press

"Carb Facts"

Print this page

Allergy | Diabetes | Empty Calories | Hyperactivity | Metabolic Syndrome | Natural | Obesity | Soft Drinks | Spots | Sugar and Fat | Sugar Rush | Tooth Decay

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!

Some alternative/complementary medicine practitioners 'diagnose' an allergy to sugar using tests that may appear scientific but which in fact have no scientific basis whatsoever. Food allergies of any kind should only be diagnosed by properly trained medical staff.

Back to top

 

Doesn't sugar cause diabetes?

dna

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. Indeed, including some sugar in the diet may actually be beneficial to people with diabetes as it makes it easier for them to keep their fat intake down.

Further Reading

  • American Diabetes Association. 2002. Evidence-based nutrition principles and recommendations for the treatment and prevention of diabetes and related complications. Diabetes Care, 25(1), pp202-212.
  • Food and Agriculture Organisation of the United Nations & World Health Organisation. 1998. Carbohydrates in Human Nutrition. Report of a Joint FAO/WHO Expert Consultation. FAO Food & Nutrition Paper 66.  
  • Food and Nutrition Board, Institute of Medicine, National Academy of Sciences. 2002. Dietary reference intakes for energy, carbohydrates, fiber, fat, protein and amino acids. National Academic Press. USA.
  • McClenaghan NH 2005. Determining the relationship between dietary carbohydrate intake and insulin resistance. Nutrition Research Reviews, 18 pp222-240.
  • World Health Organization and Food and Agriculture Organization. 2003. Diet, nutrition and the prevention of chronic diseases. Report of a Joint FAO/WHO Expert Consultation. WHO Technical Report Series 916. WHO Geneva, Switzerland.
  • For further information on diabetes, go to the Diabetes UK website.

Back to top

 

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.

Surveys have shown that vitamin and mineral intakes are rarely lower - in fact, they are often higher - in people who eat the most sugar. In any case, most people in the UK are consuming more than enough vitamins and minerals. Those who are not tend to be people who do not eat enough food overall, or who do not have a sufficiently varied diet.

Further Reading

  • Science Centre article on empty calories.
  • Bolton-Smith C. & Woodward M. 1995. Antioxidant vitamin adequacy in relation to consumption of sugars. European Journal of Clinical Nutrition, 49, pp124-133.
  • Food and Nutrition Board, Institute of Medicine, National Academy of Sciences. 2002. Dietary reference intakes for energy, carbohydrates, fiber, fat, protein and amino acids. National Academic Press. USA.  
  • Forshee R.A. and Storey M.L. 2001. The role of added sugars in the diet quality of children and adolescents. Journal of American College of Nutrition, 20(1), pp32-43.
  • Gibson S.A. 2007. Dietary sugars and micronutrient adequacy: a systematic review of the evidence. Nutrition Research Reviews, 20, pp121-131.
  • Gibson S.A. 1993. Consumption and sources of sugars in the diets of British schoolchildren: Are high-sugar diets inferior? Journal of Human Nutrition and Dietetics, 6, pp355-371.
  • Rennie K.L. and Livingstone M.B.E. 2007. Associations between dietary added sugar intake and micronutrient intake: a systematic review. British Journal of Nutrition, 97, pp832-841.

Back to top

 

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 or any other type of 'bad behaviour' or learning difficulties. Children may become over-excited on occasions where lots of sugary foods are eaten (eg birthday parties) but this is a consequence of the situation, not their sugar intake. Sugar is a normal part of a healthy diet and it is not possible to be 'allergic', 'intolerant' or 'sensitive' to sugar.

Further Reading

  • Science Centre article on hyperactivity.
  • Benton D. 2008. Sucrose and behavioural problems. Journal of Critical Reviews in Food Science, 48(5), pp385-401.
  • Food and Agriculture Organisation of the United Nations & World Health Organisation. 1998. Carbohydrates in Human Nutrition. Report of a Joint FAO/WHO Expert Consultation. FAO Food & Nutrition Paper 66.  
  • Food and Nutrition Board, Institute of Medicine, National Academy of Sciences. 2002. Dietary reference intakes for energy, carbohydrates, fiber, fat, protein and amino acids. National Academic Press. USA.
  • Voltaic M.L., Wilson D.B. & White J.W. 1995. The effect of sugar on behaviour or cognition in children: a meta-analysis. Journal of the American Medical Association, 274(20), pp1617-21.

