Development of an Athlete Diet Index for Rapid Dietary Assessment of Athletes

The association between diet and sleep with internalising symptoms in young athletes: a serial multiple mediation models

Introduction

Athletes frequently experience anxiety and depression at rates similar to or higher than non-athletes. A balanced diet can alleviate athletes internalizing symptoms. Moreover, diet and sleep are all associated with internalising symptoms. Our study investigates how sleep quality mediates the impact of dietary habits on internalizing symptoms in athletes.

Methods

The current cross-sectional study involved 758 Chinese young athletes. The adapted Australian Athletes Diet Index was used to assess dietary patterns, and sleep was measured using the Athletes Sleep Screening Questionnaire. The Generalised Anxiety Disorder 7 scale and the Patient Health Questionnaire 9-item scale were used to assess symptoms of anxiety and depression. Structural Equation Modelling (SEM) analysis was used to examine the mediating role of sleep quality in young athletes. Raw scores of chronotypes, sleep quality, anxiety and depression were calculated for the statistical analysis.

Results

No significant indirect effects were found in adolescents. In adult athletes, diet mediated the relationship between chronotype and sleep quality (β = -0.028, p  <  0.001). Sleep quality mediated the association between diet and anxiety (β = -0.060, p = 0.001), and depression (β = -0.076, p = 0.001). Additionally, diet and sleep quality mediated the association between chronotypes and anxiety (β = -0.028, p = 0.001), and depression (β = -0.028, p = 0.001).

Conclusion

Sleep quality mediated the relationship between dietary patterns and internalising symptoms in young adult athletes. Additionally, diet and sleep quality mediated the association between chronotypes and internalising symptoms in young adult athletes.

Practical Application and Methodological Considerations on the Basics of Sports Nutrition in Basketball: A Comprehensive Systematic Review of Observational and Interventional Studies

The current systematic review (PROSPERO registration no. CRD42022334707) of observational (OS) and interventional studies (IS) aimed at evaluating the state of scientific knowledge on the basics of sports nutrition, framing discipline-specific dietary recommendations, and indicating potential directions for future studies in various age, experience level, and able-bodied abilities groups of basketball players (BP). A systematic search of PubMed, SPORTDiscus, and Web of Science ended on 20 December 2022. Records were excluded if reporting studies on animals, sport disciplines other than basketball, or supplementation protocols other than those related to macronutrients and hydration manipulations. Risk of bias (RoB) was evaluated using Cochrane RoB_2 tools, 'JBI checklist for prevalence studies', and 'Quality assessment tool for before-after (pre-post) studies with no control group'. The relevant data was synthesized in tables and a narrative review was performed. Seventy-two records were included (2581 participants): 63 were on able-bodied BP (2433 participants) and 9 on para-athlete players (148 participants); 45 records were OS and 27 IS. The review disclosed widespread poor nutritional habits and knowledge and shortages in applying adequate nutritional and hydration practices in BP. Moreover, the systematic review revealed the lack of a sufficient number of investigations delivering reliable proof for framing discipline-specific and evidence-based recommendations on the basics of sports nutrition in basketball.

Development of an Instrument to Evaluate the Intake of Liquids, Food and Supplements in Endurance Competitions: Nutritional Intake Questionnaire for Endurance Competitions-NIQEC

BACKGROUND

In the last few years endurance sports have experienced a great increase in the number of competitions and participants. Dietary-nutritional planning is key for performing well during such competitions. To date, there is no questionnaire expressly developed to be able to analyze the consumption of liquids, foods, and supplements, as well as gastrointestinal problems in these events. This study describes the development of the Nutritional Intake Questionnaire for Endurance Competitions (NIQEC).

METHODS

The study was composed in the following phases: (1) Bibliographic search for the most important nutrients, (2) focus groups (17 dietitian-nutritionists and 15 experienced athletes) and generation of items, (3) Delphi surveys, and (4) cognitive interviews.

