Male volleyball athletes may be at risk of inadequate energy and carbohydrate intake. This may increase their risk of relative energy deficiency in sport (REDs) and impair a variety of physiological and psychological systems involved with performance and health. This study explored the eating behaviours and diet quality of international elite volleyball male athletes and their association on hormones associated with acute energy deficit and primary serum REDs indicators outlined in the International Olympic Committee REDs Clinical Assessment Tool 2. Methods: Using a retrospective design, 30 male athletes from a national indoor volleyball programme were assessed using DXA bone mineral density, hematological analysis, anthropometry, restrained eating behaviour via the Three-Factor Eating Questionnaire-R18 and the Athlete Diet Index (ADI) questionnaire. Results: All participants met or exceeded dietary recommendations for health and sport with ADI mean score of 95.2/125 ± 10.5. Restraint eating was inversely associated with insulin (r = − 0.37; p  < 0.05). Both the ADI total and core nutrition sub-scores were inversely associated with free-triiodothyronine (r = − 0.58; p < 0.01) but not with total testosterone, insulin or leptin. Conclusion: Male volleyball athletes at risk of inadequate energy intake may not necessarily demonstrate signs of poor diet quality.