Food prices and obesity: evidence and policy implications for taxes and subsidies

Best practices in policy approaches to obesity prevention

The rapidly rising rate of obesity has prompted a variety of policy responses at national, regional, and local levels. Yet, many have expressed concern that these policy responses have a limited evidence base, are overly paternalistic, and have the potential to increase rather than shrink obesity-related disparities. The purpose of this article is to evaluate obesity policies in terms of the adequacy of evidence for action and along two ethical dimensions: their potential effect on liberty and equity. To evaluate evidence, we engage in a systematic review of reviews and rate policies in terms of the sufficiency of evidence of effectiveness at combating obesity. We then apply a libertarian-paternalist framework to assess policies in terms of their impact on liberty and inverse-equity theory to assess impact on disparities. This article provides a framework to assist decision-makers in assessing best practices in obesity using a more multi-faceted set of dimensions.

Choosing healthier foods in recreational sports settings: a mixed methods investigation of the impact of nudging and an economic incentive

BACKGROUND

Nudging is an approach to environmental change that alters social and physical environments to shift behaviors in positive, self-interested directions. Evidence indicates that eating is largely an automatic behavior governed by environmental cues, suggesting that it might be possible to nudge healthier dietary behaviors. This study assessed the comparative and additive efficacy of two nudges and an economic incentive in supporting healthy food purchases by patrons at a recreational swimming pool.

METHODS

An initial pre-intervention period was followed by three successive and additive interventions that promoted sales of healthy items through: signage, taste testing, and 30% price reductions; concluding with a return to baseline conditions. Each period was 8 days in length. The primary outcome was the change in the proportion of healthy items sold in the intervention periods relative to pre- and post-intervention in the full sample, and in a subsample of patrons whose purchases were directly observed. Secondary outcomes included change in the caloric value of purchases, change in revenues and gross profits, and qualitative process observations. Data were analyzed using analysis of covariance, chi-square tests and thematic content analysis.

RESULTS

Healthy items represented 41% of sales and were significantly lower than sales of unhealthy items (p < 0.0001). In the full sample, sales of healthy items did not differ across periods, whereas in the subsample, sales of healthy items increased by 30% when a signage + taste testing intervention was implemented (p < 0.01). This increase was maintained when prices of healthy items were reduced by 30%, and when all interventions were removed. When adults were alone they purchased more healthy items compared to when children were present during food purchases (p < 0.001), however parental choices were not substantially better than choices made by children alone.

CONCLUSIONS

This study found mixed evidence for the efficacy of nudging in cueing healthier dietary behaviors. Moreover, price reductions appeared ineffectual in this setting. Our findings point to complex, context-specific patterns of effectiveness and suggest that nudging should not supplant the use of other strategies that have proven to promote healthier dietary behaviors.

Food prices and body fatness among youths

We examine the effect of food prices on clinical measures of obesity, including body mass index (BMI) and percentage body fat (PBF) measures derived from bioelectrical impedance analysis (BIA) and dual energy X-ray absorptiometry (DXA), among youths ages 12 through 18 in the National Health and Nutrition Examination Survey. This is the first study to consider clinically measured levels of body composition rather than BMI to investigate the effects of food prices on obesity outcomes among youths classified by gender and race/ethnicity. Our findings suggest that increases in the real price per calorie of food for home consumption and the real price of fast-food restaurant food lead to improvements in obesity outcomes among youths. We also find that a rise in the real price of fruits and vegetables leads to increased obesity. Finally, our results indicate that measures of PBF derived from BIA and DXA are no less sensitive and in some cases more sensitive to the prices just mentioned than BMI, and serve an important role in demonstrating that rising food prices (except fruit and vegetable prices) are indeed associated with reductions in obesity rather than with reductions in body size proportions alone.

Evaluating the initial impact of the revised Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) food packages on dietary intake and home food availability in African-American and Hispanic families

OBJECTIVE

The present study assessed the impact of the 2009 food packages mandated by the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) on dietary intake and home food availability in low-income African-American and Hispanic parent/child dyads.