RESULTS

After an initial shaping of the questionnaire with the items that emerged in the focus groups, their relevance was evaluated by means of the Delphi survey, which showed more than 80% approval for most items. Finally, the cognitive interviews indicated that the questionnaire was simple and complete for its purpose. The final NIQEC (n = 50 items) was divided in 5 sections: Demographic data; sports data; consumption of liquids, food and supplements before, during, and after the competition; gastrointestinal complaints, and dietary-nutritional planning for the competition.

CONCLUSIONS

The NICEQ is a useful tool that allows collecting information from participants on sociodemographic factors and gastrointestinal complaints, and estimating the intake of liquid, food, and supplements, for endurance competitions.

Developing Nutrition Knowledge and Attitude Measures for Athletes With the Knowledge-Attitude-Behavior Model

Purpose: Nutrition education programmes are often created to improve dietary intake in athletes. Unfortunately, the inconsistent link between nutrition knowledge and dietary behavior suggests that nutrition knowledge may not be a key influencer of dietary behavior. The Knowledge-Attitude-Behavior (KAB) model has been used in nutrition education although studies that evaluated this model were largely compromised by poorly constructed instruments and methodological discrepancies. Method: To improve understanding of the model, a Nutrition Knowledge Questionnaire (NKQ) and Athlete's Perspective on Nutrition (APN) instrument was developed using the theory of planned behavior as its theoretical framework. Validity and reliability were examined for 193 Sports Science students and 11 elite netballers. Content and face validity of the 48-item NKQ was confirmed by expert sport dietitians. Discriminant validity of the NKQ and factorial validity of the APN was established. Both instruments demonstrated acceptable internal consistency and good test-retest reliability. The final instruments were administered to elite athletes in a pilot study to understand the KAB model. Results: Correlation between nutrition knowledge and dietary behavior was significant (r = .811, p = .01). Nutrition knowledge was a positive predictor of netballers' dietary behavior (β = .8, t(2) = 3.899, p = .005) but attitude was not (β = -.097, t(2) = -.471, p = .65). Conclusion: Two psychometrically sound instruments developed in this study can be used to measure nutrition knowledge and attitude in an Asian group of athletes. The pilot study with athletes showed that nutrition knowledge predicted dietary behavior.

A Proposed Conceptual Sport Nutrition Approach for Athlete Development and Assessment: The Athlete Nutrition Development Approach

Appropriate dietary intake can improve athletes' health and sport performance and is a direct result of eating behaviours. Therefore, assessing and shaping athletes' eating behaviours and dietary intake is critical to the provision of sport nutrition services. As such, nutrition practitioners must also consider the determinants of eating behaviours. However, dietary intake, eating behaviours, and its determinants are inconsistently defined in the literature, requiring nutrition practitioners to navigate a complicated landscape of concepts and terminology. This is further complicated by limitations in practically measuring and influencing eating behaviours and dietary intake. The proposed Athlete Nutrition Development Approach was developed to aid practitioners in servicing decisions through the athlete development process, through a three-tiered approach to sport nutrition service delivery. Tier 1 addresses the determinants of eating behaviours, Tier 2 directly addresses eating behaviours and dietary intake, and Tier 3 addresses the consequences of dietary intake in relation to health and sport performance. Each tier includes tools for assessment and development.

Fueling Gut Microbes: A Review of the Interaction between Diet, Exercise, and the Gut Microbiota in Athletes

The athlete's goal is to optimize their performance. Towards this end, nutrition has been used to improve the health of athletes' brains, bones, muscles, and cardiovascular system. However, recent research suggests that the gut and its resident microbiota may also play a role in athlete health and performance. Therefore, athletes should consider dietary strategies in the context of their potential effects on the gut microbiota, including the impact of sports-centric dietary strategies (e.g., protein supplements, carbohydrate loading) on the gut microbiota as well as the effects of gut-centric dietary strategies (e.g., probiotics, prebiotics) on performance. This review provides an overview of the interaction between diet, exercise, and the gut microbiota, focusing on dietary strategies that may impact both the gut microbiota and athletic performance. Current evidence suggests that the gut microbiota could, in theory, contribute to the effects of dietary intake on athletic performance by influencing microbial metabolite production, gastrointestinal physiology, and immune modulation. Common dietary strategies such as high protein and simple carbohydrate intake, low fiber intake, and food avoidance may adversely impact the gut microbiota and, in turn, performance. Conversely, intake of adequate dietary fiber, a variety of protein sources, and emphasis on unsaturated fats, especially omega-3 (ɷ-3) fatty acids, in addition to consumption of prebiotics, probiotics, and synbiotics, have shown promising results in optimizing athlete health and performance. Ultimately, while this is an emerging and promising area of research, more studies are needed that incorporate, control, and manipulate all 3 of these elements (i.e., diet, exercise, and gut microbiome) to provide recommendations for athletes on how to "fuel their microbes."

