Dietary Intakes of Professional and Semi-Professional Team Sport Athletes Do Not Meet Sport Nutrition Recommendations: A Systematic Literature Review

ackground: to develop sport-speci c and e ective dietary advice, it is important to understand the dietary intakes of team sport athletes. This systematic literature review aims to (1) assess the dietary intakes of professional and semi-professional team sport athletes and (2) to identify priority areas for dietetic intervention. Methods: an extensive search of MEDLINE, Sports DISCUS, CINAHL, Web of Science, and Scopus databases in April–May 2018 was conducted and identi ed 646 studies. Included studies recruited team sport, competitive (i.e., professional or semi-professional) athletes over the age of 18 years. An assessment of dietary intake in studies was required and due to the variability of data (i.e., nutrient and food group data) a meta-analysis was not undertaken. Two independent authors extracted data using a standardised process. Results:21 (n=511) studies that assessed dietary intake of team sport athletes met the inclusion criteria. Most reported that professional and semi-professional athletes' dietary intakes met or exceeded recommendations during training and competition for protein and/or fat, but not energy and carbohydrate. Limitations in articles include small sample sizes, heterogeneity of data and existence of underreporting. Conclusions: this review highlights the need for sport-speci c dietary recommendations that focus on energy and carbohydrate intake. Further exploration of factors in uencing athletes' dietary intakes including why athletes' dietary intakes do not meet energy and/or carbohydrate recommendations is required. Keywords:sports nutrition; carbohydrate intake; energy; nutritional recommendations 1. Introduction 1.1. Nutrition for Team Sport Athletes Team sports can be de ned as

highlights the need for sport-speci c dietary recommendations that focus on energy and carbohydrate intake. Further exploration of factors in uencing athletes' dietary intakes including why athletes' dietary intakes do not meet energy and/or carbohydrate recommendations is required. Keywords:sports nutrition; carbohydrate intake; energy; nutritional recommendations 1. Introduction 1.1. Nutrition for Team Sport Athletes Team sports can be de ned as eld- and court-based sports with intermittent and high-intensity game patterns [1]. Match patterns will vary markedly among di erent sports and for speci c positions within a sport. Team sports are divided into three categories: (1) endurance-based sports including football (i.e., soccer), Australian football, hockey (2) strength and power sports such as rugby union and league, American football and (3) batting sports such as baseball, softball and cricket [1]. Athletes participating in professional team sports are supported by high-performance and medical sta , which aim to monitor and optimise tness, body composition and performance outcomes. The physiological demands of team sports di er and can include a range of performance modes including: running moderate to long distances, high intensity bouts of movement, variable activity patterns and small bouts Nutrients2019,11, 1160; doi:10.3390 /nu11051160 /journal/nutrients

Nutrients2019,11, 1160 2 of 16 of rest periods [1–3]. The variable nature of team sport exercise requires use both anaerobic and aerobic systems to fuel performance [1]. Therefore, each team sport and position within the sport, depending on the nature of training and competition, will have unique energy demands and nutrient requirements. To optimise performance and enhance recovery, international sporting committees (i.e., International Olympic Committee (IOC), American College of Sports Medicine (ACSM), International Society of Sports Nutrition (ISSN)) have provided nutrition recommendations to support dietitians working with athletes to meet their individual nutrition needs [4–9]. Dietitians must consider a range of sport-speci c factors including the rules, arena size, timing of competition, frequency of matches and length of seasons (including macrocycles: preseason, competition season, o -season) when assessing an athlete's nutrition requirements and goals. Additionally, the physique characteristics and position-speci c tasks of the sport will further in uence the nutritional requirements of athletes. For example, the sport of rugby union will require forwards to be heavier and stronger in comparison to backs who need to be leaner and faster [10]. Due to the sport-speci c factors, physique and position di erences, dietary advice for team sport athletes should be individualised. Recommendations that support athletes to consume su cient energy and the correct balance of macronutrients and micronutrients, with appropriate timing to enhance performance and recovery, will enable athletes to train and perform optimally [11]. An earlier review by Holway and Spriet [1] found that athletes competing in team sports commonly do not meet recommended dietary intake needs [1,12]. Those that fail to consume energy and/or maintain a diet that encompasses the appropriate balance of macronutrients may nd that this impedes on training adaptations and recovery [11,12]. De ciencies in energy can have implications for an athlete's performance including a loss of fat free mass, disturbances to immune function, decreased bone mineral density, increased susceptibility to injury and increased prevalence of symptoms of overtraining [11]. 1.2. Objectives In the past decade, thousands of new research papers have been published in sports nutrition and 17 new consensus statements and recommendation papers

