Kinda true... unfortunately removing carbs altogether also removes a lot of micro-nutrient sources, so supplementation becomes a requirement.
Some parts of this thread just nails how important the diet is.
There are "risks" in a lot of things we take for granted. Such as simply the types of foods we eat, which over time have more drastic effects than simply attempting to go into Ketosis once in a while.
I am just one of THOUSANDS of people within fitness, that manipulate the almighty carb (smartly coupled with proper eating habits)...
at the tight time......
at the right goal position....to attempt to solicit a favorable bodily response, and as healthy as ever.
Believe me when I tell you I tried sand blasting calorie cycles and corresponding variable deficits, and manipulating fitness activities when I first tried to dip below 9% BF. I never had to manipulate carbohydrates above 9% BF. I could eat a healthy volume of carbohydrates (of any type, at any time, and even before bed

), and lose weight, as long as a deficit was present.
I tried 3 months, and got no where (make this explanation extremely short), but when I lowered carbohydrates (around 30 grams--and this level was determined by me, for an "educated reason", and one of them was "speed" in glucose depletion when considering fitness activities), and adjoined it with cyclic calorie ranges and deficits, the game played became completely different, and I dropped the body fat I wanted, and it simply worked (again over simplifying what I did).
I react strong to a manipulation of carbohydrates. I also get rather strong symptoms, but I handle them
cause' I tough like dat', and want my goal, and know its a "temporary condition".
Drinking plenty of water and taking vitamins are of course on "my personal diet" menu when attempting to go into ketosis.
I generally mess around with the normal numbers needed (for a atypical day), and then add in a base frame of what is expended in weight training (understand there are many variables involved, and its an "approximate figure"), and come up with an "over-all need approximate total for carbs".
This can give a "general idea" how I expend them without training but through normal biological function, and expend them with training along side normal functioning expenditure.
Add in approximate glucose storage calories, the target carb line (say 50g) per day, and I can fairly deduce (for myself) when the glucose bucket "should approximately" empty, which would tell me (at least in personal numbers) how close I should be in entering ketosis (over simplifying version). If its wrong, I tweak something, eh?
I agree if one is in the correct goal position, one should eat at the higher carb number IF this will net the person fat loss that was troublesome before (not water loss).
When lowering carbs, and one may not even have to attempt to go into Ketosis. The higher number should be tried. If not, lower it some more, and keep tweaking (and tweaking the "types" of carbs, and this assumes deficit dieting and manipulating exercises didn't work, and other like attempts exhausted).
These 20g, 30g, 40g, and 50g, of carbs float around a lot. For some this could be the carb operating range to enter ketosis (dependent on factors such as training volume, such as how many sets and reps, intensity, and frequency of training, etc). But for others, it can be higher, it simply can depend on personal surrounding factors and simply their personal biological processes.
One has to read, and get educated.
Some attempt to do a Keto "type" diet (and there are many variants out there), without really understanding the "process" of the diet, and when things don't workout as planned, they do not know what to do, or what to manipulate to make a change; get frustrated, and motivation dies.
Manipulate the numbers and see what happens. I like my carbs (except when I am lowering them

). If it means I can eat 100g and meet ketosis, its just common sense to eat at that range, if it works for the person. If one thinks about it, the right person "could" enter Ketosis with 100g, if the volume, intensity, and frequency, of training
"was enough", and considering nature of employment, and the biological base needs in the equation.
ROCK ON ALL!
Best wishes
Chillen