When we think of sugar we often picture granulated sugar or sugary foods and drinks such as chocolate, cakes, and cola. However, these aren’t the only forms sugar comes in and, in fact, some forms are useful for the body. 

What are the different forms of sugar? ‍

Sugar is found in different forms in food and drink. The most recognised forms of sugar are:

Glucose - the most abundant type of sugar in plants and the body’s main source of energy.

Fructose - mostly found in fruits, vegetables and honey, and needs to be converted into glucose to be used.

Sucrose - also known as “table sugar”, is formed from the combination of glucose and fructose. 

Lactose - found in milk and dairy products and is made from glucose and galactose.

Galactose - found in milk and dairy products.

Maltose - found in sprouted grains. 

How does our body use sugar?

Sugar is an important source of fuel and, in moderation, is great for providing your body with energy to function and carry out physical activities. However, it has become very common for us to consume more than our bodies need. Too much sugar can have negative health effects such as promoting cardiovascular disease (CVD), type 2 diabetes (T2D) and unwanted weight gain resulting in overweight or obesity. 

Carbohydrates are the predominant fuel source that our body uses for daily activity and function. These are ingested as simple sugars (glucose and fructose), disaccharides (e.g. lactose and sucrose) made up of two simple sugars joined together and complex carbohydrates, such as starch and glycogen, which are long chains of simple sugars. The most important carbohydrate is glucose, which is rarely found in the diet in this form and is usually obtained through the breakdown of complex carbohydrates. Glucose is then used by cells to create chemical energy (ATP) by respiration, which our bodies use for function and physical activity. 

After glucose is formed, our pancreas secretes a hormone known as insulin. Insulin acts like a key and unlocks our cells, allowing them to take up glucose from the bloodstream and either store it or use it for energy. When we consume too much sugar, our bodies are unable to produce enough insulin to move glucose from the bloodstream into our cells. This causes blood glucose levels to spike, and glucose then reacts with other proteins in your body to create harmful molecules. These molecules then trigger chronic inflammation and damage to tissues.

Natural, refined and added sugar

Natural sugars are those that are found in their natural forms such as in fruit, vegetables, and dairy products. These sugars aren’t seen to be harmful to our health in moderate amounts, and the foods that contain them can be beneficial because of the other nutrients they contain. For example, fruit and vegetables are packed with fibre and a variety of vitamins. 

Refined sugars are natural sugars that go through a process to make them easier to add to other foods. Some examples are table sugar and high fructose corn syrup. These sugars lose their nutrients during this refining process, so they have no health benefits and are also very high in calories. Although refined sugars do contribute to your energy requirements, these sugars are rapidly metabolised and cause an insulin spike. This makes them less useful for long-term energy needs and can leave you feeling hungry again shortly after consumption. 

Added sugars are those that are added to foods. Around 75% of all foods and beverages contain added sugar in some form. These can be from natural sources like fruit juices or honey, or from refined sugars. You will often see ‘no added sugar’ on food packing, which refers to any of these sugars that can be added during the production of food. Consumption of these sugars has been associated with various negative health effects, including fatty liver, insulin resistance, CVD, and T2D. To avoid these health conditions, we therefore need to be aware of the amount of added sugar we are consuming. 

The NHS recommends having no more than 30 g of added sugar per day. To put that into perspective, there is 35 g of added sugar in just one can of cola! So if you were to have two cans in a day you would have consumed double the recommended amount. When choosing foods to eat, be aware that low-fat foods, while low in fat, can often be high in sugar as this is frequently added to help improve the taste. For example, low-fat yoghurt can contain up to 30 g of sugar - your daily recommended serving of added sugar in just one portion.

Recommendations

The various forms of sugar all affect your metabolism differently, so you may need to consider this when deciding what to eat. Fructose does not reduce levels of ghrelin, the hunger hormone. Therefore, foods high in fructose, such as high-fructose corn syrup (HFCS), will not fill you up. However, natural forms of fructose found in fruit and vegetables have other nutrients, such as fibre, that contribute to your satiety levels, helping you feel fuller for longer.

Consuming high amounts of fructose can lead to increased body fat levels and poorer metabolic health. Checking the ingredients in foods and drinks can help you minimise your intake of products containing HFCS and reduce your added sugar intake.

All types of sugar are suitable to be eaten in moderation, however, you should pay attention to how much of each type you are consuming. If you want to decrease your intake of added sugars, making small changes to your diet is a good approach, you don’t need to completely cut out sugar. One small change, for example, is to have one fewer biscuit than you usually would. Over time, this can have a beneficial effect on your sugar intake and health.

References

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