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It is not possible to be allergic to sugar...

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Carb Facts

Is it possible to be allergic to sugar?

It is not possible to be allergic to sugar. This is a good thing because if someone were allergic to sugar, they would be unable to eat a huge number of foods, including most fruit and vegetables!

Food allergies of any kind should only be diagnosed by properly trained medical staff.

For more information on allergies, go to the British Allergy Foundation's web site.

Doesn't sugar cause diabetes?

Diabetes is a disease caused by inadequate production, or complete lack, of the hormone insulin. Obesity has been highlighted as a major risk factor in diabetes development and over 80% of people with Type 2 diabetes (the most common type) are overweight. It is certainly not caused by eating too much sugar. Eating a healthy, balanced, low-fat, diet and increasing physical activity will help to prevent excessive weight gain.

Insulin is one of the hormones the body needs to keep blood sugar (glucose) levels within the narrow range required for good health. In most people, when food is consumed, blood glucose levels rise and insulin is produced to bring them back down. In people with diabetes, this insulin response is defective and, if not treated, blood glucose levels become dangerously high.

For many years, people with diabetes were told to avoid sugar. However, modern scientific research has shown that people with diabetes can include moderate amounts of sugar in their diet as part of mixed meals, without compromising blood glucose control.

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But isn't sugar just 'empty calories'? If I eat a lot of sugar, how will I get enough vitamins and minerals?

People rarely eat sugar on its own. Adding sugar to foods improves their taste and increases the range of foods that people will eat. For example, without sugar many breakfast cereals, which provide important vitamins, minerals and fibre, would be less palatable.

There is no clear scientific evidence that eating higher levels of added sugar will lead to a lower vitamin and mineral intake.

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Does eating too much sugar cause hyperactivity in children?

In the 1970s it was suggested that hyperactivity in children (also known as Attention Deficit Hyperactivity Disorder or ADHD) was caused by eating too much sugar. Detailed studies, however, have concluded that there is no link between sugar consumption and hyperactivity.  Sugar can be included as part of a healthy, balanced diet and it is not possible to be 'allergic' or 'sensitive' to sugar.

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Will eating sugar, and other carbohydrates, give me 'Syndrome X' or the Metabolic Syndrome?

Eating sugar or other carbohydrates will not give you 'Syndrome X'. It is caused, in the majority of people, by over-eating and an unbalanced diet, especially too much saturated fat, and by not getting enough exercise.

'Syndrome X', or the metabolic syndrome as it is also called, is the term applied to a collection of abnormalities in body function. These include resistance to the action of the hormone insulin, fat accumulated around the waist (central obesity) and increases in other risk factors for coronary heart disease development, for example, increased levels of fats in the bloodstream and raised blood pressure. Although a number of these abnormalities will be present in affected patients, the same symptoms may not be present in everyone, for example not all patients will have insulin resistance.

Taking regular exercise, such as brisk walking, and consuming a healthy balanced diet, low in saturated fat, will improve your fitness levels and your general health, and help to prevent the development of this syndrome and its complications.

Further Reading

Aren't naturally occurring sugars healthier than added sugar?

There are many different types of sugar, including glucose (dextrose), fructose, sucrose (table sugar), lactose (milk sugar) and maltose. All these sugars occur naturally, and all are added to certain foods during manufacture.

Most fruit and vegetables contain a mixture of glucose, fructose and sucrose.


Glucose Content (g/100g)

Fructose content (g/100g)

Sucrose content (g/100g)

Carrots (raw)
Peas (raw)

Source: Food Standards Agency (2002) McCance and Widdowson's The Composition of Foods, Sixth Summary Edition. Cambridge: Royal Society of Chemistry

Different sugars have different properties, but these properties are the same whether they are already present in food or have been added during preparation, cooking or at the table.

There is no difference between the sucrose in a banana, the sucrose in a cake, or the sucrose added to a cup of tea.

Further Reading

Won't eating sugar make me fat?

Sugar is a carbohydrate and provides energy.  Eating carbohydrates, particularly from starchy sources, and taking part in regular physical activity is the healthiest way to maintain a desirable body weight.

Sugar and weight gain

Overweight and obesity occur only when there is an imbalance between the amount of energy taken into the body, as food, and the amount the body needs for normal metabolism and for physical work. Body weight will increase whenever too much food energy is consumed and will decrease whenever the energy intake is less than needed. It has been shown that it is more difficult to overeat on a high carbohydrate diet, because carbohydrate-rich foods fill you up so you are likely to stop eating when you have had enough. High fat foods take much longer to fill you up so it is a lot easier to eat too many calories if your diet is high in fat. High fat foods are also the most concentrated form of energy.

