caused by changes in enzyme levels, especially in those enzymes involved in both fat and
carbohydrate burning (7). High levels of free fatty acid levels also affect glucose transport and
utilization (8).
Long periods of time without carbohydrate consumption leads to a down regulation in the
enzymes responsible for carbohydrate burning. Additionally, high levels of free fatty acids in the
bloodstream may impair glucose transport (8). This change occurs both in the liver (7) and in
the muscle (7,9). With carbohydrate refeeding, these changes are gone within 5 hours in the liver
and 24-48 hours in muscle tissue (10,11).
In practice, many individuals report what appears to be rebound hypoglycemia (low blood
sugar) either during the carb-up or during the first few days of eating carbohydrates when
ketogenic eating is ended, for the reasons discussed above.
Ketones themselves do not appear to alter how cells respond to insulin (6) which goes
against the popular belief that ketogenic diets somehow alter fat cells, making them more likely
to store fat when the ketogenic diet is resumed. Practical experience shows this to be true, as
many individuals have little trouble maintaining their bodyfat levels when the ketogenic diet is
stopped, especially if their activity patterns are maintained.
To reiterate, the key to maintenance of a new bodyweight/bodyfat level is to balance
energy consumption with energy expenditure. This makes exercise an absolute requirement for
weight/fat maintenance when a diet is abandoned.
Section 2: Recommendations for ending a SKD or TKD
There are few practical recommendations for ending a ketogenic diet in the literature. In
research studies of the protein sparing modified fast (PSMF), carbohydrates are typically
reintroduced slowly to minimize weight gain and gastric upset, which occurs in some people.
Ending a SKD or TKD can be done in one of two fashions. If an individual no longer wishes fat
loss, but chooses to stay on the SKD/TKD, fat intake can be increased (to raise calories to a
maintenance level of approximately 15-16 calories/pound) until fat loss stops.
If an individual wishes to stop the SKD/TKD altogether and de-establish ketosis, obviously
carbohydrates will have to be added to the daily diet. This has several important consequences.
First and foremost, as dietary carbohydrates are added to the diet, dietary fat must be reduced to
avoid the consumption of excess calories. Since fat contains approximately twice as many
calories per gram as carbohydrate (9 calories/gram vs. 4 calories/gram), for every 2 grams of
carbohydrate which are added to the diet, 1 gram of fat must be removed.
Individuals concerned with rapid weight regain when they end a ketogenic diet should
simply introduce carbohydrates slowly, perhaps adding twenty to thirty grams per day at most.
To avoid possible problems with rebound hypoglycemia, primarily vegetables should be consumed
with starches (pasta, rice, breads) remaining limited.
Many individuals who turn to ketogenic diets to lose bodyfat tend to have problems with
excessive carbohydrate consumption in the first place, finding that high- carbohydrate, very-low-
fat diets increase their hunger. By the same token, individuals coming off of a ketogenic diet
frequently find that their taste for starchy foods, especially high glycemic index carbs, has