Back to top

 

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.

cycling

'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

  • Goop L. 2000. Genetics of the metabolic syndrome. British Journal of Nutrition, 83:Suppl 1, ppS39-S48.
  • Hales C.N. and Barker D.J. 2001. The thrifty phenotype hypothesis. British Medical Bulletin, 60, pp5-20.
  • Katzmarzyk P.T., Church T.S., Blair S.N. 2004. Cardiorespiratory fitness attenuates the effects of the Metabolic Syndrome on all-cause and Cardiovascular Disease mortality in men. Archives of Internal Medicine,164, pp1092-1097.
  • Reaven G.M. 1995. Characteristics of Metabolic Syndrome X. Endocrinology and Metabolism, 2(Suppl. B), pp37-42.

Back to top

 

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.

fruit

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

Fruit/Vegetables

Glucose Content (g/100g)

Fructose Content (g/100g)

Sucrose Content (g/100g)

Carrots (Raw)

2.3

1.9

3.2

Peas (Raw)

0.1

0.1

2.1

Apples

1.7

6.2

3.9

Apricots

1.6

0.9

4.6

Bananas

4.8

5.0

11.1

Cherries

5.9

5.3

0.2

Grapes

7.6

7.8

0.1

Oranges

2.2

2.4

3.9

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

  • Food and Agriculture Organisation of the United Nations & World Health Organisation. 1998. Carbohydrates in Human Nutrition. Report of a Joint FAO/WHO Expert Consultation. FAO Food & Nutrition Paper 66.  

Back to top

 

Won't eating sugar make me fat?

Many people still mistakenly believe that sugar is fattening. Sugar is a carbohydrate. Eating plenty of carbohydrates and taking part in regular physical activity is the healthiest way to maintain a desirable body weight.

Sugar and weight gain

The scientific evidence does not support the commonly held belief that eating too much sugar is a cause of weight gain. In fact, it is high fat diets that are linked to obesity, not high carbohydrate (or high sugar) diets.

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.

The sugar-fat seesaw

wellbeing

High sugar consumers tend to be low fat consumers and low fat consumers tend to be slimmer. Conversely, low sugar consumers tend to eat more fat and are therefore more likely to be overweight. This observation has been described as the "sugar-fat seesaw".

So if you want to stay slim, 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 will 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. The difference between carbohydrates and protein and fat is that it is easier to eat too much if the food contains fat.

Further Reading

  • Science Centre article on obesity.
  • Astrup A. et al. 2000. The role of low-fat diets in body weight control: a meta-analysis of ad libitum dietary intervention studies. International Journal of Obesity. 24(12), pp1545-52.
  • Food and Agriculture Organisation of the United Nations & World Health Organisation. 1998. Carbohydrates in Human Nutrition. Report of a Joint FAO/WHO Expert Consultation. FAO Food & Nutrition Paper 66.
  • Gibney M.J. 1995. Epidemiology of obesity in relation to nutrient intake. International Journal of Obesity, 19(Suppl 5), ppS1-S3.
  • Saris et al. 2000. Randomised controlled trial of changes in dietary carbohydrate/fat ratio and simple vs. complex carbohydrates on bodyweight and blood lipids: the CARMEN study. International Journal of Obesity, 24, pp1310-1318.

Back to top

 

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.

drink cans

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 consumer 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.

Low-calories drinks and slimming

People who are overweight often choose low-calorie drinks in an attempt to lose weight but, here again, the evidence that this single strategy works is inconclusive. Successful slimming requires a change in lifestyle. Choosing particular low-calorie foods or drinks may be useful as part of this general change but is unlikely to be successful on its own.

Further Reading

  • Anderson G.H. 2006. Sugars-containing beverages and post-prandial satiety and food intake. International Journal of Obesity, 30, ppS52-59.
  • Gibson S. and Neate D. 2007. Sugar intake, soft drink consumption and body weight among British children: further analysis of National Diet and Nutrition Survey data with adjustment for under-reporting and physical activity. International Journal of Food Sciences and Nutrition, 58(6), pp445-460.
  • Gibson S.A. 2000. Associations between energy density and macronutrient composition in the diets of pre-school children: sugars vs. starch. International Journal of Obesity, 24, pp633-638.
  • Pereira M.A. 2006. The possible role of sugar-sweetened beverages in obesity etiology: a review of the evidence International Journal of Obesity, 30, ppS28–S36.
  • Stubbs J., Ferres S., Hargan G. 2000. Energy density of foods: Effects on energy intake. Critical Reviews of Food Science and Nutrition, 40, pp481-515.
  • World Health Organization and Food and Agriculture Organization. 2003. Diet, nutrition and the prevention of chronic diseases. Report of a Joint FAO/WHO Expert Consultation. WHO Technical Report Series 916. WHO Geneva, Switzerland.

