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Table 3 Themes from interviews and focus group with supporting transcripts

From: Ketogenic diet benefits body composition and well-being but not performance in a pilot case study of New Zealand endurance athletes

Positive themes Negative themes
Physical recovery Loss of power during exercise/training
 “The recovery each time was amazing. I would go for a 4–5 h run then be able to mountain bike the next day, just to be able to do it without sore muscles”.  “The next day after a 4-h run I could have got up and done it again - my legs weren’t tired or sore”.  “Certainly I’ve had the recovery benefits I felt fine to go out the next day and do stuff I didn’t feel the muscle soreness I would have expected”.  “I don’t feel sore”.  “I was surprised that I could run comfortably for that long so I think the recovery was huge I never felt this, it’s unheard of”  “It was embarrassing to the point where I just got to the point where you just don’t have any energy”. (weeks 1–5)  “I got too tired and I got to the point where I might have had some big runs, 4 or 5 h runs and wake in the night before hand, worried about it. I’d think, how am I going to do that tomorrow… it’s going to be hard”. (weeks 1–5)  “The lack of power, I just couldn’t get up the hill.” (weeks 6–10)
Negative symptoms (weeks 1–3)
 “I hadn’t been for 4 days and I was starting to get bound up”. (constipation).  “One of the downsides is that I had cramps, massive cramps”.  “I may have seemed a bit irritable for a while. People close to me realised I was down and I’m pretty good at hiding that but people picked it up”.
Enjoyment of this way of eating
 “It’s given me the freedom to eat the things that I stopped eating for a long time because I thought it was a no-no”.  “Not feeling hungry has been amazing”. (X2)  “Not being bothered about food, you know food doesn’t bother me anymore, as before I had a meal and 3 h later I’d feel irritable if I didn’t eat”.  “It’s been fantastic for me having food I couldn’t for a long time and I really enjoy it, the flavour, for me the reason why I want to carry on with this way of eating is because I actually enjoy it, I enjoy it far more than my previous diet”.
Food regime boredom
 “Bored with the food regime, actually I’m back on fruit …”  “…but I am starting to get sick of the diet plan”.  “You can’t even free load in your veggies.”
Weight management
 “Being able to shed that 5 kg was definitely a benefit”.  “The benefit now of me being able to understanding how to manage my weight, that’s been a real effect, actually that’s been for all of us”.
Feel better overall (well-being)
 “My skin hasn’t been this good since I can remember”.  “My prostate, a million times better because I can sleep”.  “The other thing I noticed is my tinnitus is a lot better, I can’t hear the ringing in my ears I used to have”.  “Just general health - I just feel better, I need less sleep”.  “I noticed that I didn’t fart for 2 months, no gas”.  “Yes, no gas, that’s the same as me.”  “I feel sharper mentally”.  “Food used to dictate my moods, and now it doesn’t”.  “Positive skin, I have a facial every 6 weeks, I didn’t tell the facial lady what I was doing and she said to me what’s happened to your skin? No extractions in the last 8 weeks, no blockages”.