The Story of Sugar

The Story of Sugar

The Story of Sugar

The Story of Sugar

The Story of Sugar

It is important to have a healthy relationship with sugar, and to achieve this you need to understand what it’s all about! Understanding the benefits and the disadvantages of sugar in your diet will allow you to make an educated decision of how and when to use it.

In light of the current obesity epidemic, sugar has gained a bad reputation. However, like any nutrient, excessive intakes are not going to be good for you. It’s really all about balance and learning what this really means. Sugar occurs naturally in nearly all foods, but there is also additional sugar added to many foods. Learning about sugar, where it comes from, why we use it and the implications of using too much sugar, will empower us to make healthier dietary choices and let us enjoy sugar responsibly. Through this document we aim to highlight the key uses of sugar in food production and its role in the diet. There’s nothing wrong with adding a little sweetness to your life!

What is sugar?

Sugar is the naturally-occurring nutrient that makes food taste sweet. It is a simple carbohydrate that is metabolised by the body, primarily to produce energy. “Energy metabolism refers to the ways in which the body obtains and spends energy from food.” (Sugar can also be stored in the body and then used for energy when required. Sugars are grouped into monosaccharides, which include glucose (found in nearly all carbohydrate containing food), fructose (mainly found in fruit), and disaccharides, such as sucrose (common table sugar) and lactose (milk sugars).

Your dietary sugars supply four calories of energy for each gram of carbohydrate you consume. To put this in perspective, protein also provides four calories per one gram, while alcohol provides seven calories per gram and fat provides nine calories per gram.

Where does sugar come from?

Common table sugar comes from either sugar cane or sugar beet. Both sugar cane and beet are found in the tropical and semi-tropical climates of the world. In both cases, the juice is extracted from the sugar beet or cane and impurities are removed. It is then crystallised into white sugar, which is 99.95% sucrose. Sugar is identical whether it comes from beet or cane.

These crystals can then be further processed to form various different types of sugar. These include:

  • Granulated: This is your common table sugar. It consists of larger sugar crystals than caster and icing sugar.
  • Caster: The granulated sugar crystals are ground down further to produce caster sugar. Small grains ensure smooth blending to give even textures in cakes and other baked foods.
  • Icing: This is granulated sugar ground into a fine powder. It dissolves very quickly because of its very fine texture. It is usually used to decorate baked goods.

What is the difference between brown and white sugar?

Brown sugar results from the presence of molasses. When sugar has been extracted from the juice of the beet or cane plant, a strong tasting black syrup (known as molasses) remains. The molasses is completely removed to produce white sugar. The more molasses that there is in the brown sugar, the darker the colour, the stickier the texture and stronger the flavour. For example, soft dark brown sugar contains more molasses than soft light brown sugar, and therefore has a darker colour.

Is the sugar in fruit the same as sugar added to baked goods?

Sugar can be categorised into intrinsic sugars or extrinsic sugars (free sugars). Intrinsic sugars refer to sugars that exist within the cell walls of a plant. These sugars are encapsulated by the fruit or vegetable cell wall and tend to be digested more slowly and take longer to enter the blood stream than free sugars.

Extrinsic sugars, or free sugars, have been released from the cells of the plant such as when oranges are juiced and the cell walls are broken. The World Health Organisation, defines “free sugars” as all monosaccha­rides and disaccharides added to foods by the manufacturer, cook or consumer, plus the sugars that are naturally present in honey, syrups and fruit juices.(WHO) All sugars are metabolised in the same way once digested but the rate of digestion to when glucose enters the blood stream depends on a number of factors including the form in which it has entered the body.  

Why do we add sugar to our food?

Sugar has a number of important uses in food production. It plays a key role in enhancing the flavour, acting as a preservative or as a bulking agent in a variety of foods.

