Think about the foods you most enjoy eating. Chances are they contain some form of sugars. It could be the sugars in mangoes plucked fresh from the tree, or the sugars added to your favourite dessert or ice cream to give it that wonderful taste.
As part of a healthy, balanced diet, you can enjoy sugars in moderation. This article answers questions you may have about sugars and their role in a healthy diet.
What are sugars?
Sugars are carbohydrates, an important source of energy for the body. Other carbohydrate-rich foods include fruits, root vegetables (including potatoes), rice, noodles and bread. However, before the carbohydrates in these foods can be used for energy, they must be digested and broken down into sugars.
When we talk about sugar we usually refer to table sugar or sucrose, from cane or beet. There are many other types of sugars. Some occur naturally in fruits, vegetables and milk. Sugars are also added as ingredients to many foods.
The body does not distinguish between one sugar or the next and treats them all in essentially the same way, whether they occur naturally in a food or are added. All sugars provide the same amount of calories (approximately 4 calories or 16 kilojoules per gram).
Why are sugars added to foods?
Most people enjoy the sweet taste of sugars. However, enhancing sweetness is only one of the important roles sugars play in food.
- Using sugars can improve the texture and colour of baked goods. Sugars help produce the moistness of cakes and the golden-brown colour and crispy texture of biscuits.
- Sugars are needed when baking bread to enable yeast to work.
- Sugars balance the sour taste of tomatoes in sauce, vinegar in achar and tamarind in assam gravies.
How do sugars fit into a healthy diet?
A healthy diet should include a variety of different types of foods such as: 
- Cereals and Cereal Products
- Roots and Tubers
- Fruits
- Vegetables
- Legumes (Peas and Beans)
- Meat, Poultry and Fish
- Dairy Products
Some foods contain sugars naturally (such as fruit and milk) while other foods may have sugars added (such as ice cream, cakes and biscuits). Added sugars can make nutritious foods more appealing. For example, a glass of lime juice, a bowl of soybean curd or a dessert of red bean soup, often taste better with a little added sugar.
The Food and Agriculture Organisation of the United Nations (FAO) has indicated that sugars can play a role in a healthy diet. However, if your energy needs are very low or you are overweight, you should go easy on the total calories from all sources that you consume.
How does the body use sugars?
Sugars are an important source of energy for the body. There are no caloric differences between sugars. Ultimately, the body uses all types of sugars in essentially the same way.
During digestion, all carbohydrates, including sugars and starches such as rice, noodles and bread, break down into single units of sugars which, in turn, are all converted to glucose. Glucose travels through the blood stream to body cells to provide energy or is stored for future use. Glucose is the only nutrient that the brain and red blood cells can use for energy.
Do sugars cause weight gain?
Weight gain results when a person regularly consumes more calories than he or she expends. Almost all foods contain calories. Excess energy may come from over-consumption of any food.
The energy content of food is measured in calories or kilojoules. Nutrients such as carbohydrate, protein and fat provide energy to the body. All carbohydrates, including sugars, provide 4 calories (16 kilojoules) per gram, which is the same as for protein. Fats provide 9 calories (37 kilojoules) per gram while alcohol provides 7 calories (29 kilojoules) per gram.
Lack of physical activity also plays a significant role in overweight. If you want to lose weight, nutritionists recommend eating fewer calories from all sources and increasing the amount of exercise you do.
Do sugars cause diabetes?
Researchers have not yet discovered why diabetes occurs. However, there is strong evidence that sugars do not cause it. A healthy lifestyle, including regular physical activity and maintaining a healthy weight, helps to reduce the risk of diabetes.
Treatment of diabetes includes a healthy diet, regular exercise and medication when prescribed. Recent nutritional guidelines from the Food and Agriculture Organisation of the United Nations and the World Health Organisation advise that most people with diabetes can enjoy moderate amounts of sugar each day as part of mixed meals.
Do sugars cause heart disease?
Many lifestyle and hereditary factors are involved in the development of heart disease such as obesity, a high intake of fat (especially saturated fat), a low intake of fruits and vegetables and lack of exercise. Sugars have not been identified as a risk factor for disease.
Do sugars cause hyperactivity?
Eating sugar does not cause hyperactivity. In a recent study, researchers examined the effect of eating sugar on the behaviour of children. The children were chosen for the study because their parents believed their children reacted negatively to sugar. The researchers found no differences in the behaviour of the children when they ate higher than normal amounts of sugar compared to when they ate diets low in sugar.
Research actually suggests that sugars tend to have a calming effect on both children and adults. This effect could go unnoticed due to other influences, for instance, the excitement of a birthday party or festival, which could override the calming effect.
Do sugars cause tooth decay?
Tooth decay is the result of many factors, including hereditary tendency and the make-up and flow of saliva. Sugars and other carbohydrates such as rice, noodles and bread, also play a part. Bacteria on the teeth use carbohydrates to make acids. Over time, these acids can break down the tooth enamel to form a cavity.
Frequent intakes of foods or drinks that contain carbohydrates may increase the chance of tooth decay by not allowing saliva sufficient time to neutralise the acids. However, the use of fluoride and better dental care has led to a decline in tooth decay in recent years. Experts advise brushing teeth with a fluoride toothpaste twice a day, especially last thing at night.
Getting to know sugars
All of the following are sugars:
Single sugars - these are made up of one molecule.
- Glucose
- Galactose
- Fructose (fruit sugar)
Double sugars - these are made up of two molecules
- Sucrose (white sugar) - made up of fructose and glucose
- Lactose (milk sugar) - made up of glucose and galactose
- Maltose - made up of two glucose molecules
Sugars used in foods
These sugars often appear on food ingredient lists:
- Glucose
- Fructose
- Lactose
- Maltose
- Sucrose (white sugar)
- Corn syrup
- Brown sugar
- Honey
References:
- FAO/ WHO Expert Consultation on Carbohydrates in Human Nutrition, 1997.
Reprinted with permission from the Asian Food Information Centre (AFIC). AFIC is a non-profit organisation with the aim of communicating science-based information on a broad range of nutrition and food safety issues. Based in Singapore, AFIC covers the entire Asian region except for Japan and Korea. AFIC can be reached at Tel: +65 832 7637 and Fax: +65 464 9260.
Date reviewed: 11 May 2005