energy can have implications for an athlete's performance including a loss of fat free mass, disturbances to immune function, decreased bone mineral density, increased susceptibility to injury and increased prevalence of symptoms of overtraining [11]. 1.2. Objectives In the past decade, thousands of new research papers have been published in sports nutrition and 17 new consensus statements and recommendation papers have been released by authoritative organisations such as the IOC, ACSM, ISSN [4–9,11,13–22]. There have also been a large number of published studies on the dietary intake of professional and semi-professional team sport athletes during this time [2,3,10,23–39]. With new sports nutrition recommendations [5–8,11,13–21] and updated literature reporting the dietary intake of team sport athletes, it is now timely to review the literature to determine whether team sport athletes consume diets that align with the sports nutrition recommendations [2,3,10,23–39]. This paper aims to review the literature on dietary intakes of professional and semi-professional team sport athletes systematically with the aim of identifying priority areas for dietetic intervention. 2. Materials and Methods 2.1. Protocol Registration All methods and search strategies were aligned with Preferred Reporting Items for Systematic Review (PRISMA) guidelines. This review was registered with International Prospective Register of Systematic Reviews (registration number: CRD42018105168) [40,41]. A PICOS criteria (i.e., Participants, Intervention, Comparison, Outcome and Study design) for review is de ned in Table. A systematic search using terms such as sport or team sport or dietary intake or food intake was conducted by one researcher (SJ). All keywords used in search are listed in Table.

Nutrients2019,11, 1160 3 of 16 Table 1. Participants, Intervention, Comparison, Outcome and Study (PICOS) criteria for inclusion and exclusion of studies. Parameter Description Population Professional and semi-professional team sport athletes Intervention OR exposure Baseline dietary intake Comparison Dietary intake in comparison to sports nutrition guidelines and recommendations. Outcomes Meeting /not meeting sports nutrition guidelines and recommendations Study design RCT (where baseline dietary intake data available), cross-sectional, longitudinal, thesis (unpublished and published) Abbreviations: RCT Randomised Control Trial. Table 2.Table of keywords. Concept Keywords Sport OR team sport “sport*” OR “team sport*” OR “football” OR “soccer” OR “football” OR “netball” OR “AFL” OR “Aussie rules” OR “rugby” OR “basketball” OR “grid iron” OR “American football” OR “hockey” Dietary intake OR food intake “nutrient requirement*” OR “dietary intake” OR “daily food intake” OR “food intake” 2.2. Search Strategy Five electronic databases including MEDLINE (Medlars International Literature Online), Sports DISCUS, CINAHL (Cumulative Index of Nursing and Allied Health Literature), Web of Science (WOS), and Scopus (World's largest abstract and citation database of peer-reviewed literature) were searched to investigate the dietary intake of professional and semi-professional team sport athletes by one researcher (SJ). The timeframe designated for the search included studies published from 2011 to present (i.e., after the 2011 review by Holway and Spriet) [1]. An additional limit regarding age (i.e.,>18 years) was included to limit results to adult athletes only. In order to identify any further relevant publications, the reference lists of the studies included were hand searched and other manual searches were conducted (i.e., Google Scholar). 2.3. Eligibility Criteria All original research (i.e., cross-sectional, longitudinal, published and unpublished thesis) conducted in adult team sport athletes (i.e., 18 years and older) and published since 2011 was considered for inclusion (Table). Randomised control trials were additionally included in the review if baseline dietary intake data was available. Randomised control trials where only post intervention dietary intakes were available, conference posters, abstracts and web-based articles were not included for review. Only professional and semi-professional athletes were included in the review; amateur and recreational athletes were not included. Only English-language studies were included for this review.

were additionally included in the review if baseline dietary intake data was available. Randomised control trials where only post intervention dietary intakes were available, conference posters, abstracts and web-based articles were not included for review. Only professional and semi-professional athletes were included in the review; amateur and recreational athletes were not included. Only English-language studies were included for this review. Included studies were required to provide baseline or habitual dietary intake data that quanti ed energy, macronutrients and micronutrients to allow for the speci ed conversions made and displayed in the data extraction table i.e., energy (MJ/day), carbohydrate (grams (g) and g kg 1 day 1 ), protein (g and g kg 1 day 1 ), fat (g and % total energy), calcium (mg/day) and iron (mg/day). Studies that reported dietary habits, dietary knowledge, attitudes, and education strategies where dietary intake was not quanti ed, were excluded from the review.