Sports Nutrition: Diets, Selection Factors, Recommendations

An athlete’s diet is influenced by external and internal factors that can reduce or exacerbate exercise-induced food intolerance/allergy symptoms. This review highlights many factors that influence food choices. However, it is important to remember that these food choices are dynamic, and their effectiveness varies with the time, location, and environmental factors in which the athlete chooses the food. Therefore, before training and competition, athletes should follow the recommendations of physicians and nutritionists. It is important to study and understand the nutritional strategies and trends that athletes use before and during training or competitions. This will identify future clinical trials that can be conducted to identify specific foods that athletes can consume to minimize negative symptoms associated with their consumption and optimize training outcomes.

Measuring the sports nutrition knowledge of elite Australian athletes using the Platform to Evaluate Athlete Knowledge of Sports Nutrition Questionnaire

AIMS

To evaluate the nutrition knowledge of elite Australian athletes, and to obtain feedback from sports dietitians on the Platform to Evaluate Athlete Knowledge of Sports Nutrition Questionnaires' (PEAKS-NQ) suitability.

METHODS

Sports dietitians from the National Institute Network across Australia recruited athletes to complete the online, 50-item PEAKS-NQ which contained two sections (General Nutrition and Sports Nutrition). Sports dietitians provided feedback on the PEAKS-NQ using a 14-item questionnaire (with two open-ended items). The main outcome measures were nutrition knowledge score and tool suitability (usefulness, acceptability and feasibility) scores. For knowledge scores, independent t-tests, ANOVA and Chi-square tests were used to evaluate differences between groups. Suitability was evaluated using descriptive statistics.

RESULTS

Twelve sports dietitians from the National Institute Network in Australia recruited a convenience sample of 240 athletes (21.3 ± 4.3 years, 63.5% female, 63.3% competed internationally). Athletes scored 70.7 ± 10.5%, with better general vs sports nutrition knowledge. Females had higher overall scores (P < .001) with no differences for age or sport played. University-educated athletes scored higher than non-tertiary educated athletes (P = .004). Knowledge gaps were identified in fats (role and food sources), recovery nutrition and managing body composition. Sports dietitians rated suitability of PEAKS-NQ positively with complete agreement on 8 of 12 items.

CONCLUSIONS

Athletes have greater understanding of general nutrition compared to sports nutrition concepts and may benefit from education on applying nutrition in sports-specific contexts. Sports dietitians' responses showed PEAKS-NQ was a highly acceptable, feasible and useful measure.

Development and validation of a questionnaire investigating endurance athletes practices to manage gastrointestinal symptoms around exercise

AIM

To develop and validate a questionnaire investigating endurance athletes' carbohydrate beliefs, knowledge, information sources, and other dietary and non-dietary practices related to exercise-associated gastrointestinal symptoms.

METHODS

A questionnaire was developed by a review of relevant literature and sports-related questionnaires, and input from five experienced sports dietitians. Item construct and format was adapted and modified from a previous questionnaire. The modified questionnaire sought information on demographics, nutrition knowledge, beliefs, intended practices, information sources and exercise-associated gastrointestinal symptoms. A five-phase validity process was conducted to determine content, face and construct validity, item difficulty and internal reliability of the questionnaire. The Delphi technique was applied with experts over three anonymous rounds. Items were reviewed to determine whether to keep, modify, or delete, rate the relevance of each item using a content validity index (CVI), and provide comments. A content analysis was conducted on all comments after each round. Online interviews were conducted with a pilot group of endurance athletes (n = 15) to assess item difficulty and feasibility. Nutrition knowledge was compared between pilot group of athletes and experts to determine construct validity and internal consistency. A test-retest process was applied to a second pilot group (n = 8) to verify questionnaire reliability.

