Wolfswinkel Sofia M M, Raghoebar Sanne, Stuber Josine M, de Vet Emely, Poelman Maartje P
Consumption & Healthy Lifestyles Group, Wageningen University & Research, Wageningen, The Netherlands.
Epidemiology and Data Science, Amsterdam UMC Location Vrije Universiteit Amsterdam, De Boelelaan 1117, Amsterdam, The Netherlands.
BMC Med. 2025 Mar 11;23(1):150. doi: 10.1186/s12916-025-03986-3.
Communicating (dynamic) social norms is considered a promising tool to stimulate healthy and sustainable food choices. The aim of the present study was to evaluate to what extent a (dynamic) social norm intervention in real-world supermarkets could increase sales (grams per week) of meat alternatives (i.e. meat substitutes and legumes).
A quasi-experimental study, including three intervention and three control supermarkets, was conducted during a 12-week period. The intervention supermarkets communicated dynamic norms textually on stickers and banners at different in-store locations (e.g. at the entrance, meat aisles). Moreover, the prominence of meat substitutes was (optically) increased and legumes were conveniently placed near the meat and meat substitutes section. Weekly sales data over a period of 75 weeks were obtained, 62 pre-intervention and 13 during intervention. Comparative interrupted time series analyses were conducted to analyse changes in meat alternative sales (in grams) during the intervention period in the intervention supermarkets compared to pre-intervention sales trends and to control supermarkets. Secondary outcomes included meat sales in grams per week and the ratio of protein content of meat alternatives to protein content of meat sales.
Average meat alternative sales in weekly grams before the intervention were M = 371,931.2 (SD = 113,055.3) in the control supermarkets and M = 299,012.5 (SD = 91,722.8) in the intervention supermarkets. The intervention did not change meat alternative sales in intervention supermarkets compared to pre-implementation sales trends and to control supermarkets (B = - 685.92, 95% CI [- 9904.8; 8525.7]). Sales of meats were also unaffected (B = - 130.91, 95% CI [- 27,127.50; 26,858.33]), as well as the ratio of protein content of meat alternatives to protein content of meat in grams sold per week (B = - 670.54, 95% CI [- 8990.6; 7644.4]).
Communicating (dynamic) social norms via textual and environmental cues (i.e. increasing the prominence of meat alternatives in supermarkets) did not increase meat alternative sales nor reduce meat sales. With supermarkets playing an important role in modulating sustainable food choices, more substantial effort or changes are needed to increase plant-based food purchases and lower meat purchases.
传达（动态）社会规范被认为是促进健康和可持续食品选择的一种有前景的工具。本研究的目的是评估在现实世界的超市中进行的（动态）社会规范干预能在多大程度上增加肉类替代品（即肉类替代品和豆类）的销售量（每周克数）。
进行了一项准实验研究，包括三家干预超市和三家对照超市，为期12周。干预超市在店内不同位置（如入口、肉类过道）通过贴纸和横幅以文字形式传达动态规范。此外，肉类替代品的显眼程度（在视觉上）有所提高，豆类被方便地放置在肉类和肉类替代品区域附近。获取了75周期间的每周销售数据，干预前62周，干预期间13周。进行了比较中断时间序列分析，以分析干预超市在干预期间与干预前销售趋势以及对照超市相比，肉类替代品销售量（克数）的变化。次要结果包括每周肉类销售量（克数）以及肉类替代品蛋白质含量与肉类销售蛋白质含量的比率。
干预前，对照超市每周肉类替代品平均销售量（克数）为M = 371,931.2（标准差 = 113,055.3），干预超市为M = 299,012.5（标准差 = 91,722.8）。与干预前销售趋势以及对照超市相比，干预并未改变干预超市的肉类替代品销售量（B = -685.92，95%置信区间[-9904.8；8525.7]）。肉类销售量也未受影响（B = -130.91，95%置信区间[-27,127.50；26,858.33]），每周销售的肉类替代品蛋白质含量与肉类蛋白质含量的比率也未受影响（B = -670.54，95%置信区间[-8990.6；7644.4]）。
通过文字和环境提示传达（动态）社会规范（即提高超市中肉类替代品的显眼程度）并未增加肉类替代品销售量，也未减少肉类销售量。鉴于超市在调节可持续食品选择方面发挥着重要作用，需要做出更大的努力或改变，以增加植物性食品的购买量并减少肉类购买量。
