Dietary Periodicity Disrupts the Gut Microbiota-Enterolactone Axis to Exacerbate MASLD in a Translational Guinea Pig Model.

Optimal nutritional strategies are important for supporting athletic performance, recovery, and overall athlete health []. Despite growing awareness of sports nutrition, many athletes fail to meet current nutritional recommendations []. Female athletes may be particularly vulnerable to inadequate energy and nutrient intake, including inadequate iron, vitamin D, and calcium intake []. These inadequacies may negatively impact performance and contribute to health consequences, including menstrual dysfunction, impaired bone health, increased injury risk, and illness []. Collectively, these physiological consequences are described within the framework of Relative Energy Deficiency in Sport (RED-S), for which low energy availability (LEA) is considered the primary underpinning factor []. Energy availability (EA) is defined as the amount of dietary energy remaining to support physiological function after exercise energy expenditure has been subtracted from energy intake, relative to fat-free mass (FFM) []. LEA occurs when insufficient energy remains to adequately support normal physiological processes and athlete health []. Despite emerging evidence indicating individual variation in response to LEA, it is commonly defined as <30 kcal/kg FFM/day []. Direct assessment of EA can be methodologically challenging in free-living athletes because accurate measurement of both dietary intake and exercise energy expenditure is required []. Consequently, screening tools such as the Low Energy Availability in Females Questionnaire (LEAF-Q) are commonly used to identify female athletes at risk of LEA []. Recent studies have identified a high prevalence of LEA risk across female team sports, including Australian football, soccer, rugby, and Gaelic games athletes [,,,,,]. Nutrition knowledge (NK) is considered an important and potentially modifiable determinant of dietary behaviour in athletes []. While greater NK has been associated with healthier dietary patterns and improved dietary intake in some athlete populations [,,], emerging evidence suggests that NK alone may not consistently translate into optimal nutritional practices or reduced LEA risk []. Previous research also suggests that NK may be influenced by educational attainment, previous nutrition education, and athletic level, although findings remain inconsistent across sporting populations [,,]. Understanding how NK differs according to these athlete characteristics may help identify athletes who would benefit most from targeted nutrition education interventions []. Furthermore, the amateur nature of field-based team sports such as Gaelic football presents additional challenges to accessing qualified nutrition support, with potential implications for NK and dietary behaviours []. However, inadequate energy intake is multifactorial, with behavioural, environmental, and psychosocial factors also contributing to LEA risk. Consequently, the relationship between NK and LEA risk remains unclear, particularly in female team sport athletes.