Back to top

 

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.

Most people get spots at some stage in their life, especially during adolescence, and in some cases their spots may persist. Sufferers from acne should wash their face twice a day with a mild soap and pat dry. Try to avoid wearing makeup, or if you must wear makeup chose varieties that are 'noncomedogenic' as these are designed to prevent pores from becoming blocked. Non-prescription treatments are available and may help to clear acne and prevent future 'outbreaks'. In more serious cases, however, it may require medical treatment.

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.

Back to top

 

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, buns 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, buns, 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

  • Gibney M.J. 1995. Epidemiology of obesity in relation to nutrient intake. International Journal of Obesity, 19(Suppl 5), ppS1-S3.
  • Gibson S.A. 1996. Are high-fat, high sugar foods and diets conducive to obesity? International Journal of Food Sciences and Nutrition, 47, pp405-415.
  • Gibson S.A. 2000. Associations between energy density and macronutrient composition in the diets of pre-school children: sugars vs. starch. International Journal of Obesity, 24, pp633-638.
  • Gibson S., Lambert J. & Neate D. 2004. Associations between weight status, physical activity and consumption of biscuits, cakes and confectionery among young people in Britain. Nutrition Bulletin, (Nov):29, pp301-309.

Back to top

 

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

sweets

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 the diet for people with diabetes.

Further Reading

  • Franz M.J. et al. 2002. Evidence-based nutrition principles and recommendations for the treatment and prevention of diabetes and related complications. Diabetes Care, 25(1), pp148-199.
  • Simpson E.J., Holdsworth M., Macdonald I.A. 2006.  Ambulatory blood glucose measurement, dietary composition and physical activity levels in otherwise healthy women reporting symptoms that they attribute to hypoglycaemia. British Journal of Nutrition, 95, pp1127-1133.
  • Wolever T.M.S. 2006. Physiological mechanisms and observed health impacts related to the glycaemic index: some observations. International Journal of Obesity, 30, ppS72-S78.

Back to top

 

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.

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. Dentists also recommend having a dental check-up every six months so that any tooth decay can be spotted early on. Your dentist can also advise you whether you are cleaning your teeth properly.

Rates of tooth decay have fallen dramatically over the past 20 years. Many people now reach adulthood without any fillings at all. Provided you brush your teeth properly twice a day and don't eat carbohydrate-containing foods too often, you can continue to enjoy sweet things without harming your teeth.

Further Reading

  • Science Centre article on dental health.
  • Anderson CA, Curzon MEJ, Van Loveren C, Tatsi C, Duggal MS. Sucrose and dental caries: a review of the evidence. Obesity Reviews (2009) 10 Suppl.1 pp41-54.
  • Cottrell R.C. 2005. Dental Disease in Encyclopaedia of Human Nutrition, 2nd Edition; p527-534. Eds Caballero, Allen & Prentice. Elsevier Academic Press, Oxford.
  • Duggal M.S., Toumba K.F., Amaechi B.T., Kowash M.B. and Higham S.M. 2001. Enamel demineralisation in situ with various frequencies of carbohydrate consumption with and without fluoride toothpaste. Journal of Dental Research, 80, pp1721-1724.
  • Food and Agriculture Organisation of the United Nations & World Health Organisation. 1998. Carbohydrates in Human Nutrition. Report of a Joint FAO/WHO Expert Consultation. FAO Food & Nutrition Paper 66.   
  • Food and Nutrition Board, Institute of Medicine, National Academy of Sciences. 2002. Dietary reference intakes for energy, carbohydrates, fiber, fat, protein and amino acids. National Academic Press. USA.  
  • König K.G. 2000. Diet and oral health. International Dental Journal, 50, pp162-74.
  • van Loveren C. and Duggal M.S. 2001. The role of diet in caries prevention. International Dental Journal, 51, pp399-406.

Back to top

  • HEALTH PROFESSIONALS

    Visit this section to find out more about our resources – Nutrition in Practice and Patient Leaflets.

  • FOR SCHOOLS

    Discover the history and geography of sugar, together with how it is produced.

  • SCIENCE CENTRE

    Visit the Science Centre to read the latest research on carbohydrate nutrition.