Witkam Rozemarijn, Brealey Jane, Latham Rebecca, Jones Andrew, Robinson Eric
Department of Psychology, Institute of Population Health, University of Liverpool, Liverpool, UK.
School of Psychology, Faculty of Health, Liverpool John Moores University, Liverpool, UK.
BMC Public Health. 2025 May 22;25(1):1893. doi: 10.1186/s12889-025-21992-1.
Frequent out-of-home food sector (OOHFS) use is associated with poor dietary intake and obesity. There are limited real-world studies on pricing interventions to encourage healthy eating in the OOHFS. We performed a pilot study to collect preliminary trial data on the potential impact of a price reduction intervention on healthier menu items on purchasing and consumption of kilocalories (kcal) in a full-serviced restaurant among people from both lower and higher socioeconomic position (SEP).
The main trial design was a pre vs. post price reduction comparison (within-subjects), where participants (adults aged ≥ 18 years) received a control menu with standard pricing at visit 1 and a menu with price manipulations (30% reduction for healthy items) at visit 2. A sub-study was conducted with a comparison sample to estimate potential pre-post changes to outcome variables in the absence of a pricing intervention. Linear mixed models assessed pre-post changes in kcal purchased and kcal consumed.
In total, 114 participants were recruited; 92 were randomised to the main study and 22 to the comparison sub-study. Of those participating in the main study, 78 completed and 14 were lost to follow-up. There were no participants lost to follow-up in the comparison study. Of the completers, 46 participants were considered higher SEP (i.e. bachelor's degree or higher) and 32 participants were lower SEP (i.e. some college or associate degree or lower). Kcal purchased and consumed decreased from visit 1 to visit 2; however, this reduction was only statistically significant for total kcal consumed (regression coefficient: -98.0 (95% CI -181.9, -14.2), p = 0.02). There were no notable intervention effect differences between higher and lower SEP participants, but we were under-powered to formally test for SEP differences. In the comparison study, kcal purchased and consumed was also lower at visit 2 compared to visit 1, although this should be interpreted with caution due to the small sample size.
A price reduction intervention on lower energy menu items is potentially effective in encouraging healthier eating in a restaurant setting. Larger studies with inclusion of a control group (e.g., randomised controlled trials) are now needed to confirm intervention effects and whether they are equitable across different socioeconomic groups.
经常在家庭外食品部门（OOHFS）消费与不良饮食摄入和肥胖有关。关于定价干预措施以鼓励在家庭外食品部门健康饮食的实际研究有限。我们进行了一项试点研究，以收集关于降价干预对全服务餐厅中不同社会经济地位（SEP）人群购买和摄入卡路里（千卡，kcal）的潜在影响的初步试验数据。
主要试验设计为降价前与降价后的比较（受试者内），参与者（年龄≥18岁的成年人）在第1次就诊时收到标准定价的对照菜单，在第2次就诊时收到有价格调整的菜单（健康菜品降价30%）。进行了一项子研究，采用比较样本以估计在无定价干预情况下结果变量的潜在前后变化。线性混合模型评估购买的千卡和摄入的千卡的前后变化。
总共招募了114名参与者；92名被随机分配到主要研究，22名被分配到比较子研究。参与主要研究的人中，78人完成研究，14人失访。比较研究中无失访参与者。在完成研究的人中，46名参与者被认为社会经济地位较高（即学士学位或更高），32名参与者社会经济地位较低（即大专或副学士学位或更低）。从第1次就诊到第2次就诊，购买和摄入的千卡减少；然而，这种减少仅在总摄入千卡方面具有统计学意义（回归系数：-98.0（95%CI -181.9，-14.2），p = 0.02）。社会经济地位较高和较低的参与者之间没有显著的干预效果差异，但我们的样本量不足以正式检验社会经济地位差异。在比较研究中，与第1次就诊相比，第2次就诊时购买和摄入的千卡也较低，不过由于样本量小，对此应谨慎解读。
对低能量菜单项的降价干预可能有效地鼓励在餐厅环境中更健康地饮食。现在需要开展纳入对照组的更大规模研究（如随机对照试验），以确认干预效果以及它们在不同社会经济群体中是否公平。
