consumption of sugary foods
- Swap sugary drinks for water, low-fat milk or artificially sweetened drinks to reduce your calorie intake
- Try swapping sugary snacks for fruit or bread-based options such as fresh whole fruit or teacakes/malt loaf
- Try to halve the amount of sugar you put in hot drinks, or cut it out completely
- Buy reduced-sugar varieties of jam and marmalade
- Choose tinned fruit in natural juice rather than syrup
Fruit and vegetables
Five a day
Due to their nutritional and health benefits, it's recommended that fruit and vegetables form the basis of your diet, with a minimum intake of five portions each day - about a third of your daily food consumption. Currently the UK averages two to three portions a day, so we're falling well short of the benefits they can provide.
Fruit and vegetables should be incorporated into every meal, as well as being the first choice for a snack. Population studies have shown that people who eat a lot of fruit and vegetables may have a lower risk of chronic disease, such as heart diseaseand some cancers. Health benefits can be gained from fresh, tinned (in natural juice), frozen, cooked, juiced or dried versions. Potatoes don't count though, as they're a starchy food.
How much is a portion?
- One piece of medium-sized fruit, such as an apple, peach, banana or orange
- One slice of fruit, such as melon, mango or pineapple
- One handful of grapes or two handfuls of cherries or berry fruits
- One tablespoon of dried fruit
- A glass (roughly 100ml) of fruit or vegetable juice
- A small tin (roughly 200g) of fruit
- 3 tablespoons of fruit salad or stewed fruit
- A side salad
- A serving (roughly 80g) of vegetables, such as frozen or mushy peas, boiled carrots or stir-fried broccoli
- Cooked dishes that contain significant amounts of vegetables may also count
So how do you ensure an intake of five portions a day? Here's a typical plan:
- Glass of fresh orange juice or smoothie for breakfast = one portion
- Small pack of dried apricots for mid-morning snack = one portion
- Side salad with lunch = one portion
- Sugar snap peas and broccoli, served with main meal = one portion
- Strawberries as dessert = one portion
Do remember that some fruits contain many of their nutrients just under the skin, so eating them with the skin on can provide greater nutritional benefits and the maximum amount of fibre compared with just drinking the juice of the same fruit.
Why are they important?
Fruit and vegetables of differing colours contain diverse mixtures of phytonutrients (protective plant compounds). These can act as powerful antioxidants, protecting the body from harmful free radicals and helping to protect against certain chronic diseases such as cancer. Some fruit and vegetables are labelled as 'superfoods' because they contain high concentrations of some phytonutrients, particularly antioxidants, which appear to be beneficial to health.
- Blueberries - contain flavonoids that can improve circulation and help defend against infection
- Broccoli - rich in the antioxidants vitamin C and beta-carotene, as well as folate, all of which can protect against cardiovascular disease and cancer
- Tomatoes - rich in lycopene, a powerful antioxidant that can protect against harmful free radicals
- Linseeds - rich in omega-3 fatty acids, which may help control cholesterol levels
But variety is the key. In addition to these phytonutrients, each variety of fruit and vegetables contains its own combination ofvitamins, minerals and fibre. Choosing a variety throughout the day will provide a diverse package of essential nutrients.
Boiled or steamed?
Although fruit and vegetables are packed with vitamins and minerals, many of these essential nutrients can be easily destroyed by heat when cooking and during food preparation.Water-soluble vitamins are especially vulnerable when boiled. One solution is to eat raw vegetables as much as possible, such as raw carrot, celery or peppers.
When cooking vegetables, try steaming, microwaving or poaching rather than boiling. These methods do not involve immersing them in water, so the maximum amount of nutrients can be retained, as well as their fresh taste. If you prefer to boil vegetables, do so for the minimum amount of time and in as little liquid as possible in order to retain their valuable nutrients. You could also utilise the water used in another part of your dish, such as gravies or stocks, to recapture some of the leached nutrients.
