The ketogenic, or keto, diet is a very-low-carb, high-fat diet that has been shown to deliver several health benefits.

In recent years, interest in the use of the keto diet to help manage certain health conditions in children, including epilepsy and brain cancer, has increased.

While the keto diet is relatively safe for adults, this may not be the case for children and teens unless it’s prescribed by a health professional for medical reasons.

This article reviews the safety of the keto diet for children and teens, as well as its potential uses and downsides.

Since the 1920s, the keto diet has been used to treat children and adolescents with refractory epilepsy — a seizure disorder.

Epilepsy is defined as refractory when treatment with at least two traditional antiepileptic drugs has failed.

In several studies in children with this condition, following a keto diet decreased seizure frequency by up to 50% (1).

The anti-seizure effects of the keto diet are thought to be the result of several factors (1, 2, 3):

  • reduced brain excitability
  • enhanced energy metabolism
  • brain antioxidant effects

This way of eating has also been used in conjunction with traditional chemotherapy to help treat certain types of brain cancer in adults and children (4, 5, 6, 7).

Nearly all tumors depend on carbs (glucose) for energy. The keto diet has been said to starve tumor cells of the glucose they need, thus helping reduce tumor size when combined with other forms of treatment (8).

While several animal studies have been conducted and human studies are ongoing, further data is needed to establish the long-term effectiveness of the keto diet for treating brain cancer in children.

Over the past 20 years, new versions of the keto diet have emerged, some of which are less restrictive yet provide many of the same benefits. This includes the modified Atkins diet (2).

While the therapeutic keto diet restricts calories, carbs, and protein, the modified Atkins diet is more liberal when it comes to overall calories, fluids, and protein. This allows for more flexibility while offering similar benefits (9, 10).

Keto diet for epilepsy management

When implementing the keto diet to help manage epilepsy in children, a specific regimen is followed to ensure consistent results. The diet is typically administered under the supervision of a physician, registered nurse, and registered dietitian.

Before starting the diet, a registered dietitian is consulted to determine the child’s nutritional needs and establish a meal plan. Traditionally, the diet comprises 90% fat, 6–8% protein, and 2–4% carbs (11).

The program often begins in a hospital or intensive outpatient setting for the first 1–2 weeks. On day one, one-third of the total calorie goal is achieved, followed by two-thirds on the second day, and 100% on the third day (11).

In a clinical setting, all-in-one formulas containing the necessary nutrients may be used to initiate the keto diet for the first week, after which whole foods are gradually reintroduced (11).

The child and parents are thoroughly educated on the diet, and the necessary resources are provided before they return home.

The diet is usually followed for about two years, at which point it’s either discontinued or transitioned to a modified Atkins diet to allow for more flexibility (1).

Studies have also found that the keto diet can be safe and effective for infants and toddlers with refractory epilepsy (12, 13, 14).

Still, as these populations are extremely vulnerable, the decision to use this diet must be made on an individual basis by a physician.

Summary

The keto diet is used in children and adolescents under close medical supervision mainly to help treat refractory epilepsy and brain cancer.

As with any diet that restricts one or more food groups, the keto diet may have certain adverse effects.

The risk of side effects increases in children and adolescents, as their growing bodies are more susceptible.

The main potential side effects associated with the keto diet in children are (15, 16):

In a therapeutic setting, proper measures are taken to minimize adverse effects.

Medical guidance is mandatory when the keto diet is used to help treat epilepsy or cancer in children and adolescents. Without it, the risk of serious side effects increases, outweighing any potential benefits.

Summary

Considering the restrictive nature of the keto diet, the potential for adverse effects is high in children and teens. Some of the main side effects are dehydration, low blood sugar, and impaired growth.

Children are at a phase in their life in which they’re growing at an increased rate, as well as developing their food preferences.

During this crucial time, adequate nutrition is important. Overly restricting dietary intake of certain food or micronutrient groups, as is done with the keto diet, may impact growth and overall health.

Following a keto diet would also affect your child’s cultural experience when eating with peers and family.

Given the high rates of childhood obesity, many children may benefit from a reduced carb intake. However, the keto diet is too restrictive for the average healthy, growing child (17).

Summary

Given the restrictive nature of the keto diet, as well as its potential effects on growth and food culture, it’s not recommended for healthy children.

Adolescents are at a time in their lives in which body image may become increasingly important to them.

Adhering to an overly restrictive diet can lead to unhealthy behaviors and significantly affect their relationship with food.

These unhealthy behaviors could lead to eating disorders, which are prevalent in the adolescent population (18, 19).

Though one study suggests that the keto diet may be effective for weight loss in teens, many other eating patterns are less restrictive and easier to follow in the long term, such as whole-foods-based diets (20, 21, 22).

The same idea applies to children. While the keto diet can aid weight loss, other eating patterns require less restriction and don’t carry the risks associated with the keto diet (20).

Unless a keto diet is recommended and guided by a physician for medical purposes, it’s inappropriate for most children and teens.

Summary

Following a restrictive diet like keto can lead to unhealthy behaviors surrounding food and may affect growth in children and teens. Therefore, the keto diet is not recommended for weight loss in this population.

The keto diet is used alongside traditional therapies to treat children and adolescents with epilepsy and brain cancer.

Medical guidance is mandatory and may help minimize adverse effects like dehydration and digestive issues.

Due to its restrictiveness, the diet is not appropriate nor safe for most healthy children and teens.