Diabetes and fasting

What is fasting?

Fasting is the practice of avoiding food, drink or both for a specific period of time.

People may fast for different reasons, including:

• Religious practices
• Cultural traditions
• Weight management
• General health and lifestyle goals

There are different types of fasting, including:

• Intermittent fasting
• Time-restricted eating
• Religious fasting, such as Ramadan
• Medically supervised fasting

Fasting affects how the body uses glucose and stored energy, which can influence blood glucose management in people living with diabetes.

How fasting affects the body with diabetes

Fasting works by mobilising glucose and fat for energy. In the first fasting stage, the body mobilises all the glucose for energy. When there is no more glucose for energy, alpha cells in the pancreas produce glucagon and release it in response to a drop in glucose. Glucagon, a hormone produced by the pancreas to regulate blood glucose levels, helps to break down fat, particularly in the pancreas, liver, and visceral areas, creating ketones for energy. The hormone further elevates the benefits of fasting by preventing glucose levels from dropping too low.

During fasting, the body changes how it produces and uses energy. When glucose from food is not available, the body begins using stored glucose and fat for energy. Hormones such as glucagon help regulate blood glucose levels and support energy production during fasting periods.

Potential benefits of fasting

Research suggests that certain fasting approaches may support metabolic health and diabetes management and risk reduction in some people.

Potential benefits may include:

• Improved insulin sensitivity
• Lower blood glucose levels
• Weight management support
• Reduced blood pressure

Some studies also suggest that intermittent fasting or intermittent calorie restriction may support type 2 diabetes remission in certain people, particularly when combined with a structured nutrition plan with medical support.

Is fasting safe for people with diabetes?

Fasting is not recommended for everyone. Due to the metabolic nature of the condition, people with diabetes are at particular risk of complications from marked changes in food and liquid intake.

Fasting with diabetes can lead to complications that include:

• Low blood glucose (hypoglycaemia)
• High blood glucose (hyperglycaemia)
• Dehydration
• Diabetic ketoacidosis (DKA), in people with type 1 diabetes

People at higher risk during fasting include:

• People with type 1 diabetes
• People with diabetes using insulin
• People with frequent hypoglycaemia
• Pregnant women with diabetes
• People with diabetes complications
• Older adults with complex health conditions

Before starting a fast, people with diabetes should consult a healthcare professional to:

• Learn about any associated risks and complications
• Create a fasting management plan.
• Adjust medication when needed
• Monitor blood glucose levels
• Know when to stop fasting

Personalised support can help reduce the risk of complications and improve safety during fasting periods.

Managing diabetes safely during Ramadan

Safe fasting during Ramadan requires preparation and ongoing monitoring.
Important considerations include:
● Monitoring blood glucose levels regularly
● Adjusting insulin or medication timing
● Staying hydrated during non-fasting hours
● Eating balanced meals at Suhoor and Iftar
● Recognising warning signs of complications
● Knowing when to break the fast

Intermittent fasting and type 2 diabetes

Intermittent fasting is increasingly recognised by the medical community as a possible dietary approach for some people with type 2 diabetes, particularly for weight loss and blood glucose management. However, it is not suitable for everyone and should be done with medical guidance, especially for people taking insulin or other glucose-lowering medications.

Some intermittent fasting approaches include:

• Time-restricted eating
• Alternate-day fasting
• Reduced-calorie fasting schedules

Research suggests intermittent fasting may help:

• Improve insulin sensitivity
• Support weight management
• Reduce insulin resistance