History of the diet and its side effects
Perhaps one of the least discussed but most important of the changes in ketogenic diet research in the past decade has been the identification of its side effect profile. During the 1920s and 1930s, when the ketogenic diet was one of the most popular anticonvulsant therapies, side effects such as acidosis (low bicarbonate levels in the blood), constipation, and abnormal menstrual periods (in adult women) were discussed and were just starting to be investigated.
However, over the following 60 years, research into the ketogenic diet focused nearly exclusively on demonstrating that it worked in order to answer its critics, rather than researching side effects. All this has changed in the past decade, and now that the ketogenic diet is no longer perceived as an alternative treatment, as James Wheless, MD, titled his editorial in 2001, the ketogenic diet is a “medical therapy with side effects”, and researchers have agreed.(1) Although most of the side effects I will discuss are important to be observant for, and can be bothersome, it is rare to have to stop the diet because of them.