Neil Irwin: Exploring Nutrition Knowledge, Dietary Intake, and Influencing Factors in Youth Team Sport Athletes.
My Background
Since 2019, I have worked as a Performance Nutritionist with the Dublin Senior Men’s Football Team. Through my applied work, I have noticed clear trends in youth athletes progressing from underage panels, often arriving with limited nutrition support, low nutrition knowledge, and poor dietary habits. Many were falling short of sports nutrition recommendations, affecting their ability to meet energy demands, recover effectively, and adapt to training. Over the past two years, I’ve led the development of a structured nutrition support system across Dublin GAA’s underage pathways. I have observed clear improvements in both knowledge and dietary behaviours, leading to greater confidence, consistency, and performance. My practical work and the lack of research in this population have directly informed my current research, and I am now in the second year of a PhD at the Technological University of the Shannon (TUS), funded by Research Ireland, and supervised by Dr David Kelly and Dr Ciarán Ó Catháin. My research explores dietary practices, nutrition knowledge, and influencing factors among youth GAA athletes.
Research Project
Aim and Scope
As part of my PhD, I have conducted a scoping review to examine current evidence on dietary intake, nutrition knowledge, and behavioural influences in youth team sport athletes aged 12 to 19. The aim was to map what young athletes eat, what they know about nutrition, and the factors shaping those behaviours.
Methods
The review followed PRISMA-ScR guidelines and was pre-registered on the Open Science Framework. Searches were conducted across five databases (PubMed, MEDLINE, PsycINFO, SPORTDiscus, and grey literature). Studies were included if they addressed dietary intake, nutrition knowledge, or influencing factors in youth team sport athletes. Screening and data extraction were completed independently by two reviewers.
Fifty-seven studies met the inclusion criteria, involving 4,369 youth athletes across 16 countries. Soccer was the most commonly studied sport (64.9%), followed by basketball (17.5%) and rugby (15.8%). Gaelic Games and other sports were also represented. Male athletes made up 72.5% of the sample, while only 14% of studies focused solely on females. Most studies used cross-sectional designs (57.9%), and although 34 were rated high quality, only 12.3% reported statistical power, highlighting the need for more rigorous and inclusive research.
Key Findings
Several consistent findings emerged across the included studies. Many youth athletes were not meeting energy requirements, with notable carbohydrate shortfalls, particularly on training and match days. Protein intake was generally adequate but often poorly distributed across the day, which may compromise recovery and muscle adaptation (Mamerow et al., 2014). Fat intake also typically met recommendations, but a trend toward higher saturated fat consumption was observed. Micronutrient intake, particularly for vitamin D, calcium, and iron, was frequently below recommended levels, often linked to low fruit and vegetable consumption.
Nutrition knowledge was generally poor to moderate. Athletes commonly lacked sport-specific understanding, and few studies used tools validated for adolescent populations. Although intervention studies showed modest gains in knowledge, these improvements rarely translated into sustained changes in dietary behaviour.
Dietary habits were shaped by a range of social and environmental influences, including access to food, time constraints, motivation, and the presence or absence of support from parents, coaches, and peers. These findings underscore the multifactorial nature of dietary behaviour in youth athletes, indicating that standalone education strategies are unlikely to achieve meaningful or sustained impact.
Key Considerations for Researchers
This review identified several methodological limitations that affect the strength and applicability of current evidence. Most studies used cross-sectional designs, limiting insight into how nutrition knowledge and behaviours evolve during adolescence. Statistical power calculations were rarely reported, and dietary intake data were often collected using inconsistent or unvalidated methods, reducing reliability and comparability. Future research would benefit from longitudinal designs, validated tools, adjustment for misreporting, and standardised reporting units. Female athletes remain under-represented, and sex-specific analyses are uncommon, highlighting the need for more inclusive approaches. Nutrition knowledge was frequently assessed using adult-based or unvalidated tools, and therefore, future studies should prioritise validated, adolescent-specific instruments. Finally, few interventions included follow-up or explored behaviour change mechanisms, making it difficult to evaluate their long-term effectiveness. Applying behaviour change theory and assessing sustained outcomes could enhance the impact and relevance of future interventions.
Key Considerations for Practitioners
Supporting youth team sport athletes requires attention to both the physical demands of training and the unique developmental needs of adolescence. Energy deficits were frequently observed, particularly on match days and during high-intensity training, often due to inadequate carbohydrate periodisation. Athletes commonly consumed similar carbohydrate amounts regardless of training load, impairing glycogen replenishment, recovery, and performance. Structured tools such as fuelling calendars, checklists, and practical education may help athletes better align intake with daily demands.
Protein intake was generally adequate but often concentrated at dinner, with lower intake at breakfast. Encouraging a more even distribution throughout the day, particularly increasing intake in the morning, may enhance muscle protein synthesis, support recovery, and promote adaptation. Low fruit and vegetable intake was also common, contributing to micronutrient deficiencies. Practical, age-appropriate strategies to increase plant-based foods could support immunity, bone health, and overall dietary quality.
Dietary behaviours were shaped by a mix of social, environmental, and motivational factors. While parents and coaches play a key role, inconsistent role modelling and limited food access can undermine positive intentions. Interventions may be more effective when they engage the wider support network and incorporate behaviour change techniques, such as goal setting, self-monitoring, and supportive environments. Finally, given the dynamic nature of growth and training demands during adolescence, nutrition support should be regularly reviewed and adapted to meet evolving needs.
Mamerow MM, Mettler JA, English KL, Casperson SL, Arentson-Lantz E, Sheffield-Moore M, et al. Dietary Protein Distribution Positively Influences 24-h Muscle Protein Synthesis in Healthy Adults. The Journal of Nutrition. 2014 Jun;144(6):876–80.
Author Bio
Neil Irwin is a Registered Practitioner on the Sport and Exercise Nutrition Register (SENR) and Head of Nutrition with Dublin Senior Men’s Football. He is a second-year PhD candidate at TUS, funded by the Irish Research Council, researching nutrition knowledge and dietary intake in youth GAA athletes. Neil has worked with Ireland’s senior men’s hockey squad and currently leads nutrition education initiatives across Dublin GAA’s youth development pathways.