to a CKD. Based on anecdotal reports, it seems that the adaptations do occur, but that they
simply take longer.
For example, most people starting any type of ketogenic diet go through a period of low
energy, where they are mentally ‘fuzzy’. Those who stay on a SKD generally move past this
stage by the second or third week of dieting. In contrast, those on a CKD seem to take slightly
longer to overcome this feeling. For example, this author experienced a great deal of fatigue in the
first week of being on a CKD, a smaller (but still above baseline) amount of fatigue during the
second week, and essentially no fatigue by the third week.
This anecdotal data suggests that the adaptation of the brain to ketosis may take slightly
longer due to the insertion of a carb-load phase. This also suggests that individuals may want to
do two weeks of an SKD prior to their first carb-up, to allow the adaptations to occur more
quickly. Of course, if this compromises training intensity, it is not a viable option.
Long term effects of a CKD
Although the myriad effects of ketogenic diets are discussed in detail in chapter 7, another
concern is what long term metabolic effects a CKD will have. There is unfortunately no answer.
It seems logical that any long-term adaptations to ketosis will be reversed when a non-ketogenic
diet is followed for a sufficient period of time but this is mere speculation.
Anecdotally, it appears that some of the adaptations to ketogenic diets continue even after
a non-ketogenic diet has been followed. The easiest one to examine is the aforementioned fatigue
and ‘mental fuzziness’ during the first week. In general, individuals (including this author)
returning to a CKD after a period of more ‘balanced’ dieting do not experience the same level of
fatigue as when they first started the diet. This seems to suggest that some of the changes in the
brain (especially with regards to ketone usage) may be longer lasting. Once again, the lack of long
term data prevents any conclusions from being drawn.
However, and this is repeated throughout the book, the lack of long term data on the CKD
(or any other ketogenic diet) is arguably the most compelling reason not to remain on it in the
long term. Simply put, the lack of data means that no long term safety can or should be implied.
The CKD, like any fat loss diet, should be used until the fat loss goal (whatever that may be) is
achieved and then discontinued in favor of a more ‘balanced’ diet. Strategies for ending a CKD
appear in chapter 14.
Section 4: Is the carb-load anabolic?
Several popular authors suggest that the carb-loading phase of a CKD is anabolic,
stimulating muscle growth (30,31). However there is little direct research on this topic and only
speculation can be offered. To understand the potential impact of the carb-load on muscle
growth, it is necessary to discuss anabolic and catabolic processes, as well as some of the
mechanisms regulating protein synthesis.