Fibre for weight control?
Fruit and vegetables are important contributors to the intake ofdietary fibre, both soluble and insoluble. Fibre is slowly digested and has a low Glycaemic Index (GI). This means glucose will be released steadily into the body over several hours, allowing you to feel fuller for longer, compared with high GI foods that produce a rapid rise followed by a subsequent fall in blood sugar, often leaving you hungry soon after you've eaten. This feeling of fullness produced by the fibre within fruit and vegetables can therefore help with weight control. Fruit and vegetables also assist weight management as they're low in calories, but remember that their calorific load is determined by what you prepare them with, so avoid the butter, cream or cheese sauces, and dips that can accompany them.
Protein
Why is protein important?
From hair to fingernails, protein is a major functional and structural component of all our cells. Protein provides the body with roughly 10 to 15 per cent of its dietary energy, and is needed for growth and repair.
Proteins are large molecules made up of long chains of amino acid subunits. Some of these amino acids are nutritionally essential as they cannot be made or stored within the body and so must come from foods in our daily diet.
Although all animal and plant cells contain some protein, the amount and quality of this protein can vary widely.
Animal protein
Protein from animal sources contains the full range of essential amino acids needed from an adult's diet. But red meat, in particular, should be eaten in limited amounts due to the high level of saturated fat it contains, which may raise blood levels of 'unhealthy' LDL cholesterol.
A high intake of saturated fat can lead to an increased risk of cardiovascular disease and other related disorders. As an alternative source of animal protein, choose poultry, fish and shellfish.
The 2007 World Cancer Research Fund report recommended meat eaters limit their consumption of red meat to no more than 500g a week, with very little processed meat, as these have both been linked to certain forms of cancer.
Fish is a good source of animal protein. Oil-rich fish such as salmon, mackerel, herring, tuna, trout and sardines are all rich in omega-3 fatty acids, which help to reduce the risk of developing cardiovascular disease.
Shellfish is also a good source of protein and is low in fat.
Aim to eat a couple of portions of fish every week, with at least one portion being an oily fish.
Did you know...?Eggs contain all eight essential amino acids, making them a perfect source of protein. However, you'd have to eat at least eight eggs a day to get all the protein you need. Be sensible; include them as part of a balanced and varied diet.
Advice for vegans and vegetarians
Vegetarians rely on plant sources for their daily protein. Plants don’t contain the full range of essential amino acids and so are not as high in nutritional value as animal protein. But by eating a well-balanced diet that contains a variety of different foods, it's possible to consume the required amino acids, regardless of the time of day they’re eaten or in what combinations within a meal.
Foods such as nuts, seeds, beans, pulses, vegetable protein foods and soya products all contain protein. There are also small amounts in grains and dairy products. Due to this variety of protein-rich foods available in the UK, protein deficiency is rare.
How much is enough?
Health professionals suggest men should eat 55.5g protein a day and women 45g. In practical terms, eating a moderate amount of protein - in one or two meals every day – should give you all the protein you need. Most people in the UK eat far more protein than they actually need.
Serving size
You should eat two to three servings of protein every day from both plant and animal sources. Here are some examples of one serving (about the size of a standard pack of playing cards):
- 100g boneless meat (eg lean beef, lamb or pork)
- 100g boneless poultry (eg chicken or turkey breast)
- 100g fish (eg salmon, sardines or tuna)
- 2 medium eggs
- 3 tablespoons of seeds (eg sunflower or pumpkin seeds)
- 3 tablespoons of nuts (eg almonds or walnuts)
Choosing the right protein
If you can, choose to eat low-fat protein foods as these will help to:
- Keep your heart healthy
- Keep cholesterol low
- Minimise the risk of developing cardiovascular disease and other related disorders
Use this table to choose foods rich in protein but low in saturated fat.
