What is the low glycemic index treatment (LGIT) for epilepsy?
The low glycemic index treatment (LGIT) is a form of dietary therapy for epilepsy.
The LGIT allows more carbohydrate than the classic, medium-chain triglyceride (MCT) or modified Atkins ketogenic diet therapies. Children can eat 40 grams (g) to 60 g of carbohydrates per day. However, all the carbohydrate the child eats must have a low glycemic index (GI). Glycemic index is a measure of how much a particular food raises blood glucose (sugar); low glycemic index foods raise the blood glucose more slowly than high glycemic index foods.
Many different factors affect the GI of a food. Starchy and sugary foods, such as potatoes and white bread have a high GI. Foods high in fibre that are not highly processed, such as wild rice or whole grain breads tend to have a lower GI.
The LGIT still contains more fat than a "normal" diet. About 60 per cent of calories in the diet come from fat, and about 20-30 per cent of calories from protein.
The LGIT was first described as a treatment for epilepsy in 2005, after doctors observed that some children had many more seizures after eating high-GI foods. Stabilizing blood glucose seems to help control seizures in some children.
Benefits of the LGIT
The LGIT has been shown to reduce seizures in many children, sometimes by more than 90 per cent, however it does not work for every child. The LGIT is easier to follow than the classic ketogenic diet and offers a wider range of food options. Children can order food that is appropriate for the diet in restaurants and cafeterias. Although research is still limited, children on the LGIT seem to have fewer side effects than children on the classic ketogenic diet.
However, this treatment may not always lead to a state of ketosis, which is usually necessary for seizure control. It may take a few months to see if the child responds to this treatment. If not, it might be recommended that the child switch to another diet therapy.
If the LGIT is successful in controlling seizures, there is no maximum length of time that the treatment can be used. The length of time that a child’s seizures are managed with the LGIT is decided by the family, child and ketogenic diet therapy team.
Limitations and side effects of the LGIT
Studies have found few side effects from the LGIT. Side effects may include constipation, changes in blood chemistry and weight loss.
Your child will need to take specific vitamin and mineral supplements. Your child's doctor and dietitian can advise you on these.
Ask your child's ketogenic diet therapy team to explain all possible side effects, what you should watch for and what action you should take for each one.
Points to consider before trying the LGIT diet
- More foods are allowed on the LGIT diet than with the classic ketogenic diet, but the diet is still very restrictive. The diet controls the type and quantity of food you child is allowed to eat.
- The LGIT will not work unless it is followed carefully, and some children are unable or unwilling to follow it.
- Meals and snacks can be time-consuming and tedious to prepare. This usually gets easier as families adapt to the new routine.
- It might not work for some children, no matter how closely they follow the diet.
- Children must be followed closely by a doctor during treatment with the diet.
Starting the LGIT
Before starting the LGIT, your child will need to be seen in a ketogenic diet clinic for a full evaluation by the ketogenic diet therapy team members. Your child will need a physical examination, with measurement of his height and weight and several different blood and urine tests.
The team will also ask for a history for your child’s diet, including:
- What they eat at home
- What they do and do not like to eat
- How much they eat
- Whether you see any problems feeding them the diet
- Whether your family has any cultural or religious food restrictions
Your child will usually start the LGIT as an outpatient. Your child does not need to be admitted to hospital, but it is important to stay in close contact with your child’s ketogenic diet therapy team.
Learning to use the LGIT
Your family will meet with a dietitian to learn how to count carbohydrates, read food labels, identify sources of carbohydrate, estimate the GI of various foods, plan menus and calculate portion sizes. The dietitian will explain which vitamin and mineral supplements your child will need and where to buy them.
They will also help you with strategies for dealing with problems you may encounter while your child is on the diet, including constipation, acidosis and weight loss.
A nurse will teach you how to measure your child’s urinary ketones, and review how to manage possible medical complications.
Before starting the diet at home, it is a good idea to become comfortable with the concepts of the diet and buy enough food to allow you to follow the diet for a few days.
Using the LGIT at home
Following the diet closely is very important to ensure your child has given it the best chance to work and to see if it can control your child's seizures. It may take several months to see the effects of the diet. If you find the diet too restrictive, speak to your dietitian and doctor to discuss how to make it easier to use. Changes to the diet could mean changes to food content, quantity or scheduling.
Unlike the classic and MCT diets, other family members can also follow the LGIT if they wish. This may help children feel less isolated and may help them follow the diet more easily.
Follow up appointments for LGIT
Children treated with the LGIT require frequent monitoring by their health-care team. They are seen by the ketogenic diet therapy 1 month after starting the treatment and then every 3 to 6 months.
Check-ups will include measurements of weight and height, review of urine and blood tests, discussion of your child’s seizures and side effects of the diet, and a medical examination.
Between appointments, you will need to keep track of your child's seizure activity and body weight. Record this information in a diary or your phone so that you can bring it with you to your child’s next clinic appointment.
Some medications, including over-the-counter cough and cold medicines and intravenous (IV) fluids, have sugar (carbohydrates) in them. The dietitian will explain how to avoid medications with carbohydrates. Tell all doctors and pharmacists involved with your child’s care that your child is on the LGIT.
Discontinuing the LGIT
If the diet has kept seizures well under control for several years, your child may be slowly taken off the LGIT with guidance from your child's ketogenic diet therapy team. If it is not working, the diet may be slowly discontinued or your child’s ketogenic diet therapy team may suggest switching to a different diet therapy. If the diet continues to work well for your child’s seizures and your child has no negative side effects, the diet can be continued for longer. Some children will transition to adult health care with the ketogenic diet therapy.