The main types of sugar are sucrose, lactose, and fructose. Common table sugar is typically sucrose, which is extracted from cane or beets.
What is in sugar?
Added sugars can cause obesity-related health problems - always check the nutritional information to moderate your intake.
Sucrose, or table sugar, is made from glucose and fructose. Glucose is found in many different types of carbohydrates like grains, fruit, and vegetables. Fruit, vegetables, and honey contain fructose, while milk has lactose.
These base units of the common sugars are known as saccharides. The smallest are monosaccharides, which consist of a single unit. These include:
Glucose is often referred to as blood sugar, as it is the type of sugar found circulating in our blood. Galactose is contained in milk. Both fructose and sucrose can be found in fruit.
The other primary category of sugars is disaccharides. These are made of a combination of two or more monosaccharides, for example:
- sucrose, also known as table sugar = glucose + fructose
- lactose, also known as milk sugar = glucose + galactose
- maltose = glucose + glucose
When people talk about "sugar," they often mean table sugar, or sucrose, whereas "sugars" refers to the whole group of saccharides.
The most commonly found added sugar is sucrose, or table sugar.
White sugar consists of 99.95 percent sucrose, and its varying types are often due to crystal size.
There are different types of specialty white sugars:
- Superfine or bar sugar: the crystals are very small and dissolve easily.
- Confectioner's or powdered sugar: extremely fine, dust-like crystals.
- Sugar cubes: lumps of sugar crystals stuck together with sugar syrup.
- Coarse sugar: the crystals are especially large and resistant to breakdown at cooking temperature.
Nutritional value of white sugar per 100 grams (g), or 3.5 ounces:
- Energy 1,619 kilojoules (387 kilocalories)
- Carbohydrates 99.98 g
- Sugars 99.91 g
- Dietary fiber 0 g
- Fat 0 g
- Protein 0 g
- Water 0.03 g
- Riboflavin (Vit. B2) 0.019 milligrams (mg)
- Calcium 1 mg
- Iron 0.01 mg
- Potassium 2 mg (0 percent)
Unlike white sugar, brown sugar contains molasses. Molasses is the raw juice from the extraction process which draws the sugar from the cane or beet. As a result of the naturally occurring minerals from the molasses, it contains slightly more nutritional value than white sugar.
Among the many types and styles of brown sugar, the main two are:
- Sticky brown sugar contains a heavier concentration of molasses that make it denser and sticker.
- Free-flowing brown sugar consists of finely granulated sugars that do not stick together and therefore "flow" like white sugar.
Nutritional value of brown sugar per 100g (3.5oz):
- Energy - 1,576 kJ (377 kcal)
- Carbohydrates - 97.33 g
- Sugars - 96.21 g
- Dietary fiber - 0 g
- Fat - 0 g
- Protein - 0 g
- Water - 1.77 g
- Thiamine (Vit. B1) - 0.008 mg
- Riboflavin (Vit. B2) - 0.007 mg
- Niacin (Vit. B3) - 0.082 mg
- Vitamin B6 - 0.026 mg
- Folate (Vit. B9) - 1 microgram (μg)
- Calcium - 85 mg
- Iron - 1.91 mg
- Magnesium - 29 mg
- Phosphorus - 22 mg
- Potassium - 346 mg
- Sodium - 39 mg
- Zinc - 0.18 mg
Liquid sugars and syrups: some made of pure sucrose are commonly used in food processing to add flavor and color. Golden syrup is made by breaking down the disaccharide sucrose to its constituent sugars - glucose and fructose - a process called inversion. Inversion helps prevent crystallization during storage. Treacle is made from molasses.
Sugars in the diet
Brown sugar is an alternative to white sugar and contains natural molasses.
Dietary sugar, or the sugar that we eat, can be naturally occurring, such as fructose in fruit or lactose in milk.
Added sugars are those we put on our food or in our drinks before eating, as well as sugars and syrups that have been added to foods in processing and preparation.
Foods with added sugars include sodas, candy, cakes, cookies, pies, fruit drinks, desserts, dairy products, breakfast cereals, and processed foods.
It is recommended to look carefully for added sugars in the ingredients listed on the packaging. These may be included under several names, many ending with the letters -ose, such as:
- high fructose corn syrup
- cane sugar
- corn sweetener
- raw sugar
- syrup, honey
- fruit juice concentrates
Added sugars should make up no more than 5 percent of our daily energy intake.
Added sugar supplies no extra nutritional value to a meal, and our bodies do not need it to function. It serves only to add calories to our daily energy intake, and unused calories are turned into fat and extra weight.
People with diabetes do not need to cut sugar from their diets completely, but some careful moderation is required.
Sugar also has a corrosive effect on the teeth and can cause tooth decay and gum disease.
Diabetics can consume sugar, but people with diabetes are recommended to consume no more than 25 g daily. This is half the recommended amount for those without diabetes.
As exercise uses the excess calories generated by added sugar, its intake is less harmful, though still not advisable, as part of a balanced diet and active lifestyle.
An overview of the sugar content of popular foods can be found in the article, How much sugar is in your food?