BACKGROUND: Crossover studies can induce order effects, especially when they lack a washout period.
OBJECTIVE: We performed secondary analyses comparing groups of subjects randomly assigned to different diet orders in 2 inpatient crossover studies originally designed to compare within-subject differences in ad libitum energy intake. One study compared minimally processed low-carbohydrate (LC) compared with low-fat (LF) diets, and the other matched macronutrients and compared minimally processed food (MPF) with ultraprocessed food (UPF) diets.
METHODS: Diet order group comparisons of changes in body weight and body composition, and differences in energy expenditure and food intake were assessed over 4 wk in 20 adults randomly assigned to either the LC followed immediately by the LF diet (LC → LF) or the opposite order (LF → LC), and 20 adults randomly assigned to either the MPF followed by the UPF (MPF → UPF) diets or the opposite order (UPF → MPF).
RESULTS: Subjects randomly assigned to LC → LF lost 2.9 ± 1.1 kg more body weight (P <0.001) and 1.5 ± 0.6 kg more body fat (P = 0.03) than the LF → LC group, likely because the LC → LF group consumed 921 ± 304 kcal/d less than the LF → LC group (P = 0.003). These energy intake differences were driven by the last 2 wk (-1610 ± 312 kcal/d; P < 0.0001), perhaps because of carryover effects of gut adaptations during the first 2 wk arising from large differences in the mass of food (1296 ± 215 g/d; P <0.00001) and fiber consumed (58 ± 6 g/d; P <0.00001). There were no significant diet order effects on energy intake, body weight, or body composition changes between UPF → MPF and MPF → UPF groups.
CONCLUSIONS: Diet order significantly affected energy intake, body weight, and body fat in a 4-wk crossover inpatient diet study varying in macronutrients, but not in a similarly structured study varying in ultraprocessed foods. This trial was registered at clinicaltrials.gov as NCT03407053 and NCT03878108.

The disruption of brain energy metabolism, leading to alterations in synaptic signaling, neural circuitry, and neuroplasticity, has been implicated in severe mental illnesses such as schizophrenia, bipolar disorder, and major depressive disorder. The therapeutic potential of ketogenic interventions in these disorders suggests a link between metabolic disturbances and disease pathology; however, the precise mechanisms underlying these metabolic disturbances, and the therapeutic effects of metabolic ketogenic therapy, remain poorly understood. In this study, we conducted an in silico analysis of transcriptomic data to investigate perturbations in metabolic pathways in the brain across severe mental illnesses via gene expression profiling. We also examined dysregulation of the same pathways in rodent or cell culture models of ketosis, comparing these expression profiles to those observed in the disease states. Our analysis revealed significant perturbations across all metabolic pathways, with the greatest perturbations in glycolysis, the tricarboxylic acid (TCA) cycle, and the electron transport chain (ETC) across all three disorders. Additionally, we observed some discordant gene expression patterns between disease states and ketogenic intervention studies, suggesting a potential role for ketone bodies in modulating pathogenic metabolic changes. Our findings highlight the importance of understanding metabolic dysregulation in severe mental illnesses and the potential therapeutic benefits of ketogenic interventions in restoring metabolic homeostasis. This study provides insights into the complex relationship between metabolism and neuropsychiatric disorders and lays the foundation for further experimental investigations aimed at appreciating the implications of the present transcriptomic findings as well as developing targeted therapeutic strategies.

Restricted sugar and ketogenic diets can alter energy balance/metabolism, but decreased energy intake may be compensated by reduced expenditure. In healthy adults, randomization to restricting free sugars or overall carbohydrates (ketogenic diet) for 12 weeks reduces fat mass without changing energy expenditure versus control. Free-sugar restriction minimally affects metabolism or gut microbiome but decreases low-density lipoprotein cholesterol (LDL-C). In contrast, a ketogenic diet decreases glucose tolerance, increases skeletal muscle PDK4, and reduces AMPK and GLUT4 levels. By week 4, the ketogenic diet reduces fasting glucose and increases apolipoprotein B, C-reactive protein, and postprandial glycerol concentrations. However, despite sustained ketosis, these effects are no longer apparent by week 12, when gut microbial beta diversity is altered, possibly reflective of longer-term adjustments to the ketogenic diet and/or energy balance. These data demonstrate that restricting free sugars or overall carbohydrates reduces energy intake without altering physical activity, but with divergent effects on glucose tolerance, lipoprotein profiles, and gut microbiome.

