What is the modified Atkins diet?

The modified Atkins diet (often abbreviated in the literature as “MAD”) is a change to the traditional “classic” ketogenic diet to make it less restrictive. Along with the MCT (medium chain triglyceride) diet and LGIT (low glycemic index treatment), it is one of three “alternative diets” used to treat patients with epilepsy.

Its history goes back to the early 2000s.  Some families who had used the ketogenic diet for many years eventually stopped weighing and measuring foods. They had noticed that ketones still remained high and seizures stayed under control. It was first formally studied in children and adults who had never tried the ketogenic diet at Johns Hopkins Hospital by Dr. Eric Kossoff and colleagues in 2002. The first paper on this diet was published in 2003. A larger series of 20 children was published in December 2005.

This diet is now over 14 years old with greater than 500 patients published to date.  Studies show it is very similar to the classic ketogenic diet in efficacy.

How is it different from the Ketogenic Diet?

Although the foods are very similar, there are key differences between the modified Atkins diet and the ketogenic diet.

  • First, with the modified Atkins diet, there is no fluid or calorie restriction or limitation.
  • Although fats are strongly encouraged, they are not weighed and measured. Most patients will consume plenty of dairy and oils.
  • One of the biggest differences is that there are no restrictions on proteins. Typically 35% of calories for a patient on the MAD come from protein.
  • Foods are not weighed and measured, but carbohydrate counts are monitored by patients and/or parents.
  • It is started outside of the hospital and the person does not need to fast before starting the diet.
  • Lastly, foods can be eaten more freely in restaurants and outside the home, and families (and neurologists!) can do it as well.  

The diet is a "modified" Atkins diet as it allows for less carbohydrates than the traditional Atkins diet (15 to 20 g/day) and more strongly encourages fat intake.  Please remember that no diet should be tried without a neurologist involved.

Who will it help?

It seems to help similar numbers of patients as the ketogenic diet (40-50% with greater than 50% seizure reduction, including approximately 15% seizure-free). It works for men and women equally and is being used actively in adolescents and adults. Like the ketogenic diet, it is mostly used for patients with daily seizures who have not fully responded to medications.  It is under study for regions of the world with limited resources for which the classic ketogenic diet would be too difficult or time-consuming as well.

What is it like?

  • Lots of high fat foods such as bacon, eggs, mayonnaise, butter, meats, heavy whipping cream, and oils are encouraged.
  • Certain fruits, vegetables, nuts, avocados, olives, and cheeses are used as well.
  • Fluids such as Fruit2O, diet soda, and other flavored waters are favorites of many patients. Fluids are encouraged and help avoid side effects.
  • Carbohydrates are limited but the patient (or parents) chooses what to eat.  For example, they can choose blueberries or chocolate (but will get more quantity with blueberries…).
  • Compared to a patient on the classic ketogenic diet, the biggest differences reported are 1) more food (higher calories) and 2) more proteins.
  • Many patients will supplement the diet with ketogenic products (e.g. formulas, shakes, baking mixes, and pre-made breads).  One study showed improved benefit in children when a ketogenic diet formula was used as a supplement for the initial month.
  • It's still not easy though, and most families need help and support.

What happens first?

  • You should talk with your neurologist and dietitian about how to start the diet and if it's the right decision.
  • Once you decide, lab work is usually obtained, and ketone strips are prescribed.
  • Carbohydrates are limited (15-20 grams per day) and the foods change overnight (making it hard to transition).
  • Medications are usually left unchanged (and most patients on the modified Atkins diet are also on some medications). If medications are in liquid forms, they are usually changed to tablets to decrease carbohydrates.

Does it work?

In studies so far, yes. About half had a 50% reduction in seizures after 6 months. Many were able to reduce medications.

Can adults do it?

  • Absolutely, adults with epilepsy are one of the fastest growing groups of patients starting diets today.  Ask your neurologist to help (or refer you to an adult epilepsy diet center).
  • Outcomes are largely similar to children, with similar side effects.
  • Most adults remain on medications, probably a higher percentage than children on dietary therapy.
  • Speak to your neurologist first if you have high cholesterol, high blood pressure, heart disease, liver or kidney disease, a history of kidney stones, nutritional deficiencies, or are considering getting pregnant.

Are there any side effects?

  • Some children and adults lose weight. This can be a good thing though for those who were overweight in the beginning.
  • Some patients have had increases in cholesterol.
  • Occasionally, the change to this diet and the resultant ketosis can make patients feel ill and not want to eat or drink.
  • Kidney stones are unusual and oral citrates are typically not prescribed (unlike the ketogenic diet).
  • For all these reasons, the modified Atkins diet should only be done with physician supervision.

How is the patient monitored over time?

  • A dietitian should keep track of weight and height periodically, as well as calorie intake in case there is a problem. We recommend dietitian involvement either from the beginning (ideally) or after 3 months if the diet seems to be working to help keep the patient on it.
  • Drs. Kossoff and Cervenka recommend blood and urine monitoring every 3 months, and checking urine ketones once or twice a week while on the diet.

Can the diet ever be stopped?

Yes, if a patient is seizure-free for a period of time (e.g., 2 years), the diet can sometimes be stopped successfully.  In most seizure-free adults, it is not stopped (due to driving and other benefits). Similarly to the ketogenic diet, if it's not helpful, it should be stopped, too.

What is the future of the modified Atkins diet?

Lots of studies continue to occur, several evaluating this newer diet in comparison to the classic ketogenic diet. Other studies underway include:

  • Improving efficacy and safety in adults
  • Expanding usage in developing countries
  • Adding supplements to improve efficacy
  • Using MAD for “milder” epilepsies not often treated with the ketogenic diet (e.g. childhood absence epilepsy, juvenile myoclonic epilepsy)
  • Using MAD for conditions other than epilepsy (e.g. autism, brain tumors, and dementia).
Authored By: 
Steven C. Schachter, MD
Joseph I. Sirven MD
Reviewed By: 
Eric Kossoff MD
Friday, November 13, 2020