The Really Useful Ketogenic Diets Book has been written and produced by The Daisy Garland.  It is a user-friendly guide full of essential information and FAQs. The guide is specifically for families whose children are following the ketogenic diet to treat drug-resistant epilepsy. The ketogenic diet is a medical-led treatment and should never be undertaken without the involvement and permission of your neurologist, and the close guidance and support of a specialist ketogenic dietitian.

For a downloadable and printable copy please click on the purple bar below.

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The information contained in this publication is not permitted to be reproduced, in whole or in part, without prior written permission from The Daisy Garland charity. 

How will I manage illness whilst on the ketogenic diet?

During illness we aim to maintain ketosis if at all possible, but it is more important for your child to get well again.

It is quite common for ketone levels to drop just before your child becomes unwell. This is due to a combination of factors including the infection and decreased activity levels. During times of illness if you become concerned about your child, it is important to contact your GP or ketogenic diet team.

Each hospital will have their own specific guidelines and policies on managing illness, which will be given to you on commencement of the diet. The following are guidelines only, giving general advice on managing illness whilst on the ketogenic diet.

The information in this section has been adapted from documentation written by H Chaffe, L Neal and N Edwards for KetoPAG.

Vomiting and diarrhoea

Contact your ketogenic dietitian to make them aware that your child is unwell.

The diet may need to be stopped temporarily and it is important to maintain an adequate fluid intake. Offer frequent drinks such as water or sugar-free squash. If symptoms continue for 24 hours your child should see your GP who might recommend an oral rehydration solution to replenish the body’s electrolytes, these will contain carbohydrate and your child’s diet will need to be adjusted accordingly.

Monitor for signs of low blood sugar and/or excess ketones.

• Reintroduce the diet slowly once your child has stopped vomiting. If your child is unable to take solids or KetoCal, if you have an emergency ketogenic milkshake recipe, this can be used. Give this as small sips throughout the day.

• If initially your child is unable to take the full quantity of food or milkshake, do not worry. It is more important during this time of reintroduction to ensure that adequate fluids are being given in the form of sugar-free drinks.

• The amount of food or milkshake can be increased slowly and once your child is feeling better and their appetite has returned they can resume their normal ketogenic diet plan.

• Please contact your ketogenic diet team if the emergency ketogenic milkshake has been given for 2 days. This milkshake is not for prolonged use, as it does not contain adequate nutrition.

How do I reintroduce meals after vomiting or diarrhoea on the ketogenic diet?

• For the first day or two start by giving half the usual amounts of the meal. Alternatively, you can give your child their ketogenic diet snacks.

• If your child is unable to complete their full meal, mix all meal constituents together. This means that the food eaten is in the correct ratio of fat, protein and carbohydrate regardless of the quantity eaten.

• If your child is unable to tolerate full-fat meals due to continued vomiting or diarrhoea contact your dietitian who may recalculate your meals for a short time.

Our Daisy Garland Dietitian was always on hand with excellent advice whenever our child was unwell.

For the MCT diet

If using Liquigen, the amount used may need to be reduced to half and then increased over the next 2 to 3 days to full strength. If diarrhoea is a continuing problem, the Liquigen may need to be introduced at quarter strength and then increased to the full amount over 4 to 5 days. This can be discussed with your dietitian.

For tube feeds

When reintroducing gastrostomy or nasogastric feeds, initially use half-strength feed for 24 to 48 hours, then gradually build to full strength as tolerated over a few days.


• Use sugar-free paracetamol. Suitable formulations will be advised by your ketogenic diet team.

• Sugar-free ibuprofen contains a small amount of carbohydrate but it may be used if there is no other alternative.

• Maintain adequate fluid intake by offering sugar-free fluids without restriction. If your child will eat as usual, then the diet can be maintained. However, you may prefer to use the milkshake recipe as this can be sipped throughout the day.

• It is important to contact your GP as you would normally, if you are worried about your child’s health.

• Any other medication, such as antibiotics, should be sugar-free and sorbitol-free if possible.

We found paracetamol suppositories so much easier to administer when our daughter was unwell. Our GP was able to prescribe these - Sara.


Discuss this with your dietitian as some dietary changes may be possible. Try increasing high-fibre foods such as Chinese leaf, rhubarb, spinach, berry fruit, avocado, psyllium husk, broccoli, green beans, kiwi fruit and nuts. Flaxseed is also useful in managing constipation. An increase in fluid intake can also be helpful.

The following treatment options for constipation could be prescribed:

• Movicol Paediatric Plain can be helpful when the stool is soft but difficult to pass. Mix the Movicol with water and add to sugar-free squash or you can add the mixture to food. It helps to keep the stool soft to make it easier to pass.

• Resource Optifibre is an alternative, which is suitable for younger children. It is a fibre supplement and you must drink plenty of water to keep the stool soft.

Please note: Lactulose is often not recommended on the diet as it is known to have some impact on ketosis.


• If your child is unwell with worsening seizures, check their ketones and contact your local medical team. It can be quite common for seizures to worsen slightly on reintroduction of the diet for a short period. Contact your ketogenic diet team if you are concerned.

• Emergency medication for management of seizures can be given as normal.

• If taken to hospital and requiring intravenous fluids, please ask the nursing and medical staff to avoid glucose or dextrose. Your child can have normal saline or plasmalyte. The nurses will then need to monitor ketone and glucose levels 4 hourly.

• Oral/IV med stickers available free of charge and on request from [email protected].

Low blood sugar

• Blood sugar levels are usually lower on the ketogenic diet compared to when following a ‘normal’ diet. This is not a problem unless symptoms develop.

• Symptoms of low blood sugar – sweating, jittery, cold and clammy, confused or aggressive.

• You may be given a blood glucose monitor to check levels at the start of the diet and during illness.

How to treat low blood sugar symptoms

• You will be provided with a specific plan to manage low blood glucose levels by your ketogenic dietitian. This could include giving 50ml of fruit juice which provides 5g of carbohydrate.

• If concerned about low blood glucose levels please seek medical attention.

Excess ketosis or high ketone levels

Ketone levels can occasionally become too high. You may find that this happens when the diet is first started, when there has been a change in the diet or during illness. You will be provided with a plan from your ketogenic diet team which will tell you at what level to treat ketone levels e.g. over 6 mmol/L.

Symptoms of excess ketosis:

• rapid, panting breathing

• increased heart rate

• facial flushing

• irritability

• vomiting

• unexpected tiredness

How to treat high ketone levels

• You will be provided with a specific plan to manage low blood glucose levels by your ketogenic dietitian. This could include giving 50ml of fruit juice which provides 5g of carbohydrate.

• If you are concerned about repeated high levels of ketosis then discuss this with your dietitian.

• If you are concerned about illness and associated excess ketosis, please seek medical attention.

Low ketones

• Before your child becomes ill, ketone levels may fall.

• Excess fluid intake can effect ketone levels in the urine.

• Ketone levels may fall if additional carbohydrate has been taken (food or medication).

• After exercise, including swimming, ketone levels may be low therefore give a ketogenic snack soon after if possible. If you are regularly seeing dips in ketosis after exercise, please contact your dietitian as the dietary plan will need adjustment.

• Steroid medication will effect ketone levels (discuss with your GP).

• Please contact your ketogenic dietitian to explore other reasons why ketones may be low i.e. constipation, change in formulation or doses of medications, teething, rapid weight gain or loss.

Irritability and a rash on her chin were a sure sign our daughter’s ketones were too high. Pureed apple helped bring them down so we kept a pureed fruit pouch to hand - Rebecca.