Dietary patterns are prerequisites for health and integral components of ecological systems. For over a century researchers have been building a body of evidence of associations between dietary patterns and health and sustainability outcomes while policymakers have been synthesising and translating this evidence into policies to promote public health. During this period, food systems have dramatically changed and driven the emergence of food supplies and dietary behaviours with no ecological or evolutionary precedent. Now, the relevance of conventional nutrition research and policymaking approaches for understanding food system transitions and protecting against unhealthy and unsustainable diets is being questioned. This review aims to examine how the ecological nutrition paradigm might guide a transformed approach to nutrition research and policymaking to promote healthy and sustainable diets. It shows the ecological nutrition paradigm is transdisciplinary integrating biological, social and environmental dimensions into nutrition research and policymaking. The paradigm operates to a ‘fit-for-purpose’ policymaking orientation. It draws on ecological and evolutionary theories to provide insights to conceptualise the causes of, and solutions to, nutrition problems and help design relevant decision-making processes. These research and policymaking features contrast with the ‘one-size-fits-all’ policymaking orientation and prescriptive decision-making processes of the conventional medical nutrition paradigm. Their attention to a relevance criterion engenders confidence in the likely effectiveness, and ability to avoid unintended consequences, of policies informed within an ecological nutrition paradigm. The review proposes a shift to the ecological nutrition paradigm to transform nutrition research and policymaking for promoting healthy and sustainable diets is overdue.

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.