Nutrients2019,11, 1160 4 of 16 Table 3.Eligibility criteria. Inclusion Exclusion 1. Studies that include only team sport athletes. 1. Studies that include only individual athletes or sports. 2. Studies published since 2012. 2. Studies published up to 2011. 3. Studies that include only professional or semi-professional team sport athletes. 3. Studies that include only non-professional or amateur team sport athletes. 4. Studies that include only adult team sport athletes (i.e.,>18 years of age). 4. Studies that include adolescent and child team sports athletes (i.e.,<18 years of age). 5. English language studies. 5. Non-English language studies. 6. Studies that include quantitative measures of dietary intake that can be converted into units of intake per day for each nutrient. 6. Studies that include nutrition habits, attitudes, educational strategies, knowledge, where dietary intakes cannot be compared. 7. Studies that include the dietary assessment of total energy carbohydrate, protein fat, micronutrient intake (i.e., iron (mg/day), calcium (mg/day), folate etc.). 7. Studies where only supplement or antioxidant intake is assessed. 8. Studies that assess dietary intake using a validated method of assessment (i.e., 7 day food diary, 7 day weighed food diary, food records, 3 day food diaries, FFQ, diet histories etc.) and therefore estimates absolute dietary intake. 8. Studies that assess dietary intake, however methods used provide dietary assessments represented in food groups, percentage of total energy etc. 9. Only human studies that include; RCT (where baseline dietary intake data available), cross-sectional, longitudinal, thesis. 9. No animal studies, RCT (where only post intervention dietary intakes available), conference posters, reviews, abstracts and web-based articles. 10. Published and unpublished research (i.e., thesis). Abbreviations: FFQ Food Frequency Questionnaire, RCT Randomised Control Trial. 2.4. Study Selection All studies were screened based on title and abstract by main author (SJ). Articles deemed eligible for full text review were screened against inclusion and exclusion criteria (Table) by two authors (SJ and GB). Additional reviewers (AF and RB) provided advice on eligibility if a decision for inclusion and exclusion required feedback. Selection of included studies and reasons for exclusion are reported in Chart. Chart 1.Study section process.

(SJ). Articles deemed eligible for full text review were screened against inclusion and exclusion criteria (Table) by two authors (SJ and GB). Additional reviewers (AF and RB) provided advice on eligibility if a decision for inclusion and exclusion required feedback. Selection of included studies and reasons for exclusion are reported in Chart. Chart 1.Study section process.

Nutrients2019,11, 1160 5 of 16 2.5. Data Collection Process Dietary intake data were extracted from the included studies by two authors (SJ and GB). Data presented in Table (total mass (kg), body fat (%), fat free mass (kg)) and athletic level (professional or semi-professional)); details regarding the study background and methods; country of origin and survey method (i.e., 7-day food diary) and dietary intake results including total energy/calories (i.e., MJ), carbohydrate intake (i.e., g and g kg 1 day 1 ), protein intake (i.e., g and g kg 1 day 1 ), fat intake (i.e., g and % total energy), calcium intake (i.e., mg) and iron intake (mg). Where total energy intake was reported in calories, this was converted to MJ to enable comparison across studies. 2.6. Study Quality: Risk of Bias The quality of studies was examined by two authors (SJ and GB) using the Academy of Nutrition and Dietetics Quality Criteria Checklist from the Academy of Nutrition and Dietetics Evidence Analysis Manual [42]. The quality criteria checklist provides an assessment based on relevance and validity criteria questions, ranking studies as either positive, neutral or negative. A third reviewer (AF) reviewed any discrepancies that occurred during the quality analysis. Studies with positive ratings needed to describe study selection adequately (including inclusion and exclusion criteria), methods of comparing groups and the study setting, and include measurements that were valid and reliable. 3. Results 3.1. Study Selection The original search retrieved 646 studies that t the search criteria with an additional 15 studies identi ed by hand searches (Chart). After duplicates were removed, a title and abstract exclusion was undertaken and 45 studies were retained for full text assessment. After completion of full text assessment 21 studies were included in this review for data extraction, quality assessment and analysis. All studies included in the review had a positive or neutral quality rating [41]. 3.2. Study Characteristics The majority of studies included in this review included team sport athletes competing professionally and semi-professionally in Australia (n=255) [3,25,26,33,43] and Spain (n=81) [28–30,36], with the remaining studies including athletes from Europe (not-speci ed) (n=34)

