Understanding how carbohydrates work, why your body needs them, and which carbs diabetics should limit or avoid can help you manage diabetes more effectively while still maintaining energy, nutrition, and overall health.

What Are Carbohydrates and Why Are They Important?

Carbohydrates are one of the body’s three main macronutrients, alongside protein and fat. Their primary role is to provide glucose, which is the body’s preferred source of energy.

Glucose fuels:

• The brain (which relies almost entirely on glucose)

• Muscles during movement and exercise

• Red blood cells

• Many essential metabolic processes

When you eat carbohydrates, your digestive system breaks them down into glucose, which enters the bloodstream. Insulin then helps move glucose into cells where it’s used for energy or stored for later use.

Without carbohydrates, the body must rely more heavily on fat and protein for fuel. While this can work short term, long-term carbohydrate restriction can affect energy levels, gut health, mood, and nutritional balance, especially if not done carefully.

Why Carbohydrates Are Challenging for People With Diabetes

In diabetes, the body either doesn’t produce enough insulin (type 1) or doesn’t use insulin effectively (type 2). This means glucose can build up in the bloodstream instead of being used for energy.

The problem isn’t carbohydrates themselves — it’s how quickly certain carbohydrates raise blood sugar.

Fast-digesting carbs cause rapid glucose spikes, while slower-digesting carbs provide steady energy and better blood sugar control.

The Different Types of Carbohydrates

Not all carbohydrates are the same. They fall into three main categories:

1. Simple Carbohydrates

These are sugars that digest quickly and raise blood sugar rapidly.

Examples:

• Table sugar

• Honey, syrups

• Fruit juice

• Soft drinks

• Lollies and desserts

2. Complex Carbohydrates

These contain longer chains of glucose and usually digest more slowly — especially when paired with fibre.

Examples:

• Whole grains

• Legumes

• Vegetables

• Oats, barley, brown rice

3. Fibre

Fibre is a type of carbohydrate that is not digested into glucose. It slows digestion, improves gut health, and helps stabilise blood sugar.

Examples:

• Vegetables

• Berries

• Beans and lentils

• Seeds and nuts

For diabetics, fibre is especially important.

Carbohydrates Diabetics Should Avoid or Limit

People with diabetes don’t need to eliminate carbohydrates — but they should avoid carbs that raise blood sugar quickly and offer little nutritional value.

1. Refined and Processed Carbohydrates

These have had fibre removed, causing rapid glucose spikes.

Avoid or limit:

• White bread and white rolls

• White rice

• Regular pasta

• Pastries and cakes

• Crackers made with refined flour

2. Sugary Drinks and Fruit Juice

Liquid carbohydrates are absorbed extremely quickly.

Avoid:

• Soft drinks

• Sports and energy drinks

• Fruit juice (even “100% juice”)

• Sweetened iced teas

These drinks can raise blood sugar faster than almost any solid food.

3. Highly Processed Snack Foods

Often high in refined carbs, sugar, and unhealthy fats.

Avoid:

• Chips and crisps

• Sweet biscuits

• Muesli bars with added sugars

• Processed breakfast cereals

4. High-Sugar Fruits and Dried Fruit (including fruit juices)

While whole fruit can be part of a diabetic diet, some fruits are higher in sugar.

Limit:

• Bananas (especially ripe)

• Grapes

• Mangoes

• Pineapple

• Dates, sultanas, raisins

Portion size is critical.

Better Carbohydrate Choices for Diabetics

Instead of eliminating carbs, diabetics should focus on low-GI, high-fibre carbohydrates that digest slowly.

Better options include:

• Non-starchy vegetables (broccoli, spinach, zucchini, cauliflower)

• Legumes (lentils, chickpeas, beans)

• Whole grains (oats, barley, quinoa)

• Low-GI fruits (berries, apples, pears)

• Seeds and nuts

• Wholegrain or sourdough bread (small portions)

Pairing carbohydrates with protein and healthy fats further slows digestion and improves blood sugar control.

How Much Carbohydrate Should a Diabetic Eat?

There is no single perfect number. Carbohydrate needs depend on:

• Medication or insulin use

• Activity level

• Body weight

• Blood sugar response

Many experts recommend:

• 30–60 grams of carbs per meal

• 10–20 grams per snack

Monitoring blood glucose helps identify what works best for you.

The Bottom Line

Carbohydrates are not the enemy — they are an essential source of energy and nutrition. For people with diabetes, the key is choosing the right carbohydrates, controlling portion sizes, and avoiding highly processed, sugary, fast-digesting carbs that cause blood sugar spikes.

By focusing on whole, fibre-rich, low-GI carbohydrates and pairing them with protein and healthy fats, diabetics can enjoy balanced meals, stable energy levels, and better long-term health.

Carbs matter — it’s just about making them work for your body, not against it.