To say that the keto diet has become one of the most popular diets of recent years is a complete understatement. Case in point: There are more than one million searches on Google every month for the keto diet. It’s unique because the fad diet has captured the interest of people who want to lose weight — and there’s no shortage of reported success stories to be found.
On the ketogenic diet, carbohydrates are restricted and so cannot provide for all the metabolic needs of the body. Instead, fatty acids are used as the major source of fuel. These are used through fatty-acid oxidation in the cell's mitochondria (the energy-producing parts of the cell). Humans can convert some amino acids into glucose by a process called gluconeogenesis, but cannot do this by using fatty acids. Since amino acids are needed to make proteins, which are essential for growth and repair of body tissues, these cannot be used only to produce glucose. This could pose a problem for the brain, since it is normally fuelled solely by glucose, and most fatty acids do not cross the blood–brain barrier. However, the liver can use long-chain fatty acids to synthesise the three ketone bodies β-hydroxybutyrate, acetoacetate and acetone. These ketone bodies enter the brain and partially substitute for blood glucose as a source of energy.
Some studies have shown a positive connection between ketosis and lower levels of ketosis, but as Paoli et all conclude in their paper Beyond Weight Loss: a review of the therapeutic uses of very-low-carbohydrate (ketogenic) diets, there is persuasive, although not yet conclusive, clinical and physiological evidence that the ketogenic diet could be effective in reducing the severity and progression of acne and randomized clinical trials will be required to resolve the issue.
Otherwise in a nutshell ketosis can be defined as a “metabolic state that happens when you consume a very low carb, moderate protein, high fat diet (or fast for extended periods) that causes your body to switch from using glucose as it’s primary source of fuel, to running off ketones. Ketones themselves are produced when the body burns fat, and they’re primarily used as an alternative fuel source when glucose isn’t available.” (Keto Clarity)
There are a number of different causes of acne, and one may be related to diet and blood sugar. Eating a diet high in processed and refined carbohydrates can alter gut bacteria and cause more dramatic blood sugar fluctuations, both of which can have an influence on skin health. Therefore, by decreasing carb intake, it's not a surprise that a ketogenic diet could reduce some cases of acne.
The ketogenic diet is usually initiated in combination with the patient's existing anticonvulsant regimen, though patients may be weaned off anticonvulsants if the diet is successful. Some evidence of synergistic benefits is seen when the diet is combined with the vagus nerve stimulator or with the drug zonisamide, and that the diet may be less successful in children receiving phenobarbital.
A survey in 2005 of 88 paediatric neurologists in the US found that 36% regularly prescribed the diet after three or more drugs had failed, 24% occasionally prescribed the diet as a last resort, 24% had only prescribed the diet in a few rare cases, and 16% had never prescribed the diet. Several possible explanations exist for this gap between evidence and clinical practice. One major factor may be the lack of adequately trained dietitians who are needed to administer a ketogenic diet programme.