Nutrition has long been an important consideration for optimal sporting performance and recovery, athlete well-being and the modulation of injury risk. Ensuring that athletes follow dietary patterns that are nutrient-dense and facilitate the meeting of energy and macronutrient requirements is a crucial part of the sports nutrition practitioners’ role. Furthermore, the practitioner should facilitate athletes understanding of meal timing and its potential benefit towards optimising performance and recovery. The accurate collection and interpretation of dietary intake data and provision of appropriate support towards athletes meeting overall nutrient requirements, promoting adherence to macro and micronutrient- dense dietary patterns and manipulation of meal timing may thus facilitate optimal performance and recovery. The emergence of the SARS-CoV-2 virus in December 2019 and subsequent global spread saw the World Health Organisation declare a pandemic. As a result, governments and local authorities implemented a variety of restrictions to minimise the spread of the virus. In March 2020, New Zealand enforced strict lockdown restrictions that saw the forced closure of shops, restaurants, gyms and training facilities alongside mask requirements, social distancing, and the encouragement of more intensive hygiene procedures. As such, the purpose of Chapter 3 was to report the perceived influence of such restrictions on nutrition and training habits in rugby players. Changes in living situations were reported in response to lockdown restrictions, and diet quality may have improved, with limited respondents reporting reduced fruit and vegetable intake and increased packaged and convenience food intake. Furthermore, participants reported a reduction in motivation to exercise and train during lockdown, with follow-up survey responses indicating positive changes once restrictions were lifted. A variety of sources of nutrition information aside from dieticians or nutritionists were reported by participants including coaching staff, team-mates, family, social media, and the internet. Collectively, the data indicate that unexpected events such as the emergence and global spread of the SARS-CoV-2 virus can influence athletes’ dietary choices and nutrition practitioner support may be valuable for ensuring athletes make appropriate dietary choices during times of reduced training volume to maintain lean mass, adaptations, health and mitigate injury risk upon the return to play. The use of technology to assist and facilitate the monitoring and analysis of dietary intake has gained popularity in both research and practice due to less participant burden and the potential for more accurate information. Despite this, the practical validity of such tools is unknown. The findings of Chapter 4 indicate that the remote food photography method application utilised in this thesis demonstrates ecological validity on a group level in athletic individuals. Despite this, significant individual variability is present, with inter-individual discrepancy in the % difference in calculated energy and macronutrient values. As such, the findings of this data suggest the remote food photography method may be beneficial for providing group level recommendations; however, individual intakes must be interpreted with caution. In Chapter 5, the daily distribution patterns of professional and semi-professional rugby players were investigated. Rugby players may benefit from consideration of protein distribution, with mechanistic research suggesting an even spread of 0.4g‧kg‧d across 4 – 6 meals may result in a more optimal anabolic response; as such, adherence to such a pattern may optimise recovery, physiological adaptations, and performance. The data in Chapter 5 are in alignment with patterns presented in other athletic disciplines, whereby sub-optimal consumption is reported at snacks and only two eating occasions meeting the proposed 0.4g‧kg threshold for eliciting an optimal anabolic response. The manipulation of daily protein distribution was to be applied as an intervention in response to the findings in Chapter 5 to investigate the influence of optimised patterns on body composition, performance variables and well-being; however, it was determined following initial monitoring of the participants’ dietary intake that requirements based on best- practice literature and recommendations were not being met. As such, the intervention reported in Chapter 6 was adapted to investigate how the implementation of full-time nutrition practitioner support delivered over a four-week period in an environment where prior support was minimal influenced total and per-meal nutrient intake, nutrition knowledge, body composition and well-being in provincial academy rugby players. Significant increases following intervention delivery were observed for total energy and protein intake. Additionally, consumption of protein at the breakfast, post-gym and snack eating occasions was greater. Carbohydrate intake pre-gym significantly increased in response to the intervention whilst consumption at PM snack and dinner was reduced. The development and execution of the research contained in this thesis demonstrates the unpredictable and volatile nature of working in performance environments. Furthermore, major challenges during the nutrition support process, as would be delivered by sports nutrition practitioners, may influence the quality-of-service provision. As summarized in Chapter 7, the research in this thesis provides novel insight into the influence of full-time nutrition support when delivered by practitioners over a four-week period; as such, future research should further bridge the gap between research and practice by analysing the impact of nutrition support over prolonged periods. Additionally, incorporating qualitative data collection will allow for the better understanding of athletes’ perceptions of current and desired nutrition support, how the inclusion of nutrition support benefits their perceptions of performance and well-being, and how well- received the inclusion of nutrition support would be. Additionally, future research should aim to build upon the themes introduced in this thesis and explore how the manipulation of dietary protein intake influences athlete-specific performance and adaptation, allowing for the creation of sport-specific, evidence-informed recommendations.