It is also worth remembering that 1 gram of carbohydrate provides only 4 calories whereas 1 gram of fat provides 9 calories.

The sugar-fat seesaw

Current research has shown that people who consume a diet higher in sugar tend to consume lower amounts of fat and vice-versa.  This is known as the 'sugar-fat seesaw.

So if you want to manage your weight, make sure you have an active lifestyle and don't be afraid to enjoy sweet foods as part of a balanced diet rich in fruit and vegetables. But don't forget: if you eat too much you may put on weight. Whatever the source of food energy, protein, carbohydrate or fat, once eaten, the body sees all calories as much the same, and stores any surplus as body fat.

Further Reading

What about soft drinks – don't they make you fat?

Many people believe that soft drinks are particularly "fattening" but the evidence is not at all clear. Some research suggests that it may be easier to take in a few extra calories in a drink than as solid food but, even if this is correct, there seems to be no difference between soft drinks and other liquids, such as milk or fruit juice.

Soft drinks and weight gain

The result of research into the influence of soft drinks on body weight has, so far, been inconclusive. People who regularly consume sugar-containing soft drinks are no more likely to be overweight than people who choose low-calorie versions. If, as is thought likely, weight gain is encouraged by diets that are high in energy but low in bulk (ie high energy density) then soft drinks would not be expected to be important, since they are substantially lower in energy density than many foods.


Further Reading

Will eating sugar give me spots?

Sugar will not give you spots, no matter how much you eat. People get spots, or acne vulgaris, because their skin produces too much natural oil, or sebum. Various foods, including dairy products, sugar and chocolate, have been claimed to cause spots, however, there is no evidence that diet has any effect on sebum production rates.

There is no justification for telling people to avoid specific foods, including sugar, to clear their acne. Following this advice will not help to clear acne.

But doesn't sugar usually come with fat?

The main sources of fat in the British diet are meat products, dairy products and fat spreads (butter and margarine). These foods contain very little sugar.

In contrast, the main sources of sugar in the British diet are soft drinks, confectionery, preserves, biscuits and cakes.

Dietary surveys consistently show that people who obtain a lot of their calories from sugar obtain fewer calories from fat than people who do not eat much sugar. This is known as the 'sugar-fat see-saw'.  Biscuits, cakes, pastries and chocolate, popular foods to contain both sugar and fat, provide only 15% of calories eaten by British children, and even fewer of those eaten by adults.

Further Reading

Doesn't eating sugary foods cause a rush in blood sugar, followed by a low?

Many people think that eating sugary foods causes a dramatic rise in blood sugar followed by a crash, which causes tiredness and food cravings.

This is not true. In fact, in healthy people, blood sugar levels are kept within a narrow range, and tiredness and food cravings are very rarely due to low blood sugar.

People are often surprised to learn that eating table sugar (sucrose) actually causes a smaller increase in blood sugar than eating starchy foods such as baked potatoes and white or wholemeal bread. For this reason sugar is nowadays accepted as part of a balanced diet for people with diabetes.

Further Reading

Doesn't sugar rot your teeth?

Frequent intakes of foods or drinks containing carbohydrates such as sugars can cause tooth decay, especially in people who do not brush their teeth twice a day with fluoride toothpaste.

Bacteria in the mouth use sugars from the diet and from the breakdown of starch to provide energy. This process produces acid that attacks the tooth surface, removing minerals from the teeth (demineralisation). After a short time, the acid in the mouth is neutralised by saliva. The minerals lost from the teeth can then be replaced (remineralisation).

Tooth decay (dental caries) occurs when more minerals are removed from the teeth by bacterial acids than can be replaced from the saliva. This has been found to occur when people eat carbohydrate-containing foods or drinks too frequently. You should try to eat no more than 5 times a day, eg 3 main meals and 2 snacks, and consume all carbohydrate-containing foods, soft drinks and fruit juices on these occasions. In between meals the only drink that is completely safe for teeth is water.

Rates of tooth decay have fallen dramatically over the past 20 years. The best way to prevent tooth decay is to brush your teeth with fluoride toothpaste, twice a day, especially before going to bed, as saliva production is much lower during sleep. Never eat or drink anything except water in bed. Attend regular dental check-ups as advised by your dentist so that any tooth decay can be spotted early on.  Your dentist can also advise you whether you are cleaning your teeth properly.


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Eating a healthy, balanced diet along with taking regular exercise is key to physical and mental wellbeing.

No foods should be considered as ‘good or bad’ as all foods play an important role in the diet. It is only when foods are eaten in excess that health problems result.

Read more about eating healthy