BACKGROUND: Approximately one-third of US young adults (18-25 years) have obesity, and there are calls to help young adults lose weight to prevent weight-related chronic conditions. This pilot trial tested the feasibility and acceptability of a very low-carbohydrate (VLC) eating pattern, with supportive positive affect and mindful eating skills, for weight management among young females with obesity.
METHODS: In a single-arm trial, women (N = 17), aged 19-23, with obesity participated in a 4-month diet and lifestyle intervention. Participants were taught how to follow a VLC eating pattern with the help of a coach and 16 weekly web-based sessions. We assessed feasibility and acceptability through session participation, outcome collection, intervention satisfaction, and adverse events.
RESULTS: Seventeen participants enrolled and 14 (82%) reported body weight at 4 months. Fifteen participants (94% of those beginning the intervention) viewed at least one session, and 8/15 (53%) of these participants were active in the intervention, viewing at least half of the sessions. Among the nine participants who provided 4-month self-report information, intervention satisfaction was high (mean 5.89/7, 95% CI 4.59 to 7.19). Among participants with a 4-month body weight, 7/14 (50%) lost ≥ 5% of their body weight, and of those who were also active in the intervention, 6/7 (86%) lost ≥ 5% of their body weight. There were no serious adverse events.
CONCLUSIONS: The results of this pilot study suggest that a VLC eating pattern may be a feasible and acceptable approach for weight loss in some young women with obesity.
BACKGROUND: This trial was registered with ClinicalTrials.gov on August 18, 2021. The trial number is NCT05010083.

Ketogenic diets (KDs) have shown therapeutic potential for a range of neuropsychiatric disorders; however, there is insufficient data regarding the behavioral impacts of KDs in healthy populations. Here, we examined the impact of a KD on sexual behavior in young adult male Sprague-Dawley rats maintained on either a KD or standard chow diet (SD). We found that KD males exhibited higher mount rates, higher intromission rates (third and fourth tests only), and lower ejaculation likelihood (second test only) compared to SD males. Consequently, it may be that experience-dependent changes in the processing of sexual stimuli are not occurring as efficiently in KD males, thereby yielding the observed copulatory sequence alterations.

The effect of dietary macronutrients on fasting and postprandial responses was examined. Thirty-six healthy dogs were fed a high-carbohydrate (HiCHO) food once daily for 5 weeks, followed by randomization to either a high-protein, low-carbohydrate (PROT_LoCHO) or high-fat, low-carbohydrate (FAT_LoCHO) food for 5 weeks, then crossed over to the other LoCHO food for 5 weeks. Plasma samples were obtained at the end of each feeding period at timepoints before (0 h) and 2 h post-feeding. Apparent total circulating energy availability was assessed as a summation of the energetic contributions of measured glucose, β-hydroxybutyrate, triglycerides (TGs), non-esterified fatty acids (NEFAs), and fatty acids not from TGs or NEFAs. In both the fed and fasted states, there were increases in circulating apparent total energy availability after feeding the FAT_LoCHO food compared with the HiCHO or PROT_LoCHO foods. Changes from the postabsorptive to postprandial points in catabolic, anabolic, and signaling lipids all exhibited food effects. Consumption of either LoCHO food led to lower leptin/ghrelin ratios in the fasted state relative to the HiCHO food. The FAT_LoCHO food led to the highest postprandial levels of the incretins gastric inhibitory peptide and glucagon-like peptide-1, yet the lowest increases in insulin relative to the other foods. These findings provide information on how macronutrients can influence dietary energy processing and metabolic health.

OBJECTIVE: Considering the high prevalence of obesity and related metabolic impairments in the population, the unique role nutrition has in weight loss, reversing metabolic disorders, and maintaining health cannot be overstated. Normal weight and well-being are compatible with varying dietary patterns, but for the last half century there has been a strong emphasis on low-fat, low-saturated fat, high-carbohydrate based approaches. Whereas low-fat dietary patterns can be effective for a subset of individuals, we now have a population where the vast majority of adults have excess adiposity and some degree of metabolic impairment. We are also entering a new era with greater access to bariatric surgery and approval of anti-obesity medications (glucagon-like peptide-1 analogues) that produce substantial weight loss for many people, but there are concerns about disproportionate loss of lean mass and nutritional deficiencies.
RESULTS: No matter the approach used to achieve major weight loss, careful attention to nutritional considerations is necessary. Here, we examine the recent findings regarding the importance of adequate protein to maintain lean mass, the rationale and evidence supporting low-carbohydrate and ketogenic dietary patterns, and the potential benefits of including exercise training in the context of major weight loss. While losing and sustaining weight loss has proven challenging, we are optimistic that application of emerging nutrition science, particularly personalized well-formulated low-carbohydrate dietary patterns that contain adequate protein (1.2 to 2.0 g per kilogram reference weight) and achieve the beneficial metabolic state of euketonemia (circulating ketones 0.5 to 5 mM), is a promising path for many individuals with excess adiposity.

