Food-based diet indices provide a practical, rapid, and inexpensive way of evaluating dietary intake. Rather than nutrients, diet indices assess the intake of whole foods and dietary patterns, and compare these with nutrition guidelines. An athlete-specific diet index would offer an efficient and practical way to assess the quality of athletes’ diets, guide nutrition interventions, and focus sport nutrition support. This study describes the development and validation of an Athlete Diet Index (ADI). Item development was informed by a review of existing diet indices, relevant literature, and in-depth focus groups with 20 sports nutritionists (median of 11 years’ professional experience) from four elite athlete sporting institutes. Focus group data were analyzed (NVivo 11 Pro; QSR International Pty. Ltd., 2017, Melbourne, Australia), and key themes were identified to guide the development of athlete-relevant items. A modified Delphi survey in a subgroup of sports nutritionists (n = 9) supported item content validation. Pilot testing with athletes (n = 15) subsequently informed face validity. The final ADI (n = 68 items) was categorized into three sections. Section A (n = 45 items) evaluated usual intake, special diets or intolerances, dietary habits, and culinary skills. Section B (n = 15 items) assessed training load, nutrition supporting training, and sports supplement use. Section C (n = 8 items) captured the demographic details, sporting type, and caliber. All of the athletes reported the ADI as easy (40%) or very easy (60% of participants) to use and rated the tool as relevant (37%) or very relevant (63% of participants) to athletes. Further evaluation of the ADI, including the development of a scoring matrix and validation compared with established dietary methodology, is warranted.
Capling, Gifford, Flood, and O’Connor are with the Discipline of Exercise and Sport Science, Faculty of Health Sciences, The University of Sydney, Lidcombe, New South Wales, Australia. Beck is with the School of Sport, Exercise and Nutrition, College of Health, Massey University, Auckland, New Zealand. Flood, O'Connor and Gifford are with Charles Perkins Centre, The University of Sydney, Camperdown, New South Wales, Australia. Flood is also with Western Sydney Local Health District, Westmead, New South Wales, Australia. Slater is with the School of Health and Sport Sciences, University of the Sunshine Coast, Maroochydore, Queensland, Australia, and the Australian Institute of Sport, Canberra, Australian Capital Territory, Australia. Denyer is with the School of Life and Environmental Sciences, The University of Sydney, Camperdown, New South Wales, Australia. Capling is also with Sport Performance Innovation and Knowledge Excellence, Queensland Academy of Sport, Brisbane, Queensland, Australia.