  • One of the main uses of sugar in baking and cooking is to enhance flavour. Sugar offers a lovely sweet taste that can be used to counter acidic and bitter tastes.
  • Sugar acts as a preservative. The high sugar content in jams, marmalades and other syrupy fruit desserts prevents microbial growth and spoilage, and makes these foods last longer.
  • Sugars provide volume to cakes and biscuits. Also, the combination of sugar with a gelling agent such as pectin is responsible for the jelly texture of jams.
  • Another function of sugar in baking is to add colour. The golden-brown crust of baked products, such as biscuits and toasted bread, is due to a reaction that occurs under heat between sugars and proteins.


Sugar and Health

Does eating sugar lead to weight gain?

“Obesity results from an imbalance between energy intake and energy expenditure.” Excessive intake of energy with little energy expenditure leads to weight gain and obesity. The key word in this sentence is excessive. Simply put, too much energy in and not enough energy out will lead to weight gain. Foods that are high in fat or added sugars and low in fibre, contribute most to increased weight gain.” It is therefore important to consider the composition of the foods that you consume and the frequency of consumption. Sugar should be eaten in moderation and enjoyed as part of a healthy balanced diet.

The daily reference intake of sugar for the average adult is 90g. This means you should not eat more than 90g of sugar a day. This includes sugars that are added to foods and occur naturally in foods. The reference intake for total carbohydrate is 260g per day and the recommended intake for fibre is 25g per day. (

Sugar and Exercise

The type of lifestyle that you lead should also be considered. If you lead a sedentary lifestyle you should consume less foods that are high in the nutrients fat, sugar and salt. However, if you have a very active lifestyle and exercise regularly, carbohydrates, including sugar are important sources of energy during exercise and are also important for recovery after exercise.  

Does sugar cause dental decay?

Sugar is a wonderfully tasty nutrient that is found in many foods, but excessive intakes for both adults and children can cause dental decay. Dental caries are caused when the resistant bacteria in the month ferment sugars to produce acid. The dental enamel dissolves in the plaque fluid and repeated exposure to periods of low pH (acidic environment) can lead to decay. It is therefore extremely important to follow proper oral hygiene practices and not to consume excessive amounts of high sugar foods. (HN)


Sugar and Diabetes

Diabetes is a condition where there is too much glucose in your blood. This happens when your body’s hormone, insulin, is not working as it should. Insulin moves glucose from your blood to your cells so your body can use it for energy.

There are three forms of diabetes. Type 1, Type 2 and Gestational Diabetes.

  1. Type 1 diabetes occurs when the pancreas fails to produce enough or no insulin at all. This results in high blood glucose levels and can have detrimental effects. This is managed with insulin injections and monitoring diet and lifestyle. The cause of type 1 diabetes remains poorly understood but genetic factors may play a role. Although this form of diabetes is the most extreme form, it is not prevented by dietary intervention. (PHN 334)
  2. On the other hand, type 2 diabetes “is a multifactorial disease having equally strong genetic and environmental components contributing to its development. Some of these factors can be modified by lifestyle changes, whereas other factors cannot.” (Public Health Nutrition (2012) (pg330)) Such environmental factors include the types of food you eat and the frequency that you eat these foods. You should limit the amount of high fat and high sugar foods and drinks in your diet and ensure that you include regular exercise.
  3. During pregnancy, women can develop gestational diabetes due to changes in hormone levels. This type of diabetes, which occurs during pregnancy usually goes away after the baby is born. If not treated, gestational diabetes can cause health problems for you and your baby. Developing gestational diabetes shows that you are also at risk of developing diabetes in later life. To prevent this, it is very important to maintain a healthy lifestyle and healthy weight throughout your lifetime. (INDI (2013) Healthy Eating With Gestational Diabetes)

What is a balanced diet?

The Department of Health have developed healthy eating guidelines for adults and children over 5 years of age. This offers a simple guide to the types and quantities of foods you should be consuming on a daily basis. The food pyramid helps to categorise foods.


As the food pyramid is wider at the bottom, this means you should consume more of these foods.

