Objective: This study aimed to assess and comparatively analyse two menus from a Young Offenders Institution (YOI). One menu from 2019, and one from 2022, with the objective of identifying any improvements in meeting dietary guidelines. Design: Cross-sectional and comparative analysis. Setting: United Kingdom, a YOI in Northern England. Participants: YOI Menus. Results: Analysis of 30 dietary components identified that 25 exceeded the dietary guidelines (P < 0.05) for the 2022 menu, with five failing to meet the guidelines (P < 0.05). When compared to the 2019 menu, the 2022 menu showed improvements in saturated fat, sodium, and vitamin D. Despite the improvement, vitamin D levels remained below dietary guidelines (P < 0.01). Salt and energy content were reduced in the 2022 menu (P < 0.05); however, they were still above the dietary guidelines (P < 0.01). Free sugars were significantly above dietary guidelines for both menus, with no significant change between the 2019 and 2022 menu (P = 0.12). Conclusion: The 2022 menu has demonstrated progress in alignment with meeting dietary guidelines, particularly in reducing calories, fat, saturated fat, salt, sodium, and chloride, as well as increasing vitamin D. Despite improvements, calories, free sugars, salt, saturated fat, sodium, and chloride are still exceeding dietary guidelines, posing as potential health risks.