Chapter 7:
Other effects of the ketogenic diet
The ketogenic diet has numerous metabolic effects, many of which are discussed in the
previous chapters. However there are numerous other metabolic effects that need to be
discussed as well as concerns which are typically raised regarding the ketogenic diet.
This chapter is a catch-all to discuss any effects on the body that have not been discussed
in previous chapters. It examines the effects (and side-effects) of the metabolic state of ketosis
on the human body. As well, some of the major health concerns which have been voiced regarding
the ketogenic diet are addressed here.
There are ultimately two main concerns regarding the ketogenic diet in terms of health
risks. The first is the potential negative effects of the ‘high protein’ intake of the ketogenic diet.
Additionally, there is the effect of high levels of ketones. They are discussed as needed below.
Please note that not all of the effects of ketosis on human physiology are known at this
time. Ketosis has been studied for almost 100 years and will most likely continue to be studied so
any information provided here represents only the current base of knowledge. For this discussion,
no distinction is made, except as necessary, between starvation ketosis and dietary ketosis.
A note on long-term effects
There are few studies of the long term effects of a ketogenic diet. One of the few, which
followed two explorers over a period of 1 year was done almost 70 years ago (1). Beyond that
study, the two models most often used to examine the effects of the ketogenic diet are the Inuit
and pediatric epilepsy patients. Epileptic children have been studied extensively, and are kept in
ketosis for periods up to three years. In this group, the major side effects of the ketogenic diet are
elevated blood lipids, constipation, water-soluble vitamin deficiency, increased incidence of kidney
stones, growth inhibition, and acidosis during illness.
However, the pediatric epilepsy diet is not identical the the typical ketogenic diet used by
dieters and healthy adults, especially in terms of protein intake, and may not provide a perfect
model. While studies of epileptic children give some insight into possible long term effects of a
ketogenic diet, it should be noted that there are no studies of the long-term effects of a CKD or
similar diet approach. The consequences of alternating between a ketogenic and non-ketogenic
metabolism are a total unknown. For this reason, it is not recommended that a CKD, or any
ketogenic diet, be followed indefinitely.
Insulin resistance
Although low-carbohydrate diets tend to normalize insulin and blood glucose levels in many
individuals, a little known effect is increased insulin resistance when carbohydrates are refed.
There is little research concerning the physiological effects of refeeding carbohydrates after long-