review for data extraction, quality assessment and analysis. All studies included in the review had a positive or neutral quality rating [41]. 3.2. Study Characteristics The majority of studies included in this review included team sport athletes competing professionally and semi-professionally in Australia (n=255) [3,25,26,33,43] and Spain (n=81) [28–30,36], with the remaining studies including athletes from Europe (not-speci ed) (n=34) [10,27], England (n=30) [23,34], America (n=26) [32,38], Canada (n=25) [39], Brazil (n=19) [37], Netherlands (n=14) [24], South Africa (n=11) [35], United Kingdom (n=10) [2], and Mexico (n=6) [31,37]. The majority of studies included in this review reported the dietary intakes of professional team sport athletes [2,3,10,23,24,26–29,31,33,34,36,37], with additional studies exploring dietary intake of semi-professional team sport athletes [32,35,38,39] and studies exploring the dietary intakes of a combination of sports [25,30,43]. Studies included a range of team sport athletes with the majority of studies reporting on the dietary intakes of football athletes (n=210) [23–25,28,30,31,34,37], followed by Australian football (n=139) [3,26,43]. Across the remaining studies, other team sport athletes represented in this review include; rugby union (n=70) [10,27,33,35], ice-hockey (n=25) [39], wheelchair basketball (n=17) [29], American football (n=15) [32], handball (n=14) [36], volleyball (n=11) [38], rugby league (n=10) [2]. The majority of studies included in this review used a cross-sectional study design (n=14), with the remaining studies using pre-post-test [32,38], case-study [27,29], case control [30] andlongitudinal [ designs to assess dietary intake. Dietary intake data were collected most frequently using food diaries/records (weighed and not weighed). Studies used 7-day food diaries [2,3,23,28,33,35,39], 3-day food diaries [ and 24 hr recalls [10,24,25,43]. Other studies used food diaries of different duration (i.e., 4-day, 6-day, and 8-day) [27,30,34], dietary recalls (i.e., 72-h) [26,36] and a combination of 4-day weighed food diary in addition to a food frequency questionnaire (FFQ) to assess dietary intake [

Nutrients2019,11, 1160 6 of 16 Table 4.Reported energy, macronutrient and micronutrients intakes of male and female professional and semi-professional team sport athletes. References Participant Characteristics Dietary Intake Data Author, Year Sport Country Level N (Gender) Total Mass (kg) Lean Mass (kg) BF% Energy Intake Reported (Estimated MJ Were Available) CHO (g) CHO (g kg 1 day 1 ) PRO (g) PRO (g kg 1 day 1 ) Fat (g) Fat (% TE) Calcium (mg day 1 ) Iron (mg day 1 ) Quality Rating Anderson et al. [23], (2017) Football (soccer) England P n=6 (male) 80.5 8.7 11.9 1.2 65.0 6.7 3186 585 kcal day 1 (13.3) 330 98 4.2 1.4 205 30 + Andrews and Itsiopoulus [25] (2016) Football (soccer) Australia P, SP n=73 (male) P 79.6 7.7 SP 75.6 7.6 P 11,525 1987 kJ day 1 SP 10,831 3842 kJ day 1 (P 11.5 2.0, SP 10.8 3.8) P 302.4 72.3 SP 298.7 148.5 P 3.5 0.8 SP 3.9 1.8 P 152.3 27.7 SP 149.1 46.8 P 1.9 0.3 SP 2.0 0.6 P 95.9 31.7 SP 85.8 37.8 P 30.4 7.3 SP 29.5 7.4 ; Bettonviel et al. [24] (2016) Football (soccer) Netherlands P n=14 (male) 77.0 8.6 2988 583 kcal day 1 (12.5) 365 76 4.7 0.7 145 24 1.9 0.3 97 26 29.0 3.6 ; Bilsborough et al. [26] (2016) Australian Football Australia P n=45 (male) 86.8 7.9 [7.9 1.8–10.5 2.7] [71.2 6.8–76.8 6.4] [11.1–13.9] [321 142–379 66] 4.1 1.6 [118 67–215 60] 1.9 0.9 [61 29–110 40] [19.0 5.0–33.1 6.7] ; Bradley et al. [27] (2015) Rugby Union Europe (non-speci ed) P n=14 (male) F 110 6.2 B 93.6 5.9 F 16.6 1.25 MJ day 1 B 14.2 1.20 MJ day 1 F 3.5 0.8 B 3.4 0.7 F 2.7 0.5 B 2.7 0.3 F 32 B 33 1733 694 24 9 ; Bradley et al. [10] (2015) Rugby Union Europe (non-speci ed) P n=20 (male) F 109.3 6.9 B 91.7 6.6 F 13 3 B 9.3 2 F 94.9 4.5, B 83.1 5.4 F 14.8 1.9 MJ day 1 B 13.3 1.9 MJ day