[an error occurred while processing this directive]Protein and weight management
High-protein diets are sometimes popular with people wanting to lose weight, and there have been many studies looking at the effect of such diets on weight loss.
Regardless of the composition of the diet, weight loss will only occur if you expend more energy through activity than your body produces from food.
Protein-rich foods tend to make people feel fuller than foods rich in carbohydrates or fat. This can have a knock-on effect on appetite, minimising feelings of hunger, and helping to reduce overall energy intake.
Diets rich in protein at the expense of carbohydrates, for example, have been associated with slightly greater losses of weight in the short term compared with the recommended high-carbohydrate, low-fat eating plans. But after one year, studies have found there is no difference in weight loss between the two diets.
To control your weight it's important to find an eating pattern that suits your lifestyle and that you can sustain over a long period.
Milk and dairy products
Varieties of milk
Supermarkets now stock many different varieties of milk. The most common in the UK is still cow's milk, but others include sheep and goat's milk, as well as a number of plant-based substitutes - including soya, rice, oat and almond milk - for those with lactose intolerance.
Milk in the UK (generally cow's milk) is distinguishable by its fat content.
- Whole or full-fat milk contains about 3.5 per cent fat
- Semi-skimmed contains about 1.7 per cent fat
- Skimmed milk contains 0.1 to 0.3 per cent fat
Even whole milk is relatively low in fat and certainly semi-skimmed milk can be labelled as a low-fat food. Contrary to popular belief, lowering the fat content in milk does not affect the calcium content, so an adequate calcium intake can still be obtained from lower-fat dairy products. However, low fat milk contains less energy and lower amounts of fat soluble vitaminsand isn't suitable for children under two years.
Some supermarkets have now started selling milk with a 1 per cent fat content which has almost half the fat of semi-skimmed milk but retains a more creamy flavour. This is a good option for those people who want to lower the amount of fat they're consuming but don’t like the taste of skimmed milk.
Milk products
Cheese contains the same beneficial nutrients as milk, but most cheeses contain much more saturated fat and high levels of added salt, so it's important to only eat full-fat cheese occasionally and in small portions.
Yoghurt is rich in protein and vitamin B2: essentially the same nutrients as in milk. Some varieties contain living bacteria that are healthy for your digestive system (probiotics). Yoghurt can be made from whole or low fat milk, but be careful. Fruit yoghurts often contain added sugar. Low fat doesn't necessarily mean low calories. If you're watching your weight, look for 'diet' versions, or make your own by mixing fruit with natural, low fat, unsweetened yoghurt. Check out the labels of packs for details.
The importance of calcium
Calcium is a mineral that helps build strong bones and teeth, regulates muscle contraction (including the heartbeat) and makes sure the blood is clotting normally. Milk and dairy products have long been held as an important source of calcium, although more recently the role and safety of dairy calcium sources have been questioned by some scientists and more research is needed to draw a firm conclusion.
Other sources of calcium include:
- Fish (for example sardines)
- Dried fruit
- Sesame seeds
- Almonds
- Soya
- Dark green leafy vegetables
More importantly, research also suggests that calcium in your diet is less important in developing healthy bones than vitamin D (from your daily diet or from the sun's effect on the skin). Similarly, sufficient exercise is now seen as another vital factor in maintaining healthy bone structure and density - concerns have been voiced that a lack of excercise in growing children will have a detrimental effect on their bones.
Calcium can continue strengthening your bones until the age of 20 to 25 when peak bone mass is reached. After this point, your bones can only maintain or lose their density and grow weaker as a natural part of the ageing process. Inadequate dietary calcium intake before this age can increase the risk of brittle bone disease and osteoporosis, as calcium is drawn from the bones as a reserve.
Each year in the UK, over £1.7 billion is spent on treatingosteoporosis. Health professionals estimate that one in two women and one in five men over the age of 50 in the UK will break a bone, mainly because of osteoporosis. Women are more affected as they have less bone mass than men, and may lose it faster as they get older, especially after the menopause when falling oestrogen levels result in the loss of the protective effect of oestrogen on bone density.
