• Introduction to diabetes
• Treatment & your health
• Living with diabetes
• What care to expect
• Year of care
• Complications
• Food and recipes
• Food and diabetes
• Recipes
• Shopping
• Celebrations and eating out
• Fasting and diabetes
• The dangers of fasting
• Your diet and treatment
• Other factors to consider
• Alcohol and diabetes
• Sugar and sweeteners
• Educational events
• Your stories
• My life - for young people with diabetes

Your diet and treatment

Fasting can have an impact on your diet and treatment of diabetes.  

Changes to diet

The body is used to having regular amounts of food throughout the day. When fasting people often have larger meals either side of the fast. The type of food eaten should
be considered. It is important not to forget the principles of healthy eating which should be applied to your regular daily intake. This does not mean you cannot enjoy special foods prepared at this time, rather you should consider the quantities eaten and choose healthy options where applicable, eg take sugar-free drinks and eat plenty of fruit and vegetables. Some people with diabetes will also make sure they take less salt prior to fasting in order to reduce the effects of dehydration.

People whose diabetes is controlled by diet and physical activity alone should be able to fast but this should be discussed with your healthcare team.

Changes to treatment

The body will have difficulties maintaining adequate blood glucose levels during the period of fasting, so adjustments need to be made to any prescribed medication.
If you are taking insulin it is important that your control is good before you consider fasting. Your healthcare team may advise against fasting if you have poor control or if there is evidence of complications due to diabetes. You will require less insulin before the start of the fast, and the type of insulin may also need changing from your usual type. Pre-mixed insulin is not recommended for people who are intending to fast. Due to the dangers of omitting insulin for 25 hours, you may be advised not to fast for this length of time. Your healthcare team should advise on what is best for you.
If you take tablets to control your blood glucose it may be possible to alter the time and/or dose during the fast. This will depend on the type of medication you are taking. Your doctor might suggest changing to an alternative tablet in order to prevent large variations in blood glucose levels whilst fasting. It is not recommended that tablets be omitted for the full 25 hours due to the danger of raised blood glucose levels. You need to discuss this with your healthcare team.