B 3.4 0.7 F 2.7 0.5 B 2.7 0.3 F 32 B 33 1733 694 24 9 ; Bradley et al. [10] (2015) Rugby Union Europe (non-speci ed) P n=20 (male) F 109.3 6.9 B 91.7 6.6 F 13 3 B 9.3 2 F 94.9 4.5, B 83.1 5.4 F 14.8 1.9 MJ day 1 B 13.3 1.9 MJ day 1 F 3.3 0.7 B 4.14 0.4 F 2.52 0.3 B 2.59 0.6 ; Conejos et al [28] (2011) Football (soccer) Spain P n=22 (male) Fwd. 12.7 2.9 MJ day 1 M 14.0 6.2 MJ day 1 D 14.8 2.6 MJ day 1 G 12.2 4.6 MJ day 1 Fwd. 342.5 92.9 M 382.1 187.2 D 419.1 98.3 G 320.3 11.9 Fwd. 138.7 27.5 M 144.8 56.9 D 144.5 19.9, G 142.8 100.1 Fwd. 120.3 59.6 M 131.6 62.6 D 124.5 36.1 G 109.8 45.3 Fwd. 34.7 M 35.6 D 32.2 G 34.9 Fwd. 1361.5 549.0 M 1592.3 966.1 D 1208.4 457.1 G 1499.7 1035.9 Fwd. 13.4 3.7 M 18.9 9.7 D 22.6 6.8 G 15.5 10.2 ; Devlin et al. [43] (2017) Australian Football (AF) Football (Soccer, F) Australia P, SP n=66 AF=48, F=18 (male) AF (P) 87.8 9.2 AF (SP) 82.9 9.0 F (P) 75.6 5.6 AF (P) 15.1 2.4, AF (SP) 16.7 2.7 F (P) 12.8 1.9 AF (P) 65.4 7.9 AF (SP) 61.2 3.9 F (P) 56.8 5.2 AF (P) 17.3 4.2 MJ day 1 AF (SP) 13.2 2.5 MJ day 1 F (P) 9.4 2.3 MJ day 1 AF (P) 406 132 AF (SP) 368 93 F (P) 220 76 AF (P) 4.6 1.5 AF (SP) 4.5 1.2 F (P) 2.9 1.1 AF (P) 295 97 AF (SP) 171 52 F (P) 140 35 AF (P) 3.4 1.1 AF (SP) 2.1 0.7 F (P) 1.9 0.5 AF (P) 29 6 AF (SP) 28 8 F(P) 33 9 ; Grams et al. [29] (2016) Wheelchair basketball Spain P n=17 (male) 75.5 13.5 2673 485 kcal day 1 (11.2) 3.9 [Range: 1.8–8.1] 1.7 0.6 33.7 5.5 + Gravina et al. [30] (2012) Football (soccer) Spain P, SP

The review highlights dietary intake inadequacies among team sport athletes.