METHODS: Product-level sales data and energy content of available items was obtained from 142 worksite cafeterias from January 2022-October 2022. Interrupted-time-series (ITS) analysis with level and slope change evaluated daily energy (kcal) purchased per item, and ITS with level change assessed mean energy per option available on menus before and after calorie labelling. Each analysis was conducted 6 weeks and 6 months from implementation. A post-hoc ITS examined weekly energy purchased per item over a longer period (March 2021-October 2022; 135 sites).
RESULTS: There was no evidence calorie labelling changed the energy content of foods purchased (6-week: + 0.60 cal/product, 95%CI:-2.54, + 3.75; 6-month: + 1.59 cal/product, 95%CI:-0.96, + 4.16). Post-hoc analyses suggested calorie labels were associated with a reduction in mean energy of items purchased over time (-0.65 kcal/week, 95%CI:-0.81,-0.49), but a significant increase (+ 3 kcal, 95%CI: + 0.43, + 5.60) at the point of implementation. There was a reduction in the mean energy content of menu options at each seasonal menu change (April 2022:-1.79 kcal, 95%CI:-3.42,-0.15; July 2022:-4.18 kcal, 95% CI:-7.65,-0.73).
CONCLUSIONS: This large observational study in worksite cafeterias found no evidence to indicate the introduction of calorie labelling led to any immediate reduction in energy purchased by customers. There was some evidence of increasing impact over time, possibly associated with changes in menu offerings, but this effect was small and cannot be directly attributed to calorie labelling.
方法:从2022年1月至2022年10月,从142个工地自助餐厅获得了产品级销售数据和可用物品的能量含量。具有水平和斜率变化的中断时间序列(ITS)分析评估了每件物品购买的每日能量(kcal),和ITS,其水平变化评估了卡路里标签前后菜单上每个选项的平均能量。每个分析在实施后6周和6个月进行。事后ITS检查了更长时期内(2021年3月至2022年10月;135个站点)的每个项目每周购买的能源。
结果:没有证据表明卡路里标签会改变购买食品的能量含量(6周:0.60cal/产品,95CI:-2.54,+3.75;6个月:+1.59卡/产品,95CI:-0.96,+4.16)。事后分析表明,随着时间的推移,卡路里标签与购买物品的平均能量减少相关(-0.65千卡/周,95CI:-0.81,-0.49),但显著增加(+3千卡,95CI:+0.43,+5.60)在实施时。每次季节性菜单更改时,菜单选项的平均能量含量都会减少(2022年4月:-1.79千卡,95CI:-3.42,-0.15;2022年7月:-4.18大卡,95%CI:-7.65,-0.73)。
结论:这项在工作场所自助餐厅进行的大型观察性研究没有发现任何证据表明引入卡路里标签会导致客户购买的能量立即减少。有一些证据表明,随着时间的推移,影响越来越大,可能与菜单产品的变化有关,但这种影响很小,不能直接归因于卡路里标签。