Shelf 1 (Bottom Shelf):

The very bottom shelf consists of starchy carbohydrates. These are complex sugars that are easily broken down for energy such as, pasta, bread, grains and potatoes. You should try and aim for wholegrain products where possible, as these are an important source of fibre and other important nutrients. You should choose six or more foods from this shelf, depending on how active you are.

Shelf 2:

The fruit and vegetable shelf is second from the bottom and is an important shelf with regards to micronutrients (vitamins and minerals). Fruits and vegetables are also an important source of fibre and contain the natural sugar fructose. When the fruit or vegetables are intact and we eat them as they are, they contain what we call, intrinsic sugar. These sugars are encapsulated by the fruit or vegetable cell wall and tend to be digested more slowly and take longer to enter the blood stream than free sugars. Some free sugars include sucrose added to foods, milk sugars or juice drinks made from fruits and vegetables. Dried fruit would also be included on this shelf but should be consumed in small quantities. 25-30g (1 tablespoon) of dried fruit would be considered one of your five a day.

Shelf 3:

You are recommend to have three portions of dairy each day. Dairy is an important source of calcium and other important nutrients. It also contains a natural sugar called lactose, which gives milk and cheese their slightly sweet taste. Lactose is an important sugar that is required by the body for calcium absorption. Yogurt also contains lactose but in many cases also contains added sugars. It is therefore recommended to only consume one yogurt per day.

Shelf 4:

The average person is only recommended to have two portions of protein each day. This can vary depending on how much and the type of exercise you do each day. This shelf includes foods such as meat, eggs, fish, beans, lentils and nuts. There is very little sugar found in these types of foods.

Shelves 5 & 6 (Top Shelves):

As you move up the food pyramid, the shelves get smaller and this means you should consume less of the foods higher up the food pyramid. Foods that are high in fat, sugar and salt are at the top of the food pyramid and therefore should be enjoyed in small amounts. Fats and oils are required by the body but only in very small amounts.

High fat, sugar and salty processed foods are at the very top of the food pyramid. Honey would also slot into this shelf on the food pyramid. This means that you could survive without these foods but we all enjoy a little treat, so it’s fine to enjoy them every now and again.

To find out more about healthy eating you can access the Department of Health’s guidelines here 

(Reference: Department of Health/ Health Service Executive (2012) The Food Pyramid)

How to read food labels:

A little bit of added sugar each day does no harm. It’s when it’s consumed in excessive amounts that health issues can occur. Sweetened foods should be kept as a treat rather than a regular feature of your diet.

Understanding how to read food labels is a great first step in achieving a balanced diet.

If you are concerned about the sugar in a food product or if it contains naturally occurring or added sugar, the first place to look is the ingredients list. If the sugar is naturally occurring in a food, sugar won’t appear in the ingredients list. If there is added sugar you can gauge how much is present by how high up it is in the ingredients list. For example, if it is one of the first ingredients in the list, the product will be high in sugar and if it is lower down in the list, it will have a lower sugar content. Other names for sugar to look out for in the ingredients list include sucrose, glucose, fructose, maltose, hydrolysed starch, invert sugar, corn syrup, molasses, raw sugar, dextrose, mannitol, golden syrup, malt extract, brown sugar and honey.

The next step is to look at the nutrition information. The amount of sugar present in the product will be listed per 100g, under carbohydrates. It may also be provided per portion. This figure includes both naturally occurring sugars and added sugars. If a food has 5g of sugar or less per 100g it is considered a low sugar food (2.5g for liquids). If it has 15g of sugar or more per 100g it is considered a high sugar food. (FSAI (2014) Information on nutrition and health claims)


Gibney MJ. et al (2012) Public Health Nutrition. Second Edition. Blackwell Publishing.

Lanham-New S. et al (2011) Nutrition and Metabolism. Second Edition. Wiley-Blackwell.

Gibney MJ. et al (2009) Introduction to Human Nutrition. Second Edition. Wiley-Blackwell.

INDI (2013) Healthy Eating with Gestational Diabetes:

Department of Health/ Health Service Executive (2012) The Food Pyramid..