Afshin Ashkan, Peñalvo José L, Del Gobbo Liana, Silva Jose, Michaelson Melody, O'Flaherty Martin, Capewell Simon, Spiegelman Donna, Danaei Goodarz, Mozaffarian Dariush
Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, United States of America.
Friedman School of Nutrition Science & Policy, Tufts University, Boston, MA, United States of America.
PLoS One. 2017 Mar 1;12(3):e0172277. doi: 10.1371/journal.pone.0172277. eCollection 2017.
While food pricing is a promising strategy to improve diet, the prospective impact of food pricing on diet has not been systematically quantified.
To quantify the prospective effect of changes in food prices on dietary consumption.
We systematically searched online databases for interventional or prospective observational studies of price change and diet; we also searched for studies evaluating adiposity as a secondary outcome. Studies were excluded if price data were collected before 1990. Data were extracted independently and in duplicate. Findings were pooled using DerSimonian-Laird's random effects model. Pre-specified sources of heterogeneity were analyzed using meta-regression; and potential for publication bias, by funnel plots, Begg's and Egger's tests.
From 3,163 identified abstracts, 23 interventional studies and 7 prospective cohorts with 37 intervention arms met inclusion criteria. In pooled analyses, a 10% decrease in price (i.e., subsidy) increased consumption of healthful foods by 12% (95%CI = 10-15%; N = 22 studies/intervention arms) whereas a 10% increase price (i.e. tax) decreased consumption of unhealthful foods by 6% (95%CI = 4-8%; N = 15). By food group, subsidies increased intake of fruits and vegetables by 14% (95%CI = 11-17%; N = 9); and other healthful foods, by 16% (95%CI = 10-23%; N = 10); without significant effects on more healthful beverages (-3%; 95%CI = -16-11%; N = 3). Each 10% price increase reduced sugar-sweetened beverage intake by 7% (95%CI = 3-10%; N = 5); fast foods, by 3% (95%CI = 1-5%; N = 3); and other unhealthful foods, by 9% (95%CI = 6-12%; N = 3). Changes in price of fruits and vegetables reduced body mass index (-0.04 kg/m2 per 10% price decrease, 95%CI = -0.08-0 kg/m2; N = 4); price changes for sugar-sweetened beverages or fast foods did not significantly alter body mass index, based on 4 studies. Meta-regression identified direction of price change (tax vs. subsidy), number of intervention components, intervention duration, and study quality score as significant sources of heterogeneity (P-heterogeneity<0.05 each). Evidence for publication bias was not observed.
These prospective results, largely from interventional studies, support efficacy of subsidies to increase consumption of healthful foods; and taxation to reduce intake of unhealthful beverages and foods. Use of subsidies and combined multicomponent interventions appear most effective.
虽然食品定价是改善饮食的一项有前景的策略，但食品定价对饮食的预期影响尚未得到系统量化。
量化食品价格变化对饮食消费的预期影响。
我们系统地在在线数据库中搜索关于价格变化与饮食的干预性或前瞻性观察性研究；我们还搜索了将肥胖作为次要结果进行评估的研究。如果价格数据是在1990年之前收集的，则排除该研究。数据由两人独立提取。使用DerSimonian-Laird随机效应模型汇总研究结果。使用元回归分析预先指定的异质性来源；通过漏斗图、Begg检验和Egger检验分析发表偏倚的可能性。
从3163篇已识别的摘要中，23项干预性研究和7个前瞻性队列（共37个干预组）符合纳入标准。在汇总分析中，价格降低10%（即补贴）使健康食品的消费量增加12%（95%置信区间 = 10 - 15%；N = 22项研究/干预组），而价格提高10%（即征税）使不健康食品的消费量减少6%（95%置信区间 = 4 - 8%；N = 15）。按食物类别划分，补贴使水果和蔬菜的摄入量增加14%（95%置信区间 = 11 - 17%；N = 9）；其他健康食品的摄入量增加16%（95%置信区间 = 10 - 23%；N = 10）；对更健康的饮料没有显著影响（-3%；95%置信区间 = -16 - 11%；N = 3）。价格每提高10%，含糖饮料的摄入量减少7%（95%置信区间 = 3 - 10%；N = 5）；快餐的摄入量减少3%（95%置信区间 = 1 - 5%；N = 3）；其他不健康食品的摄入量减少9%（95%置信区间 = 6 - 12%；N = 3）。水果和蔬菜价格的变化使体重指数降低（每价格降低10%，体重指数降低0.04 kg/m²，95%置信区间 = -0.08 - 0 kg/m²；N = 4）；基于4项研究，含糖饮料或快餐价格的变化未显著改变体重指数。元回归确定价格变化方向（征税与补贴）、干预组成部分数量、干预持续时间和研究质量得分是异质性的显著来源（每个P - 异质性<0.05）。未观察到发表偏倚的证据。
这些主要来自干预性研究的前瞻性结果支持补贴增加健康食品消费以及征税减少不健康饮料和食品摄入的有效性。补贴和多成分联合干预似乎最有效。
