Background: The Eatwell Guide represents the UKs principal healthy eating model and understanding whether adherence to UK dietary recommendations can attenuate age-related functional decline is essential to inform healthy ageing strategies. Methods: In up to 157,457 participants from the UK Biobank, we explored cross-sectional and prospective associations between adherence to the Eatwell Guide and markers of physical function (grip strength, fat-free mass percentage, self-reported walking pace, and falls). Eatwell Guide adherence scores were derived from 24-hour dietary recall data (Oxford WebQ), and quantified using a graded, food-based scoring system. Differences between population subgroups including by age, sex, physical activity, and protein intake level were explored. Results: Higher Eatwell Guide adherence was cross-sectionally associated with higher grip strength, greater fat-free mass percentage, higher odds of brisk walking pace, and lower odds of falls (all p