DESIGN

A natural experiment was conducted to assess if the revised WIC food package altered dietary intake, home food availability, weight and various lifestyle measures immediately (6 months) following policy implementation.

SETTING

Twelve WIC clinics in Chicago, IL, USA.

SUBJECTS

Two hundred and seventy-three Hispanic and African-American children aged 2-3 years, enrolled in WIC, and their mothers.

RESULTS

Six months after the WIC food package revisions were implemented, we observed modest changes in dietary intake. Fruit consumption increased among Hispanic mothers (mean = 0·33 servings/d, P = 0·04) and low-fat dairy intake increased among Hispanic mothers (0·21 servings/d, P = 0·02), Hispanic children (0·34 servings/d, P < 0·001) and African-American children (0·24 servings/d, P = 0·02). Home food availability of low-fat dairy and whole grains also increased. Dietary changes, however, varied by racial/ethnic group. Changes in home food availability were not significantly correlated with changes in diet.

CONCLUSIONS

The WIC food package revisions are one of the first efforts to modify the nutrition guidelines that govern foods provided in a federal food and nutrition assistance programme. It will be important to examine the longer-term impact of these changes on dietary intake and weight status.

Averting obesity and type 2 diabetes in India through sugar-sweetened beverage taxation: an economic-epidemiologic modeling study

BACKGROUND

Taxing sugar-sweetened beverages (SSBs) has been proposed in high-income countries to reduce obesity and type 2 diabetes. We sought to estimate the potential health effects of such a fiscal strategy in the middle-income country of India, where there is heterogeneity in SSB consumption, patterns of substitution between SSBs and other beverages after tax increases, and vast differences in chronic disease risk within the population.

METHODS AND FINDINGS

Using consumption and price variations data from a nationally representative survey of 100,855 Indian households, we first calculated how changes in SSB price alter per capita consumption of SSBs and substitution with other beverages. We then incorporated SSB sales trends, body mass index (BMI), and diabetes incidence data stratified by age, sex, income, and urban/rural residence into a validated microsimulation of caloric consumption, glycemic load, overweight/obesity prevalence, and type 2 diabetes incidence among Indian subpopulations facing a 20% SSB excise tax. The 20% SSB tax was anticipated to reduce overweight and obesity prevalence by 3.0% (95% CI 1.6%-5.9%) and type 2 diabetes incidence by 1.6% (95% CI 1.2%-1.9%) among various Indian subpopulations over the period 2014-2023, if SSB consumption continued to increase linearly in accordance with secular trends. However, acceleration in SSB consumption trends consistent with industry marketing models would be expected to increase the impact efficacy of taxation, averting 4.2% of prevalent overweight/obesity (95% CI 2.5-10.0%) and 2.5% (95% CI 1.0-2.8%) of incident type 2 diabetes from 2014-2023. Given current consumption and BMI distributions, our results suggest the largest relative effect would be expected among young rural men, refuting our a priori hypothesis that urban populations would be isolated beneficiaries of SSB taxation. Key limitations of this estimation approach include the assumption that consumer expenditure behavior from prior years, captured in price elasticities, will reflect future behavior among consumers, and potential underreporting of consumption in dietary recall data used to inform our calculations.

CONCLUSION

Sustained SSB taxation at a high tax rate could mitigate rising obesity and type 2 diabetes in India among both urban and rural subpopulations.

Obesity persistence and duration dependence: evidence from a cohort of US adults (1985-2010)

This study investigates dynamic patterns of obesity persistence and identifies the determinants of obesity-spell exits and re-entries. We utilize longitudinal data from the NLSY79 covering the period 1985-2010. Non-parametric techniques are applied to investigate the relationship between exit from obesity and spell duration. Multivariate discrete hazard models are also estimated, taking into account duration dependence and observed and time-invariant unobserved heterogeneity. In all cases, the probability of exiting obesity is inversely related to the duration of the obesity spell. Without controlling for unobserved heterogeneity, the probability of exit after one wave in obesity is 31.5 per cent; it is reduced to 3.8 per cent after seven or more waves. When time-invariant unobserved heterogeneity is taken into account, the estimated probabilities are slightly larger and broadly similar (36.8 and 10.3, respectively), which suggests that the identified negative duration dependence is not primarily due to composition effects. The obtained results indicate that public health interventions targeting the newly obese may be particularly effective at reducing incidence of long durations of obesity.

