Some weeks ago, i began the monumental adventure of reading the Hyperlipid archives from the beginning. I'm still only in 2009. :-)
I just finished the post which is an overview of "the dark side of ketosis." Peter's regular readers will be aware that he flirts with the borderline, but largely TRIES to stay OUT of it. And that, largely because Kwasniewski recommends it. The comment section was full of people agreeing AND disagreeing.
We're all genetically different, and have different starting-points when boarding the low-carb train! I've always thought it bizarre that some people find ketosis stressful (or at least describe it so), when it's the hugest reliever of physical discomfort that i've ever found!
One person thought that ketosis is fine for those with healthy adrenal function, but questionable for the less hardy. Peter observed that certain stress hormones are raised by entering ketosis, but diminish with time. Other people pointed out various difficulties that they or their friends have observed, only to have it pointed out that they were not natural results of VLC, but confounded by other behaviors or dietary factors.
Obviously, some of us thrive on ketosis, and some have more trouble with it. Some also adapt more slowly and with more difficulty, but end up feeling better if they persevere. I rather suspect that the raised cortisol, adrenaline, etc FEEL worse to people who aren't accustomed to the keyed-up energy that comes with things like ghrelin also. I get it with supplementing tyrosine or DLPA -- if i'm active that day, these supps (like caffeine) are a great boost. But if i sit down to read after taking them i get way too much mental agitation. Is it REALLY stress, or is it energy that we interpret AS stressful?
I don't know. I DO however take it with a grain of salt when some people (bread-lovers especially) call a moderate LC diet "stressful"....