School of Population Health, The University of Auckland, Auckland, New Zealand.
Am J Clin Nutr. 2010 Mar;91(3):736-47. doi: 10.3945/ajcn.2009.28742. Epub 2009 Dec 30.
Traditional methods to improve population diets have largely relied on individual responsibility, but there is growing interest in structural interventions such as pricing policies.
The aim was to evaluate the effect of price discounts and tailored nutrition education on supermarket food and nutrient purchases.
A 2 x 2 factorial randomized controlled trial was conducted in 8 New Zealand supermarkets. A total of 1104 shoppers were randomly assigned to 1 of the following 4 interventions that were delivered over 6 mo: price discounts (12.5%) on healthier foods, tailored nutrition education, discounts plus education, or control (no intervention). The primary outcome was change in saturated fat purchased at 6 mo. Secondary outcomes were changes in other nutrients and foods purchased at 6 and 12 mo. Outcomes were assessed by using electronic scanner sales data.
At 6 mo, the difference in saturated fat purchased for price discounts on healthier foods compared with that purchased for no discount on healthier foods was -0.02% (95% CI: -0.40%, 0.36%; P = 0.91). The corresponding difference for tailored nutrition education compared with that for no education was -0.09% (95% CI: -0.47%, 0.30%; P = 0.66). However, those subjects who were randomly assigned to receive price discounts bought significantly more predefined healthier foods at 6 mo (11% more; mean difference: 0.79 kg/wk; 95% CI: 0.43, 1.16; P < 0.001) and 12 mo (5% more; mean difference: 0.38 kg/wk; 95% CI: 0.01, 0.76; P = 0.045). Education had no effect on food purchases.
Neither price discounts nor tailored nutrition education had a significant effect on nutrients purchased. However, the significant and sustained effect of discounts on food purchases suggests that pricing strategies hold promise as a means to improve population diets.
传统的改善人群饮食的方法在很大程度上依赖于个人责任，但人们对定价政策等结构性干预措施的兴趣日益浓厚。
评估价格折扣和定制营养教育对超市食品和营养购买的影响。
在新西兰的 8 家超市进行了一项 2 x 2 析因随机对照试验。共有 1104 名购物者被随机分配到以下 4 种干预措施中的 1 种，持续 6 个月：更健康食品的 12.5%折扣、定制营养教育、折扣加教育或对照组（无干预）。主要结局是 6 个月时购买的饱和脂肪量的变化。次要结局是 6 个月和 12 个月时购买的其他营养素和食品的变化。使用电子扫描仪销售数据评估结果。
在 6 个月时，与更健康食品的无折扣相比，更健康食品的价格折扣购买的饱和脂肪量差异为-0.02%（95%CI：-0.40%，0.36%；P=0.91）。与无教育相比，定制营养教育的差异为-0.09%（95%CI：-0.47%，0.30%；P=0.66）。然而，那些被随机分配接受价格折扣的受试者在 6 个月时购买了明显更多的预先确定的更健康食品（多 11%；平均差异：0.79 公斤/周；95%CI：0.43，1.16；P<0.001）和 12 个月时（多 5%；平均差异：0.38 公斤/周；95%CI：0.01，0.76；P=0.045）。教育对食品购买没有影响。
价格折扣和定制营养教育都没有对购买的营养素产生显著影响。然而，折扣对食品购买的显著和持续影响表明，定价策略有望成为改善人群饮食的一种手段。
