If you have type 1 diabetes and want to lose weight, it is important to do it safely.

Weight loss can support your overall health if you are above a healthy weight, but changes to your food, exercise routine, and body weight can all affect your blood glucose levels and how much insulin you need.

Before making major changes to your diet, exercise routine, or insulin doses, speak to your GP. They can help you lose weight in a way that reduces the risk of hypos, high blood glucose, or ketones.

Type 1 diabetes is a lifelong condition where your body cannot produce enough insulin. Insulin is the hormone that helps move glucose from your blood into your cells, where it can be used for energy.

If you have type 1 diabetes, you need insulin treatment to manage your blood glucose levels. This might be through injections or an insulin pump.

You will also need to monitor your glucose every day. This may involve finger-prick testing, a continuous glucose monitor, or flash glucose monitoring, depending on your treatment plan.

Type 1 diabetes cannot be reversed by losing weight. This is different from type 2 diabetes, where weight loss may help some people improve their blood glucose levels or go into remission.

However, if you are above a healthy weight, losing weight safely may still benefit your health. It may support your heart health, improve energy, reduce pressure on your joints, and lower your risk of diabetes-related complications.

For some people, losing weight may also reduce the amount of insulin they need. However, you should never change your insulin dose without advice from your doctor or pharmacist.

The safest approach is usually a steady one. Avoid crash diets, skipping meals, or suddenly cutting carbohydrates without support. These changes can make your blood glucose harder to manage and may increase the risk of hypos or ketones.

Instead, focus on small changes you can keep up. This could mean reviewing portion sizes, cutting down on sugary drinks and alcohol, choosing more filling meals, and becoming more active. Try to include protein, fibre, and vegetables with meals where possible. These can help you feel fuller for longer and support a balanced diet.

If you count carbohydrates, keep doing this carefully. If your carbohydrate intake changes, your insulin doses may need reviewing.

Exercise can help with weight loss and general health. It can also improve how your body uses insulin. However, exercise can affect blood glucose levels in different ways. Some activity may lower your blood glucose during or after exercise, while high-intensity exercise can sometimes raise it for a short time.

If you are exercising to lose weight, check your blood glucose before, during, and after exercise, especially when trying something new. Carry fast-acting carbohydrate with you in case of a hypo. Your doctor can advise whether you need to adjust your insulin, food, or timing around exercise.

Never skip insulin to lose weight

You should never reduce or skip insulin to lose weight unless your doctor has specifically advised a change in dosage.

Not having enough insulin can cause high blood glucose and ketones, which can lead to diabetic ketoacidosis. This can be life-threatening and needs urgent treatment.

Tracking your weight can be helpful, but it should not be the only thing you look at. You may also want to track your blood glucose patterns, hypo frequency, time in range if you use a glucose sensor, waist measurement, fitness, energy levels, and how your clothes fit.

This gives you a better picture of whether your weight loss plan is working safely. Try not to judge progress day by day. Weight can naturally go up and down because of food, fluid, hormones, salt intake, and exercise.

Speak to your diabetes team before starting a new weight loss plan, especially if you plan to change your carbohydrate intake or increase exercise.

You should also get advice if you are having more hypos than usual, regularly high blood glucose, unexplained weight loss, ketones, vomiting, extreme thirst, needing to pee more often, stomach pain, drowsiness, confusion, or fruity-smelling breath.

These can be signs that you need urgent help, especially if ketones are present.