Why children need calcium
Calcium is an essential nutrient for all children to help grow strong bones and reduce the risk of developing osteoporosis when they're older. But many children and teenagers don't receive their recommended daily intake. Encouraging children and adolescents to drink more milk, rather than other drinks, can provide not only calcium, but also important proteins, carbohydrates and micronutrients.
Daily recommendations for calcium intake in children:
[an error occurred while processing this directive]Calcium for vegans and the lactose intolerant
If your diet excludes milk and dairy products, or if you can't tolerate milk sugar lactose, then you need to look for calcium alternatives. Other dietary sources of the mineral include:
- calcium-enriched soya milks, yoghurts and cheeses
- dark green leafy vegetables, such as spinach, broccoli and watercress
- almonds or sesame seeds – try as a topping on salads, cereals or desserts
- dried fruits - apricots, dates and figs all contain small amounts of calcium
- (for non vegans) fish such as sardines and anchovies, especially the bones
Three-a-day
As dairy products are such a rich source of calcium, three portions of dairy products each day should be sufficient to meet your body's calcium needs. Try to choose low or reduced fat versions to avoid too much unhealthy saturated fat.
The following are examples of individual servings:
- 200ml milk (whether it is whole or full-fat, semi-skimmed or skimmed)
- 250ml calcium-fortified soya milk
- 40g hard cheese (such as cheddar, brie, feta, mozzarella or stilton)
- 125g soft cheese (such as cottage cheese or fromage frais)
- 1 small pot of low-fat plain or fruit yoghurt (150g)
- Fruit smoothie made with 200ml milk or 150g yoghurt
Salt
Daily requirements
Sodium, unlike all other minerals, is generally overconsumed, with the dietary intake of salt in the UK being far in excess of the recommended daily requirement.
Adults are advised to consume no more than 6g salt per day (about one teaspoon). Current intake is about 9g per day - thats 50 per cent higher than is recommended for good health. Babies and children should have less salt than adults. High salt intake in babies can be especially dangerous, as their kidneys cannot cope with large amounts. Recommendations for babies and children are given below:
[an error occurred while processing this directive]Reducing salt intake
The government has set a target of reducing the average salt consumption of adults to 6g per day by 2010. This is a challenging but achievable goal, which will bring measurable improvements in health. A study published in the scientific journal Hypertension in 2003 estimated that a reduction in salt intake to 6g per day would lead to a 13 per cent reduction in stroke and a 10 per cent reduction in ischaemic heart disease.
People who have experienced heart problems or have high blood pressure should follow a low-salt diet and take advice from their health care professional. Reducing sodium has been proven to be one of the best ways of lowering high blood pressure, especially in combination with broader dietary changes.
How to reduce sodium intake
Convenience foods, ready meals and canned foods, as well as eating out frequently, all contribute to a higher sodium intake, so read labels carefully to compare foods and opt for those lower in salt. Some labels provide both the salt and the sodium content within the product. This can be confusing, as the two are not interchangeable - 1g of salt contains 0.4g sodium (remember salt is made up of sodium AND chloride).
[an error occurred while processing this directive]If you're checking labels, here's a guide based on 100g/ml of product:
- A lot of salt = 1.25g salt (or 0.5g sodium) - would be labelled as red on a traffic light labelling system
- A little salt = 0.25g salt (0.1g sodium) - would be labelled as green on a traffic light labelling system
- Anything in-between these figures indicates a moderate amount of salt
More ways to reduce salt intake:
- Use fresh or dried herbs and spices to flavour vegetables
- Avoid adding salt to your food when eating
- Use soy sauce sparingly: one teaspoon contains about 0.36gof sodium (equivalent to 0.9g salt)
- Buy fresh or frozen vegetables, or those canned without salt
- Rinse canned foods, such as beans, to remove excess salt
- Choose breakfast cereals that are lower in sodium
- Buy low or reduced sodium versions, or those with no salt added
Too much salt
Symptoms of increased salt intake include nausea, vomiting, diarrhoea and abdominal cramps. High concentrations of sodium in the body can also result from excessive water or fluid loss. Persistently high levels of sodium in the blood can result in swelling, high blood pressure, difficulty in breathing, and heart failure, and may be fatal.
