Acute oral intake of beta-hydroxybutyrate in a pilot study transiently increased its capillary levels in healthy volunteers

A ketogenic diet refers to a dietary approach that promotes nutritional ketosis by restricting carbohydrates (usually to less than 50g per day) and increasing the intake of fat with adequate consumption of protein. With a shortage of available glucose, fat from dietary source or stored adipose deposits is metabolized into ketone bodies [acetoacetate, β-hydroxybutyrate (βHB) and acetone] that can be utilized by the cells for energy.1 Systematic reviews and meta-analyses have reported the effectiveness of ketogenic diets in treating intractable epilepsy in adults and children,2,3 preventing an increase in appetite on reduced calorie diets,4 and achieving longterm bodyweight reduction.5 Emerging studies have shown that ketogenic diets may help diabetes management and improve exercise performance.6,7 However, compliance with a ketogenic diet can be difficult, as many have perceived the diet to be rigid or experienced adverse effects such as gastrointestinal disturbances.8,9 It has also been reported anecdotally as well as in the literature10 that, when following ketogenic diets or very-low-calorie diets (VLCD), there is a short lag time in the increase in circulating ketone bodies in conditions of reduced glucose intake, during which individuals report symptoms described as ‘keto flu’, including light headedness, irritability, fatigue and hunger. Hence, there has been increased interest in utilizing additional methods to enhance compliance and to facilitate the induction and maintenance of ketosis.