Mandatory calorie labelling was introduced in out-of-home (OOH) food sector outlets during 2022 in England. Previous research in North America has found labelled energy content can be underestimated for packaged and quick-serve foods, but no study has evaluated the accuracy of out-of-home food sector menu calorie labelling in response to the mandatory policy introduced in England. N=295 menu items from a range of outlet types (e.g. cafes, pubs, restaurants) and menu categories (e.g., starters and sides, main, dessert) were sampled. Bomb calorimetry was used to quantify energy content and the reported energy content on menus was recorded. Consistency of measured energy was assessed by sampling the same items across outlets of the same business (N=50 menu items). Differences between reported and measured energy content were tested through Wilcoxon Signed Rank tests, and a linear model examined correlates of the difference. Mean measured kilocalories (kcal) were significantly lower than reported kcal (-16.70kcal (SD:149.19), V=16920, p<.01, r=0.182). However, both over- and under-estimation of measured energy content was common and the averaged absolute percentage difference between reported and measured values was 21% (SD:29%). Discrepancy between measured and reported energy content was more common in some outlet types (pubs) and reported energy content was substantially different (>20%) to measured energy content for 35% of sampled menu items. There were significant inaccuracies in reported energy content of calorie labelled menu items in English food outlets subject to mandatory calorie labelling and this appears to be caused by both over- and under-estimation of reported energy content.

ER has previously received research funding from Unilever and the American Beverage Association for unrelated research projects. Other authors have no competing interests.

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This piece of work was primarily funded by the University of Liverpool Policy Support Fund. AF and ERs salary is supported by an ESRC grant (ES/W007932/1). ER is funded by the National Institute for Health and Care Research (NIHR) Oxford Health Biomedical Research Centre (BRC). JA is supported by the Medical Research Council [grant number MC_UU_00006/7]. MP receives support from the NIHR Applied Research Collaboration ARC NWC and Alzheimers Society and is funded through a Post-Doctoral Fellowship.

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