A high dietary salt intake is an important causal factor in the development of hypertension (high blood pressure), which currently affects 32 per cent of men and 30 per cent of women in the UK. Hypertension increases the risk of strain on the heart, enlarges the heart muscle, prevents an adequate blood (and therefore oxygen) supply from reaching the heart, and may lead to heart failure, angina or heart attack.
Sodium deficiency
This is rare because our dietary intake is so high, but levels of sodium in the body can become too low as a result of prolonged illness. Sodium levels can also become low due to dehydration or excessive or persistent sweating, which may occur during very hot weather or affect marathon runners, athletes in triathlons, or people with certain forms of kidney disease, such as acute kidney failure.
Symptoms of a deficiency of sodium include headache, nausea and vomiting, muscle cramps, drowsiness, fainting, fatigue and possibly coma.
Salt facts
- More than 90 per cent of sodium occurs as salt.
- More than three quarters of salt intake is derived from processed foods, just under 15 per cent from natural sources, about 10 per cent is added during cooking or when eating, and 1 per cent comes from tap water.
- Cereal products including breakfast cereals, bread, cakes and biscuits provide about a third of the salt in our diet.
- Meat and meat products (such as ham) provide just over a quarter of the salt in our diet.
- In addition to sodium chloride, there is a wide variety of other forms of sodium in our diet, many of which are used as additives in food processing, usually to add flavour, texture or as a preservative. For example, monosodium glutamate is commonly used as a flavour enhancer.
Alcohol
What is alcohol?
Alcohol is a common term for ethanol, a compound produced when glucose is fermented by yeast. The alcohol content of a particular drink is controlled by the amount of yeast and length of fermentation.
Fruit is used to make wine and cider, while cereals such as barley and rye form the basis of beer and spirits.
Alcohol is a drug that has the immediate effect of altering mood. Drinking it makes people feel relaxed, happy and even euphoric, but in fact alcohol is a depressant. It switches off the part of the brain that controls judgement, leading to loss of inhibitions. Drinking even small amounts of alcohol can affect physical coordination.
The liver breaks down and eliminates alcohol from the body. It takes the liver about one hour to deal with one unit of alcohol (8g).
Benefits
Alcohol consumed in moderation is thought to help reduce the risk of heart disease. Indeed, alcohol consumption in conjunction with high intakes of fruit and vegetables may well explain the so-called 'French paradox'. The French diet is considered to be very high in fat, especially saturated fat, yet the death rate from coronary heart disease (CHD) remains relatively low.
A research study published in 1992 suggested that the low death rates from CHD could be due to the relatively high consumption of wine in France. A similar pattern of diet and alcohol consumption has also been found in other south European countries where heart disease rates are also lower compared with other parts of the world.
These observations prompted a long series of research studies analysing the relationship between wine and CHD.
It's still not entirely clear how alcohol reduces your risk of CHD, but it's now known a large proportion of the risk reduction is due to moderate alcohol intake raising 'good' cholesterol concentrations in the blood, so reducing the risk of blood clots.
Red wine, in particular, also contains flavonoids that act as antioxidants, which help to reduce the build up of atherosclerosis (when fat builds up on the inner walls of arteries). Red wine seems to help maintain the flexibility of the blood vessel walls.
Risks
Drinking too much alcohol will not only leave you with a hangover the next day, but binge drinking and/or drinking more than the recommended intake on a regular basis can also cause long-term damage to the body's internal organs.
