Abstract P062: The Effect of Food Pricing on Dietary Behaviors and Adiposity: a Systematic Review and Meta-analysis

Abstract

Background: While food pricing is a promising strategy to improve diet and reduce cardiometabolic disease, most prior evidence comes from cross-sectional price elasticity estimates. The prospective impact of food pricing on dietary behaviors and obesity has not been systematically evaluated. Objective: To systematically investigate and quantify the effect of price change on dietary intake and on adiposity, as well as whether other underlying factors alter these effects. Methods: Using MOOSE and PRISMA guidelines, we systematically searched PubMed, Embase, EconLit, OVID, Cochrane library, Web of Knowledge, and CINHAL for prospective observational or interventional studies of price differences and diet (foods, drinks, energy) or adiposity. Studies were excluded if cross-sectional; price data collected before 1990; or reporting only crude risk estimates. Data were extracted independently and in duplicate. Findings were pooled using inverse-variance meta-analysis Results: From 2,299 identified abstracts, 21 met inclusions. These included 6 randomized trials and 7 quasi-experimental studies in different settings (supermarket, school/workplace cafeteria, restaurant) in 3 countries (US, New Zealand, Netherland); and 8 observational studies mostly using nationally representative US data. Studies evaluated effects of increase (n=10, 1-35% increase) in price (fast food, energy dense snacks, soda) and decrease (n=11, 10-50% decrease) in price (fruits, vegetables, low fat/calorie products) among adults (n=13) and children (n=8). Studies consistently showed that price increases led to decreased consumption; effects of price decreases on consumption and price increases/decreases on BMI were less consistent. A mean $0.43/serving (12 oz) increase in price of soda was associated with 2.77 servings/wk lower consumption (95% CI: 1.58. 3.96, n=4 studies). A mean %30/serving decrease in price of fruits and vegetables was not significantly associated with consumption (+536 g/d, 95% CI: -427, 1500, n=2 studies). High between study heterogeneity was evident for price increase and soda intake and price discount and fruit intake. Conclusions: These prospective results support taxation to reduce soda intake. More evidence from prospective studies and trials is needed on food pricing and other dietary outcomes and adiposity.