The prospective impact of food pricing on improving dietary consumption: a systematic review and meta-analysis

Ashkan Afshin, Jose L. Penalvo, Liana Del Gobbo, Jose Silva, Melody Michaelson, Martin O'Flaherty, Simon Capewell, Donna Spiegelman, Goodarz Danaei, Dariush Mozaffarian

Research output: Contribution to journalA1: Web of Science-article

Abstract

Background

While food pricing is a promising strategy to improve diet, the prospective impact of food pricing on diet has not been systematically quantified.

Objective

To quantify the prospective effect of changes in food prices on dietary consumption.

Design

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 DerSimonianLaird'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.

Results

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/m(2) per 10% price decrease, 95% CI = -0.08-0 kg/m(2); 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

Conclusions

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.

Original languageEnglish
Article number0172277
JournalPLoS ONE
Volume12
Issue number3
Number of pages18
ISSN1932-6203
DOIs
Publication statusPublished - 2017

Keywords

  • LOW-INCOME POPULATION
  • PUBLIC-HEALTH
  • NUTRITION EDUCATION
  • VENDING MACHINES
  • PURCHASES
  • PRICES
  • FRUIT
  • INTERVENTION
  • WEIGHT
  • DISCOUNTS

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