This study aimed to describe the frequency of dieting practices among adolescents and young adults in Canada, as well as determine the association between dieting and eating disorder attitudes and behaviors. Data from 2762 Canadian adolescents and young adults from the Canadian Study of Adolescent Health Behaviors were analyzed. Frequencies were used to determine the prevalence of 11 different diets among the sample, and chi-square tests were used to assess gender differences. Multiple modified Poisson and linear regression analyses were conducted to determine the associations between any dieting and eating disorder attitudes and behaviors. Among the sample, 15.7 % of girls and women, 10.4 % of boys and men, and 13.0 % of transgender/gender expansive (TGE) participants reported any dieting in the past 12 months, with the Ketogenic diet being most common among all genders. Results from regression analyses showed that engaging in any dieting in the past 12 months was associated with greater eating disorder psychopathology among girls, women, boys, and men, but not TGE participants. There were varying trends in association between specific types of dieting practices and eating disorder behaviors among girls, women, boys, and men. Dieting is relatively common among a national sample of Canadian adolescents and young adults, and engagement is associated with greater eating disorder psychopathology and behaviors. Healthcare and public health professionals should consider screening for eating disorders among adolescents and young adults who report engaging in dieting practices.

This article presents a hypothesis explaining the cause of migraines, suggesting that electrolyte imbalance, specifically a lack of sufficient sodium in the extracellular space of sensory neurons, leads to failed action potentials. The author argues that migraines are triggered when sodium channels fail to initiate action potentials, preventing communication between neurons. The article discusses the evolutionary perspective of the migraine brain, stating that migraineurs have a hypersensitive brain with more sensory neuronal connections, making them more reactive to environmental stimuli and in need of more minerals for the increased sensory neuronal communication. Since glucose is often used to reduce serum hypernatremia, it follows that a high carbohydrate diet reduces sodium availability for use in the brain, causing an electrolyte imbalance. Low carbohydrate diets, such as ketogenic, low carb-high fat (LCHF), and carnivore (all animal products), can be beneficial for migraineurs by reducing/eliminating carbohydrate intake, thereby increasing sodium availability. In support, many research papers and some anecdotal evidences are referred to. The article concludes by proposing lifestyle modifications, such as dietary changes and sodium intake management. These will provide migraineurs with a long-term healthy metabolic foundation helping them to maintain strong nutritional adherence and with that aiding continued proper neuronal functioning and migraine free life.

BACKGROUND: In 2009, the International Ketogenic Diet Study Group published recommendations for children receiving ketogenic diet (KD) therapy for epilepsy. The document included a table listing epilepsy syndromes and conditions in which the KD has been particularly beneficial, hoping that physicians would refer children for the KD sooner.
OBJECTIVE: To measure the impact of these 2009 recommendations on referral practice, we compared children initiated on the KD at Johns Hopkins Hospital (JHH) 10 years before and after the recommendations.
RESULTS: Overall, children referred to the KD who met indications increased from the pre- to post-recommendation group, 44 % (112/256) to 69 % (175/255) (p < 0.001), with JHH neurologists specifically referring more frequently (10/112, 9 % to 58/175, 33 %) (p < 0.01). Referrals increased for Glut-1 deficiency (0 % to 2.4 %, p = 0.015), Dravet syndrome (0 % to 6.7 %, p < 0.01), Rett syndrome (0.4 % to 3 %, p = 0.018), and formula-fed only status (16 % to 31 %, p < 0.01). The chances of > 50 % seizure reduction for all children referred improved slightly between decades (56 % to 61 %, p = 0.30).
CONCLUSIONS: Following the 2009 recommendations, our study shows there was an increase in referrals for children with indications at our center. Referrals from neurologists at our own institution increased the most. Ketogenic diet efficacy improved slightly over time but did not reach significance.