The impact of dieting culture is different between sexes in endurance athletes: a cross-sectional analysis

Australian elite sport coaches' mental health literacy of eating disorders, orthorexia, and muscle dysmorphia in athletes: A qualitative study

Athletes have an increased risk of developing eating disorders (EDs) compared to non-athletes. Coaches are in a unique position to identify symptoms and promote timely support; however, research has not yet explored coaches' mental health literacy about DSM-5 EDs and related orthorexia and muscle dysmorphia conditions in elite athletes. Eighteen Australian elite sport coaches from aesthetic, weight-class, and endurance sports participated in individual semi-structured interviews to investigate their mental health literacy of EDs and related conditions. Four themes emerged from the data. Theme 1 (knowledge of EDs and related conditions) highlighted coaches' awareness of maladaptive perfectionism as a key risk factor, limited awareness of EDs without observable weight loss, and conceptualisation of EDs as a nutritional issue. Theme 2 (facilitators to managing EDs) highlighted the helpfulness of building trust with athletes, accessing support staff, emphasising body functionality, and lived experience. Theme 3 (barriers to managing EDs) highlighted coaches' challenges with communicating about body image, responding to denial, and funding constraints. Theme 4 (future ED education and training) highlighted coaches' desire for in-person, interactive training and to support junior-level coaches. These findings may assist in developing tailored educational resources to improve coaches' ability to identify and manage eating-related concerns in athletes.

Ketogenic diets, exercise performance, and training adaptations

PURPOSE OF REVIEW

The ketogenic diet has been proposed as a nutritional strategy in sports. This review was undertaken to provide an overview of the recent literature concerning the effects of ketogenic diet on exercise performance and training adaptations.

RECENT FINDINGS

Most recent literature on the ketogenic diet and exercise performance showed no beneficial effects, especially for trained individuals. During a period of intensified training, performance was clearly impaired during the ketogenic intervention, while a diet with high carbohydrates maintained physical performance. The main effect of the ketogenic diet resides in metabolic flexibility, inducing the metabolism to oxidize more fat for ATP resynthesis regardless of submaximal exercise intensities.

SUMMARY

The ketogenic diet is not a reasonable nutritional strategy, as it has no advantage over normal/high carbohydrate-based diets on physical performance and training adaptations even when used only in a specific training/nutritional periodization stage.

Chronic and Postprandial Metabolic Responses to a Ketogenic Diet Compared to High-Carbohydrate and Habitual Diets in Trained Competitive Cyclists and Triathletes: A Randomized Crossover Trial

Extreme carbohydrate deficits during a ketogenic diet (KD) may result in metabolic adaptations reflective of low energy availability; however, the manifestation of these adaptations outside of exercise have yet to be elucidated in cyclists and triathletes. The purpose of this study is to investigate the chronic and postprandial metabolic responses to a KD compared to a high-carbohydrate diet (HCD) and habitual diet (HD) in trained competitive cyclists and triathletes. For this randomized crossover trial, six trained competitive cyclist and triathletes (F: 4, M: 2) followed an ad libitum KD and HCD for 14 d each after their HD. Fasting energy expenditure (EE), respiratory exchange ratio (RER), and fat and carbohydrate oxidation (FatOx and CarbOx, respectively) were collected during their HD and after 14 d on each randomly assigned KD and HCD. Postprandial measurements were collected on day 14 of each diet following the ingestion of a corresponding test meal. There were no significant differences in fasting EE, RER, FatOx, or CarbOx among diet conditions (all p > 0.050). Although postprandial RER and CarbOx were consistently lower following the KD meal, there were no differences in peak postprandial RER (p = 0.452), RER incremental area under the curve (iAUC; p = 0.416) postprandial FatOx (p = 0.122), peak FatOx (p = 0.381), or FatOx iAUC (p = 0.164) between the KD and HD meals. An ad libitum KD does not significantly alter chronic EE or substrate utilization compared to a HCD or HD; postprandial FatOx appears similar between a KD and HD; this is potentially due to the high metabolic flexibility of cyclists and triathletes and the metabolic adaptations made to habitual high-fat Western diets in practice. Cyclists and triathletes should consider these metabolic similarities prior to a KD given the potential health and performance impairments from severe carbohydrate restriction.