Can You Fine-Tune the Ketogenic Diet?

Ketogenic foods

Epilepsy News From:

Monday, March 9, 2015

In this month's issue of Keto News, I'm profiling an article written by our group that was published late last year in Journal of Child Neurology. Although entitled, "Dietary and medication adjustments to improve seizure control in patients treated with the ketogenic diet," it could be better titled as perhaps, "Can you fine-tune the ketogenic diet?" This is an important topic and a research idea I've had for as long as I've been working with this unique therapy. 

Unlike medications, in which a dose can be increased, timing of medications changed, or brand name (vs. generics) substituted, the diet has many more possible ways to tweak its efficacy theoretically. I was always taught that if the ketogenic diet wasn't working, it was critical to try and "fine-tune" it. Many families will email me and ask me this question, some even travelling to Baltimore for a second opinion. Our Ketogenic Diets book devotes an entire chapter to the topic, but with scarce references...

So what are the chances of diet changes really making a difference?

In order to answer this question, I had an eager medical student, Jessica Selter, review charts (and emails and phone calls…) from 200 consecutive children started at Johns Hopkins on the ketogenic diet over 6 years. This was a gargantuan task – Ms. Selter reviewed charts to see if changes made to the diet (or eventually medications) led to a documented improvement in seizures. She found that there were 12 changes commonly made:

Increasing the ratio Adding carnitine
Decreasing the ratio Adding MCT oil
Increasing calories Spacing meals
Decreasing calories Fasting the child and restarting the diet
Intermittent fasting Removing artificial sweeteners
Changing medication dose Adding a new medication


What were the results of these changes?

First the good news. About half the time (42.4%), making these changes led to at least a 1% additional improvement in seizures. Nearly 1 out of 5 times, the change led to a significant additional improvement (>50%). Even after many months (or years) of continued ketogenic diet use, these changes still had an impact. Children who were younger were more likely to see benefit, suggesting maybe those children do need their diet "fine-tuned" versus older patients. No one diet modification was best, but changing calories had the least impact.

What was the bad news? Only 3.7% became seizure-free with a diet change. Also, changing anticonvulsant medications was somewhat more likely to be successful than diet changes (24% vs. 15% having an additional >50% reduction in seizures). 

How do I interpret these results and then counsel families?

  • I tell them that our dietary changes for children on the ketogenic diet do work…but only modestly.
  • I'm willing to try to fine-tune the diet even after years of use, making one change at a time, but I'm realistic with families about medications being more likely to cause additional benefit.
  • I remind them that anticonvulsant medications and the diet are often "partners" and they shouldn't be afraid to add a new drug – some of the newer drugs have unique ways in which they work and could work in tandem with the ketogenic diet possibly.
  • If they've tried many of the above diet modifications and seizures haven't gone away, it's not their fault.

Hopefully this research study will interest other researchers in ways to make the ketogenic diet better and more effective: perhaps there are ways to fine-tune the diet I'm not aware of that would be superior?  Let's fine out!

Authored by: Eric Kossoff MD on 3/2015

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