Chronic alcohol use is one of the major causes of liver cirrhosis (irreversible scarring of the liver). This happens because healthy liver cells die and the dead cells are replaced by fibrous tissue.
The liver plays a central role in many essential body functions including the metabolism of carbohydrates, proteins and fats, detoxification and excretion of waste products from the body. Scarred tissue cannot function like healthy tissue so this condition can be life threatening if not treated early enough.
Stomach ulcers and gastrointestinal complications, as well as fertility problems, weight gain, and depletion of certain vitamins and minerals can all be caused by excessive alcohol consumption.
Binge drinking can also increase blood pressure, a risk factor for heart attacks. One study showed binge-drinking patterns in Northern Ireland at the weekends led to higher blood pressure levels, and a higher incidence of heart attacks on Mondays and Tuesdays. Blood pressure levels in French drinkers were constant throughout the week, reflecting their moderate drinking patterns.
A 2007 World Cancer Research Fund report showed alcohol increases the risk of cancers of the mouth, pharynx, larynx, oesophagus, colon (especially in men) and breast.
If you're worried about the negative effects of alcohol, either on yourself or on behalf of someone else, Alcohol Concern offers an excellent service.
Recommended intake
Moderation is the key. In the UK, the recommendation is no more than two to three units of alcohol a day for women and three to four units for men, with at least two or three alcohol-free days each week.
What's a unit?
One unit is considered to be 8g of alcohol, or equivalent to:
It's important to remember units differ according to the:
- size of your drink - pubs often serve wine in different-sized glasses, and home measures of spirits are often more generous than a pub measure
- varying alcohol content of different beers, wines and spirits
The size and strength of your drink determines how many units of alcohol you consume.
Calculating units
Establish the strength of the drink (% ABV) and amount of liquid in millilitres (one pint is 568ml; a standard glass of wine is 175ml).
Multiply the amount of drink in millilitres by the percentage ABV, and then divide by 1,000.
To make matters easier, many manufacturers state how many units of alcohol each can or bottle contains.
Nutritional value of alcohol
Each gram of alcohol contains seven calories. If you're watching your waistline, cutting down on alcohol will help to reduce calorie intake. Alcohol can also weaken your willpower, tempting you to eat more than you planned.
Alcohol is often referred to as a source of 'empty calories', meaning it has no nutritional value other than providing energy. The energy provided by an alcoholic drink depends on the percentage of alcohol it contains, but also on the type of drink it is. For example, a creamy liqueur will have more calories than a clear liqueur. As a rough guide:
- A pint of continental lager is about 215 calories
- A measure of spirit contains around 55 calories, but this doesn't include calories from the mixer - try to choose low-calorie options
- A standard glass of dry white wine or red wine is about 115 calories, and sweet wine is about 165 calories
- A creamy liqueur contains around 163 calories per 50ml serving, while the same amount of sherry or port contains around 60 calories a glass
Caffeinated drinks
Effects of caffeine
Caffeine acts as a stimulant to the heart and central nervous system, and is also known to increase blood pressure in the short term, although there's no conclusive evidence of long-term effects on blood pressure.
The effects on blood pressure are most likely when caffeine is taken in excessive quantities or by people who are highly sensitive to it. People who are hypertensive (have habitual high blood pressure) are advised to avoid caffeinated drinks, and pregnant women should limit their intake of caffeine to less than 300mg a day.
[an error occurred while processing this directive]Caffeine and weight loss
Caffeine has been shown to have very modest effects on increasing metabolism, and is sometimes added as an ingredient to weight loss pills. These pills often make claims about speeding metabolism to 'effortlessly melt' excess fat, but in reality the amount of calories that slimming pills containing caffeine would actually burn is very small.
Caffeine may also suppress appetite, but without making other changes to your diet and lifestyle caffeine is unlikely to make a significant difference to your weight.
