How is sugar used by the body?
Sugar is a general term for a sweet carbohydrate that is used to flavour foods and drinks. Glucose and fructose are two of the most commonly encountered sugars and are utilised by our bodies in different ways.
GlucoseGlucose is found in white sugar, honey, fruits and vegetables.
Our bodies process glucose in three different ways: for using as energy, converting into triglycerides or storing as fat.
FructoseFound in fruits and honey, fructose can only be processed by the liver. A small amount of the fructose is converted into glucose for energy, but most is converted to triglycerides and stored as fat.
Furthermore fructose doesn’t stimulate the production of insulin or the hormones that control appetite (ghrelin and leptin).
For these reasons, excess fructose consumption is now widely recognised as a contributing factor in rising levels of obesity and insulin resistance.
One of the main culprits of this is thought to be high-fructose corn syrup, a popular sugar substance used in food manufacturing.
There are many other sweet substances that are chemically different from sugar. These are used widely by food and drink manufacturers to add a sweet taste with fewer calories. These sweeteners are usually many times sweeter than sugar.
Sweeteners can be derived from food sources e.g. stevia and xylitol, or are chemically produced and referred to as artificial sweeteners e.g. aspartame, sucralose and acesulfame potassium.
Artificial sweeteners are not a healthy alternative to sugar because they have been found to promote sweet cravings and have been linked with an increased risk of developing type-2 diabetes.
Sugar's impact on the body
Sugar can provide a quick energy boost and is often used by people as a pick me up. Sugar will give a quick rise in the levels of glucose in the blood stream but this is only short lived. A blood sugar drop will always follow a sugar high leading to further consumption of sugar and the continuation of energy peaks and troughs throughout the day.
Sugar that is not used up immediately is stored as fat (by the hormone insulin). Eating sugar on a regular basis is therefore a contributing factor to obesity and fatigue as well as increasing the risk of developing type 2 diabetes and cardiovascular disease.
It is also worth noting that most sugary foods lack essential nutrients such as vitamins, minerals, essential fatty acids and protein, which we all need to be in good health. This is why sugar is often referred to as an ‘empty calorie’.
Sugar is also a leading cause of tooth decay, this is because molecules called glycoproteins from the sugar coat the teeth attracting bacteria and the subsequent wearing down of tooth enamel.
Sugar in food labels
When looking for sugar levels in a food product, always check the label. Sugar content should be below 15g per 100g (and ideally lower). The traffic light system used on products in the UK will only give you the figure for total sugars.
To understand the types of sugars in the product you will need to look at the ingredients. Foods like syrup, invert syrup, cane sugar or anything ending in ‘ose’ is a sugar. You should also look out for sweeteners that could be replacing sugar.
Sugar as part of a balanced diet
Aside from providing a quick energy source, sugar does not provide the body with beneficial nutrients e.g. vitamins and minerals.
Foods that provide a longer sustained energy release are a much better way of fuelling your body for long-term health. Wholegrain carbohydrates (bread, rice and pasta) combined with lean protein (pulses, meat, fish, eggs) and plenty of fresh vegetables and fruits are all vital components of a healthy lifestyle.
Enjoying the occasional sugary snack or drink is fine e.g. enjoying birthday cake with a family or a sugary drink on an evening out. If you eat healthily 80% of the time, then there is room for you to choose the unhealthy option sometimes. Just make sure that the unhealthy options don’t become the norm.
Find out more about typical sugar consumption in our Sugar Balance Infographic.
Last updated Tuesday 20 September 2022
First published on Monday 30 November 2015