Induction of mild states of hyperketonemia may improve physical and cognitive performance. In this study, we determined the kinetic parameters, safety and tolerability of (R)-3-hydroxybutyl (R)-3-hydroxybutyrate, a ketone monoester administered in the form of a meal replacement drink to healthy human volunteers. Plasma levels of β-hydroxybutyrate and acetoacetate were elevated following administration of a single dose of the ketone monoester, whether at 140, 357, or 714 mg/kg body weight, while the intact ester was not detected. Maximum plasma levels of ketones were attained within 1–2 h, reaching 3.30 mM and 1.19 mM for β-hydroxybutyrate and acetoacetate, respectively, at the highest dose tested. The elimination half-life ranged from 0.8–3.1 h for β-hydroxybutyrate and 8–14 h for acetoacetate. The ketone monoester was also administered at 140, 357, and 714 mg/kg body weight, three times daily, over 5 days (equivalent to 0.42, 1.07, and 2.14 g/kg/d). The ketone ester was generally well-tolerated, although some gastrointestinal effects were reported, when large volumes of milk-based drink were consumed, at the highest ketone monoester dose. Together, these results suggest ingestion of (R)-3-hydroxybutyl (R)-3-hydroxybutyrate is a safe and simple method to elevate blood ketone levels, compared with the inconvenience of preparing and consuming a ketogenic diet.

Breath acetone is as good a predictor of ketosis as is urinary acetoacetate. Breath acetone analysis is noninvasive and can be performed frequently with minimal discomfort to patients. As an indicator of ketosis in epilepsy patients consuming a ketogenic diet, breath acetone may be useful for understanding the mechanism of the diet, elucidating the importance of ketosis in seizure protection, and ultimately, enhancing the efficacy of the diet by improving patient monitoring.

No abstract

The authors analyzed blood metabolites in nine children with epilepsy prior to starting the ketogenic diet (KD) and 3 to 4 weeks after KD therapy. Elevated beta-hydroxybutyrate and cortisol levels were observed in all children on the KD. Free fatty acids increased 2.2-fold on the KD, with significant elevations in most polyunsaturated fatty acids (PUFA; arachidonate increased 1.6- to 2.9-fold and docosahexaenoate increased 1.5- to 4.0-fold). The rise in total serum arachidonate correlated with improved seizure control. Elevated PUFA may represent a key anticonvulsant mechanism of the KD.

PROSPERO CRD42017055951.

A main characteristic of children perceived as picky eaters is their tendency to avoid certain foods or food groups. The goal of this narrative review is to provide an overview of published studies that have examined whether picky eating in childhood is in fact associated with measurable differences in food and/or nutrient intakes and growth. While picky eaters appear to consume less vegetables compared to non-picky eaters, no consistent differences were observed for the intakes of other food groups or the intakes of energy, macronutrients and dietary fiber. Although, in some studies, picky eaters had lower intakes of certain vitamins and minerals, the levels consumed generally exceeded the recommended values, suggesting nutritional requirements are being met. No consistent relationship between childhood picky eating and growth status was observed, although significant differences in body weight/growth between picky and non-picky eaters were most discernible in studies where multiple defining criteria were used to identify picky eating. The research area would benefit from the adoption of a uniform definition of picky eating. More longitudinal assessments are also required to understand the long-term impact of picky eating on nutritional status and growth.

No abstract

Sports beverages formulated with fructose and glucose composites enhance exogenous carbohydrate oxidation, gut comfort, and endurance performance, relative to single-saccharide formulations. However, a critical review of performance data is absent. We conducted a comprehensive literature review of the effect of fructose:glucose/maltodextrin (glucose or maltodextrin) composites versus glucose/maltodextrin on endurance performance. Mechanistic associations were drawn from effects on carbohydrate metabolism, gut, and other sensory responses. Overall, 14 studies contained estimates of 2.5-3.0-h endurance performance in men, mostly in cycling. Relative to isocaloric glucose/maltodextrin, the ingestion of 0.5-1.0:1-ratio fructose:glucose/maltodextrin beverages at 1.3-2.4 g carbohydrate·min(-1) produced small to moderate enhancements (1-9 %; 95 % confidence interval 0-19) in mean power. When 0.5:1-ratio composites were ingested at ≥1.7 g·min(-1), improvements were larger (4-9 %; 2-19) than at 1.4-1.6 g·min(-1) (1-3 %; 0-6). The effect sizes at higher ingestion rates were associated with increased exogenous carbohydrate oxidation rate, unilateral fluid absorption, and lower gastrointestinal distress, relative to control. Solutions containing a 0.7-1.0:1 fructose:glucose ratio were absorbed fastest; when ingested at 1.5-1.8 g·min(-1), a 0.8:1 fructose:glucose ratio conveyed the highest exogenous carbohydrate energy and endurance power compared with lower or higher fructose:glucose ratios. To conclude, ingesting 0.5-1.0:1-ratio fructose:glucose/maltodextrin beverages at 1.3-2.4 g·min(-1) likely benefits 2.5-3.0 h endurance power versus isocaloric single saccharide. Further ratio and dose-response research should determine if meaningful performance benefits of composites accrue with ingestion <1.3 g·min(-1), relative to higher doses. Effects should be established in competition, females, other food formats, and in heat-stress and ultra-endurance exercise where carbohydrate demands may differ from the current analysis.