What is the Keto Diet and How Does it Work?

By Amanda Bower, MS, RD, LD

The benefits of good nutrition are widely agreed upon in the medical field. The food patients eat affects their health in the moment and years down the road. Eating healthy can improve clinical outcomes, and reduce the risk of many chronic diseases.  

Although many people associate chronic disease and nutrition with diabetes and heart disease, chronic disorders including epilepsy, Alzheimer’s and autism have been found to benefit from diet therapy or modification. The ketogenic diet has been used to treat seizures/epilepsy since the 1920’s and 1930’s, but new literature is suggesting this diet can be used to delay the onset or progression of Alzheimer’s disease and behavior improvement in autistic children. 

The Basics

The ketogenic diet is designed to stimulate the metabolism of fasting. 

Carbohydrates (“carbs”) are the main source of fuel for the brain, heart, muscles, and other organs. When a fasting person has burned up carbs, he or she then begins to burn stored body fat for energy. By providing dietary fat from foods, the ketogenic diet allows a person to maintain this fat-burning metabolism as the primary source of energy over an extended period.

People on the ketogenic diet strictly limit their carb intake. Carb sources are fruits and non-starchy vegetables. Instead, common ketogenic foods include heart healthy fats such as nuts, seeds, avocado, coconut oil, olive oil, butter, heavy cream, mayonnaise and bacon, and protein such as chicken beef, fish, eggs, peanut butter and cheese. 

Unlike carbs, fat is not burned completely but leaves a residue in the form of ketones bodies. These ketone bodies build up in the blood, and give this diet its name.

The ketogenic diet promotes a specific balance of high fat (65-90% of total calories) and low carbs (3-15% of total calories) with moderate amounts of protein. This diet must be undertaken with the close supervision of a physician and a trained dietitian. All ketogenic diet meals are measured and weighed on a gram scale and prescribed in a ratio (3:1, 4:1). 

The medical ketogenic diet is not the same as the trendy diet known as “keto,” often used for weight loss. Types of medical Diet Therapy include Classic Keto Diet, Modified Keto, MCT oil diet, Modified Atkins and Low Glycemic Index. 

Supplements like a daily multivitamin, calcium and vitamin D are necessary for all ketogenic diet patients, as the foods on the diet are limited and deficiencies may occur. 

Does it work 

Multiple studies have shown that slightly more than half of children on the ketogenic diet will experience a decrease in seizures by 50%. About one third will have a >90% improvement, and about 10% to 15% will be seizure-free. 

Preliminary studies are also finding that the ketogenic diet may slow cognitive decline or even improve cognition in patients with Alzheimer’s disease. Research remains ongoing for the efficacy of the ketogenic diet for autism, though one published study does show improvement in symptoms. 

Complications/Side Effects:

  • Changes in bone density
  • Constipation
  • Kidney Stones
  • Hypoglycemia
  • Hyperlipidemia
  • Reflux
  • Fatigue
  • Nutrient deficiencies

The ketogenic diet has the power to heal.  Research on the ketogenic diet is being published at a rate never seen before. The diet was originally studied for its effects on epilepsy but is now showing promise for a multitude of other illnesses that have an underlying metabolic dysregulation. The Ketogenic diet may be a great tool to improve health outcomes. 

Visit our Registered Dietitian page to learn more from the experts.