Yeah... I've seen some people come around asking about NK who are already low weight and such and I try to steer them clear.
Sure some people get the energy and clarity thing... but the biggest side effect for most of people is appetite suppression which is why it works for weight loss and for those with disordered eating.
For those people who are at a healthy weight and doing it for a medical reason like epilepsy they need to approach it more carefully and with caloric needs at the forefront, sometimes they have to ease into that level of eating slowly.
For the people like you who are a good body weight or just need to lose 10-20 lbs, and those really active, I always tell them do normal PB or higher carb/lower fat with plenty of veg, tubers, and fruits for a while first to see how that works...
HFLC and NK isn't for everyone.