Coffee
Coffee has been linked with a number of the risk factors for coronary heart disease, including increased blood pressure and raised blood cholesterol levels. But no relationship has been found between drinking coffee and the likelihood of developing coronary heart disease.
Coffee may be beneficial in some areas of health - for example, research has found it may reduce the risk of developing gallstones and kidney stones.
It's difficult to suggest a safe limit for coffee intake because of the huge variation in caffeine content across different brands and an individual's sensitivity to the drug. People with high blood pressure and pregnant women are advised to limit their caffeine consumption.
For the rest of the population, there's no evidence coffee does any long-term harm. Caffeine does have a very mild diuretic effect but, drunk in moderation, you don’t need to increase fluid intake to any significant degree as the loss of fluid is very minimal.
Tea
Tea contains some useful minerals such as zinc, manganese and potassium, and scientists are researching its potential to reduce the risk of coronary heart disease and some cancers.
Tea contains antioxidant substances called flavonoids, which have been shown to help slow or inhibit the chemical reactions thought to take place during the development of coronary heart disease.
Green tea
There's also a lot of interest in the health benefits of green tea, particularly in relation to cardiovascular health. Again, this is due to flavonoids, which are powerful antioxidants found in high concentrations in both green and black teas. The concentration of these compounds depends on how long the tea has been brewed, but can range from 125mg to 140mg.
Some studies have compared the concentration of these antioxidant compounds to that found in fruit and vegetables. Flavonoids bring potential benefits to heart health, as well as possible reductions in the risk of Alzheimer’s disease and other neurodegenerative conditions.
Caffeine and iron absorption
Both tea and coffee contain polyphenols that can bind to iron, making it difficult for our bodies to absorb. Avoiding tea and coffee during and around mealtimes is important for people at risk of iron deficiency.
Fluids
Why do we need water?
Water makes up 50 to 70 per cent of an adult's total body weight and, without regular top-ups, our body's survival time is limited to a matter of days.
Water's essential for the body's growth and maintenance, as it's involved in a number of processes. For example, it helps get rid of waste and regulates temperature, and it provides a medium for biological reactions to occur in the body.
Water's lost from the body through urine and sweat, and must be replaced through the diet. If you don't consume enough you can become dehydrated, causing symptoms such as headaches, tiredness and loss of concentration. Chronic dehydration can contribute to a number of health problems such as constipation and kidney stones.
How much water do we need?
The body gets its fluid from three sources:
- Drinks, either plain water or as part of other beverages including tea, coffee and squash
- Solid foods, especially fruit and vegetables (even foods such as bread and cheese provide small amounts of fluid)
- As a by-product of chemical reactions within the body
Most healthy adults need between one and a half to three litres a day, so aim to drink six to eight medium glasses of fluid daily. Beverages such as tea, coffee and fruit juices count towards fluid intake, and may bring with them other nutrients or benefits.
You may require more fluid if you're very physically active or during periods of hot weather.
You can judge whether you're drinking enough by the colour of your urine. If it's a pale straw colour then your fluid intake is probably fine. If your urine is dark yellow, you probably need to drink more.
Bottled water
There are two types: spring water and mineral water.
Spring water is collected directly from the spring where it rises from the ground, and must be bottled at the source. UK sources of spring water must meet certain hygiene standards, and may be further treated so they meet pollution regulations.
Mineral water emerges from under the ground, then flows over rocks before it's collected, resulting in a higher content of various minerals. Unlike spring water, it can't be treated except to remove grit and dirt. Different brands of spring and mineral waters have differing amounts of minerals depending on their source.
Is it necessary to buy bottled water?
The drinking water available from UK taps is perfectly adequate to replenish fluid loss, and undergoes many processes to bring it up to the standards set out in the UK Water Supply Regulations.
In some areas tap water has fluoride added, which can reduce the risk of dental decay.
There are certainly no proven health benefits of bottled water over tap water. Although there are growing concerns about the sustainability of bottled water, ultimately it comes down to personal choice.
