I have had CFS since my teens, and especially strongly in two periods (including right now).
From the beginning, I knew that food played a role in how well I do. The type of food plays a role, as does when I eat, and – as I discovered more recently – having some minimal fat reserves.
Type of food. I tend to do best when I eat mostly vegetables and meat, with smaller amounts of grains and fruit, and minimal to no dairy and sugar. The less processed the better. And I prefer organic and locally produced food. I am from Northern Europe, and I notice I do well on traditional Northern European foods. Perhaps it’s genetics, or just what my body is used to, or the climate, I don’t quite know.
I especially like warm food that’s delicious and easy and quick to prepare. Slow cooked stews with bone broth is a favorite.
When I eat. I tend to eat relatively frequently. My main meal is often breakfast, and it’s often vegetables and meat. Lunch and dinner are typically similar. Although I do mix it up according to what I notice I am drawn to. It’s good to not be too strict. (For instance, I had muesli with kefir a couple of days ago and it felt right and good then. And I do sometimes eat chocolate.)
Fat reserves. I have been slim to skinny my whole life, and unable to put on weight even when I have intentionally tried to. This spring, I did a combination of Vortex Healing and using an app in order to put on more weight, and it worked within a week. (The Vortex Healing was for my digestive system and to support my body in absorbing and making use of nutrients.)
I am now up to 84kg (184cm tall) and have a minimal to moderate layer of fat on my body for the first time. It feels like an important and helpful buffer for me. I used to have energy crashes if a meal was delayed or I missed a meal. Now, that doesn’t seem to happen anymore. Joey Lott and others talk about the importance of eating enough in order to deal with and perhaps recover from CFS, and that fits my experience as well.
Additional notes. As I mentioned above, I am not terribly strict in my diet. Now and then, I do eat some grains, some dairy (cheese, kefir), and some sugar (mostly in the form of chocolate). I also find that butter seems to really help me, so I tend to melt butter on most warm meals. I should also say that I do some strength training and typically walk a good deal, so I try to stay as fit as I can within the limitations of having CFS.