Fasting is the practice of restricting food or drink intake for a period of time.

Fasting and diabetes

The body does not store carbohydrates for long-term energy. During fasting, once glucose is used up, the body begins burning stored fat for energy. This process can help reduce excess fat that contributes to insulin resistance—the ‘gum in the lock’ that makes insulin less effective.

Risks of hunger and overeating

Fasting can increase hunger, which may lead to overeating or consuming high-fat foods, negating the benefits. It is not recommended for individuals with a current or past history of disordered eating, as it may trigger relapse.

Fasting on a plant-based diet

On a low-fat, whole food, plant-based diet, the body naturally burns excess stored fat without the need for fasting. This dietary pattern also tends to be lower in calories, making weight management easier. Fasting while following such a diet can risk undereating and nutritional deficiencies, especially in people who exercise regularly.

Speak to your doctor first

Fasting can affect blood glucose levels and interact with medications, particularly insulin. Always consult a healthcare professional before starting a fasting regimen.

Note: Specific guidance may apply for people with diabetes during fasting periods such as Ramadan. For more information, click here.

Recap

You can’t out-fast a high-fat diet. Long-term improvements in diabetes health come from:

• Following a low-fat, whole food, plant-based diet
• Managing sleep and stress
• Addressing smoking and alcohol use

Evidence for fasting in type 2 diabetes is limited and mixed. Focus on proven strategies such as diet, exercise, and lifestyle management for lasting results.