RESULTS

High CVI (≥.83) and agreement scores were obtained through the Delphi technique. High reliability (r = .942) and acceptable internal consistency (α = .53-.78) of the questionnaire were obtained.

CONCLUSIONS

The questionnaire was shown to be a valid and reliable tool that will be of use for clinicians and research purposes.

Diet Quality of Elite Australian Athletes Evaluated Using the Athlete Diet Index

While athletes’ nutrient intakes have been widely reported, few studies have assessed the diet quality of athletes. This is the first study to evaluate the diet quality of athletes using the purpose-built Athlete Diet Index (ADI). A convenience sample of 165 elite athletes from Australian sporting institutions completed the ADI online, with subsequent automated results provided to their respective accredited sports dietitians (ASDs). At the completion of athlete participation, ASDs (n = 12) responded to a range of survey items using a Likert scale (i.e., 1 = strongly agree to 5 = strongly disagree) to determine the suitability of the ADI in practice. Differences in ADI scores for demographics and sport-specific variables were investigated using independent t-tests, analysis of variance (ANOVA) and Bonferroni multiple comparisons. Spearman’s rank correlation was used to assess the association between total scores and demographics. The mean total ADI score was 91.4 ± 12.2 (range 53–117, out of a possible 125). While there was no difference in total scores based on demographics or sport-specific variables; team sport athletes scored higher than individual sport athletes (92.7 vs. 88.5, p < 0.05). Athletes training fewer hours (i.e., 0–11 h/week) scored higher on Dietary Habits sub-scores compared with athletes training more hours (≥12 h/week; p < 0.05), suggesting that athletes who train longer may be at risk of a compromised dietary pattern or less than optimal nutrition practices that support training. Most (75%) ASDs surveyed strongly agreed with the perceived utility of the ADI for screening athletes and identifying areas for nutrition support, confirming its suitability for use in practice.

Relative validity and reliability of a novel diet quality assessment tool for athletes: the Athlete Diet Index

Diet quality indices are a practical, cost-effective method to evaluate dietary patterns, yet few have investigated diet quality in athletes. This study describes the relative validity and reliability of the recently developed Athlete Diet Index (ADI). Participants completed the electronic ADI on two occasions, 2 weeks apart, followed by a 4-d estimated food record (4-dFR). Relative validity was evaluated by directly comparing mean scores of the two administrations (mAdm) against scores derived from 4-dFR using Spearman's rank correlation coefficient and Bland-Altman (B-A) plots. Construct validity was investigated by comparing mAdm scores and 4-dFR-derived nutrient intakes using Spearman's coefficient and independent t test. Test-retest reliability was assessed using paired t test, intraclass correlation coefficients (ICC) and B-A plots. Sixty-eight elite athletes (18·8 (sd 4·2) years) from an Australian sporting institute completed the ADI on both occasions. Mean score was 84·1 (sd 15·2; range 42·5-114·0). The ADI had good reliability (ICC = 0·80, 95 % CI 0·69, 0·87; P < 0·001), and B-A plots (mean 1·9; level of agreement -17·8, 21·7) showed no indication of systematic bias (y = 4·57-0·03 × x) (95 % CI -0·2, 0·1; P = 0·70). Relative validity was evaluated in fifty athletes who completed all study phases. Comparison of mAdm scores with 4-dFR-derived scores was moderate (rs 0·69; P < 0·001) with no systematic bias between methods of measurement (y = 6·90-0·04 × x) (95 % CI -0·3, 0·2; P = 0·73). Higher scores were associated with higher absolute nutrient intake consistent with a healthy dietary pattern. The ADI is a reliable tool with moderate validity, demonstrating its potential for application to investigate the diet quality of athletes.