Dietary Recommendations for Body Mass and Composition Manipulation in Male and Female Athletes: a Scoping Review of Consensus Statements, Position Stands and Practice Guidelines from International Expert Groups.

backgroundBody mass and composition (fat and fat-free mass) manipulation is a common practice in sport, yet it can pose significant risks to athlete health and wellbeing. Practitioners must continually adapt to the growing body of evidence to implement safe, effective and context-specific practice.

objectiveThis scoping review aimed to summarise dietary recommendations for altering body mass or composition in male and female, adult non-disabled athletes and appraise how these expert-group led recommendations have evolved over time.

methodsElectronic databases, including SCOPUS, PubMed, SPORTDiscus, CINAHL Complete and APA PsycINFO were searched (last search 2 August 2024) without date restrictions. Papers were included if they provided dietary recommendations for altering body mass or composition in adult non-disabled athlete populations and were published by an expert organisation.

resultsFrom 6068 records screened, 73 documents were included, comprising 45 consensus statements, 27 position stands and 1 practice guideline, endorsed by 14 organisations and developed by 328 experts from 25 countries. Athletics (n = 19), aquatics (n = 7) and team sports (n = 5) were the most represented, leaving many sports underrepresented. A total of 50 documents were standalone rather than part of an updated series. Only 40 papers addressed specific targets, rates or timing of outcome changes. Individualised, realistic and health-focussed targets were recommended, aligned with the athlete's sport, position, sex, age and competition phase, with gradual changes (e.g. 0.5-1.0 kg/week fat loss) to enhance performance. Common strategies for altering body mass and composition included creating an energy surplus (500-1000 kcal/day) or deficit (250-1000 kcal/day), maintaining energy availability above 30 kcal/kg fat-free mass/day, and periodising carbohydrate intake (3-12 g/kg/day) on the basis of training demands. Protein intake (1.6-2.4 g/kg/day) was recommended across 4-6 feeds from high-quality sources, alongside targeted supplements such as creatine, whey protein and a multi-vitamin and mineral. Recommendations focussed minimal attention on nutrients such as fats, fibre or micronutrients, and the language used was often vague, leaving significant room for interpretation.

conclusionsDeveloping sport-specific, behaviourally anchored and regularly updated dietary recommendations, informed by athlete and multidisciplinary team input, is recommended. This approach would provide actionable, athlete-centred strategies that effectively support body composition goals whilst prioritising health, wellbeing and performance. OSF Registration https://doi.org/10.17605/OSF.IO/B4YJT.