Potential benefits of a ketogenic diet to improve response and recovery from physical exertion in ME/CFS, 2020, Cossington et al

I'm glad that they are looking at this; it would be good to know if the ketogenic diet helps, and we need more teams looking at exercise physiology.

I'd have to read this paper a lot more carefully to understand it. But, I like

• that the group has done a genuine feasibility study to work out their protocol for a larger study.
• they use the term ME/CFS and the introduction acknowledges the impact of the disease
• that Jo Cossington got funding from the Nutrition Society Summer Studentship and may well be interested enough to do more studies of ME/CFS physiology
• that there's obvious care for the participants
• that a professor, Professor Helen Dawes, appears to have taken an active part in the research

I don't think we can conclude much from such a small pilot study (PwME/CFS n=3; control n=3), other than this team has made a decent start.

Can someone explain to me what they mean by the bit in bold? 'Glycolytic' is burning sugar , isn't it? But aren't they saying that the glycolytic pathway is broken?

And I'd like this bit explained too.

One suggestion:

They had a nutritionist query each participant about what they ate the day before. I think they'd do better to teach participants how to use a food logging app, and have people record what they eat as they go.

Edited for formatting

 

First of all. more studies using diet as intervention, please! Especially with measurements like these on exercise performance

@Hutan I believe they are refering to glycolysis when they are talking about "glycolytic energy production". In the introduction they mention increased lactate due to glycolysis. But if that's the case, I'm not quite sure what normalization they are talking about. Neither the lactate measurements or RER makes me think anything has been improved.

I'm not sure about the second bit you want explained. What the RER values mean or what RER you would expect at certain levels of exertion? OR something else entirely?

Re the 24h recall, it's one of the easiest ways to get the data fast. Which might have been of importance if there were some deadline that had to be met. I'm not particularly fond of them as they rely on recall and people tend to overestimate healthy foods and underestimate unhealthy foods, in this case high carbohydrate foods (but this would also be the case if partcipants had a food diary, they could just not register something that did not adhere to the diet). I'm glad they checked for this using ketones.

I have some more comments on this, but I have other cognitive tasks to perform today so I can't go into much detail right now, but:
- I would wish for the pwME and controls to be better matched
- In the introduction they say susceptibility to oxidative stress may be a factor in abnormal metabolism in pwME, and then they don't discuss the effects a ketogenic diet can have on this?
- The wash out period seems short, also the time for the body to get used to fat as a primary energy source
- More data on the diet, the calories alone and macronutrients are perhaps fine for showing adherence to a ketogenic diet, but for therapeutic use there are a few things to consider (also, the two controls that had dietary data had reduced their caloric intake by a lot.. while the pwME had increased it)
- Feeling better on a dietary intervention that you believe will make you feel better does not actually mean you are better..

I'm not anti-ketogenic diet per se, I believe they have their uses, but I know they do not work for me and some of the negative effects may hit pwME harder than a healthy person.

 

Yeah, it was this that puzzled me mostly.

I guess they just grabbed people close to hand for this trial run.

Yes, I wondered about that. If the ketogenic diet was having an effect on inflammation say, then maybe a longer time might be needed for the full benefits to show? Maybe they intend to have a longer period when they do the actual trial?

Yes. I wasn't sure if the mild benefits I felt were from the ketogenic diet or the fact that I was eating a hell of a lot of celery and nuts to get the right amount of fibre every day, which I was tracking carefully. It's easy for there to be a lot of noise in the data, with some people in ketosis but eating rubbish, and others eating more whole food than they might have otherwise.

 

Not unlikely. For a summer project there are a lot of limitations.

Yes. And the same goes for negative effects, like sleep issues. And it could also be closely linked to diet quality, like you say people can be in ketosis and eat rubbish. I'm not sure if there will be a larger study building on this assessment, but it would be interesting.

Exactly. Not everyone thinks about getting enough fibre, I'm happy you did