Understanding Sugar: The Basics of Glucose and Energy
Glucose (sugar) plays a vital role in fueling your body — especially your brain and muscles. But the problem lies in long-term overconsumption, which can lead to health issues like weight gain and type 2 diabetes. In this post, we’ll break down what sugar actually is, how your body processes it, and how you can build a healthier relationship with it through better understanding and smarter choices.
The primary sugar your body uses for energy is glucose. When glucose enters your bloodstream after eating, the hormone insulin is released to help transport glucose into your cells, where it is used for energy or stored for later. Insulin acts like a key, unlocking your cells to allow glucose entry. Efficient insulin function is crucial to maintaining healthy blood sugar levels and overall metabolic health.
Types of Sugar and How They Work in the Body
Glucose
Glucose is the body’s primary energy source and is absorbed quickly into the bloodstream after digestion. The rise in blood glucose signals the pancreas to release insulin, which helps move glucose from the blood into muscle, liver, and fat cells. Muscle and liver cells store glucose as glycogen to be used later during activity or fasting. If energy needs are met and glycogen stores are full, excess glucose can be converted to fat.
Fructose
Fructose occurs naturally in fruit and honey but is also found in many processed foods as high-fructose corn syrup. It is metabolised exclusively in the liver and does not directly raise blood sugar. However, excess fructose — especially from processed sources — can contribute to fat storage, insulin resistance, and fatty liver due to the liver’s limited processing capacity. Moderation is important.
Sucrose
Common table sugar, made up of 50% glucose and 50% fructose. It is broken down into these two sugars in the digestive system before absorption. Found in most sweetened foods and beverages.
Lactose
A sugar found in milk and dairy products, composed of glucose and galactose.
Maltose
Made of two glucose molecules, found in malted grains, cereals, and beer.
How Sugar Is Used and Stored
After consumption, glucose enters the bloodstream and can be:
Used immediately for energy, especially by the brain and muscles
Stored as glycogen in the liver and muscles for later use, especially during exercise or fasting
Converted to fat if glycogen stores are full and energy is not immediately needed
Fructose bypasses blood sugar regulation and heads straight to the liver. If your energy demands are low and glycogen stores are full, fructose is more readily converted to fat than glucose.
Why Muscle Mass Matters
Muscle tissue is critical for blood sugar regulation. It acts like a sponge, absorbing glucose from the bloodstream to use as energy or store as glycogen. The more muscle mass you have, the greater your capacity to store glucose, resulting in:
Lower insulin response
Improved glucose tolerance
Reduced risk of insulin resistance
Physical activity enhances this effect by increasing insulin sensitivity, meaning your body requires less insulin to manage blood sugar. Over time, this leads to better metabolic health and protection against conditions like type 2 diabetes and cardiovascular disease.
Where Are These Sugars Found?
| Sugar Type | Common Food Sources
| Glucose | Fruits, starchy vegetables, grains, processed foods
| Fructose | Fruit, honey, fruit juice, processed foods (high-fructose corn syrup)
| Sucrose | Table sugar, baked goods, soft drinks, sweet cereals
| Lactose | Milk, yoghurt, dairy products
| Maltose | Cereal, malted drinks, beer
How Much Sugar Is Too Much?
When it comes to sugar, moderation is key — especially with added sugars found in processed foods and drinks.
According to the Australian Dietary Guidelines, the recommended upper limit for added sugar intake is:
Up to 50 grams per day (about 12 teaspoons), representing 10% of daily energy intake (based on a standard 8,700 kJ or ~2,000 kcal diet).
Ideally, aim for no more than 25 grams per day (about 6 teaspoons) for additional health benefits — around 5% of total energy intake.
To put this into perspective:
| Food/Drink Item | Approximate Sugar Content
| 1 can of soft drink (375 ml) | 35–40 g (9–10 tsp)
| 1 standard chocolate bar (50 g) | 25–30 g (6–8 tsp)
| 1 tbsp honey or maple syrup | 15–20 g (4–5 tsp)
| 1 flavoured yoghurt (150 g) | 15–20 g (4–5 tsp)
It’s surprisingly easy to exceed these limits, especially if your day includes multiple packaged snacks, sweetened drinks, or desserts.
In Summary
Sugar is an essential part of how your body produces energy, but the type, amount you consume and what you pair it with (to be discussed!) matters. Focus on sensible amounts of whole-food sources of natural sugar (like fruit and dairy) over added sugar found in processed foods and desserts, build and maintain muscle to improve how your body uses glucose, and limit added sugars where possible for better energy, mood, and long-term health.