Nutritional impacts of a fruit and vegetable subsidy programme for disadvantaged Australian Aboriginal children

Healthy food subsidy programmes have not been widely implemented in high-income countries apart from the USA and the UK. There is, however, interest being expressed in the potential of healthy food subsidies to complement nutrition promotion initiatives and reduce the social disparities in healthy eating. Herein, we describe the impact of a fruit and vegetable (F&V) subsidy programme on the nutritional status of a cohort of disadvantaged Aboriginal children living in rural Australia. A before-and-after study was used to assess the nutritional impact in 174 children whose families received weekly boxes of subsidised F&V organised through three Aboriginal medical services. The nutritional impact was assessed by comparing 24 h dietary recalls and plasma carotenoid and vitamin C levels at baseline and after 12 months. A general linear model was used to assess the changes in biomarker levels and dietary intake, controlled for age, sex, community and baseline levels. Baseline assessment in 149 children showed low F&V consumption. Significant increases (P< 0.05) in β-cryptoxanthin (28.9 nmol/l, 18%), vitamin C (10.1 μmol/l, 21%) and lutein-zeaxanthin (39.3 nmol/l, 11%) levels were observed at the 12-month follow-up in 115 children, although the self-reported F&V intake was unchanged. The improvements in the levels of biomarkers of F&V intake demonstrated in the present study are consistent with increased F&V intake. Such dietary improvements, if sustained, could reduce non-communicable disease rates. A controlled study of healthy food subsidies, together with an economic analysis, would facilitate a thorough assessment of the costs and benefits of subsidising healthy foods for disadvantaged Aboriginal Australians.

Evidence that a tax on sugar sweetened beverages reduces the obesity rate: a meta-analysis

BACKGROUND

Excess intake of sugar sweetened beverages (SSBs) has been shown to result in weight gain. To address the growing epidemic of obesity, one option is to combine programmes that target individual behaviour change with a fiscal policy such as excise tax on SSBs. This study evaluates the literature on SSB taxes or price increases, and their potential impact on consumption levels, obesity, overweight and body mass index (BMI). The possibility of switching to alternative drinks is also considered.

METHODS

The following databases were used: Pubmed/Medline, The Cochrane Database of Systematic Reviews, Google Scholar, Econlit, National Bureau of Economics Research (NBER), Research Papers in Economics (RePEc). Articles published between January 2000 and January 2013, which reported changes in diet or BMI, overweight and/or obesity due to a tax on, or price change of, SSBs were included.

RESULTS

Nine articles met the criteria for the meta-analysis. Six were from the USA and one each from Mexico, Brazil and France. All showed negative own-price elasticity, which means that higher prices are associated with a lower demand for SSBs. Pooled own price-elasticity was -1.299 (95% CI: -1.089 - -1.509). Four articles reported cross-price elasticities, three from the USA and one from Mexico; higher prices for SSBs were associated with an increased demand for alternative beverages such as fruit juice (0.388, 95% CI: 0.009 - 0.767) and milk (0.129, 95% CI: -0.085 - 0.342), and a reduced demand for diet drinks (-0.423, 95% CI: -0.628 - -1.219). Six articles from the USA showed that a higher price could also lead to a decrease in BMI, and decrease the prevalence of overweight and obesity.

CONCLUSIONS

Taxing SSBs may reduce obesity. Future research should estimate price elasticities in low- and middle-income countries and identify potential health gains and the wider impact on jobs, monetary savings to the health sector, implementation costs and government revenue. Context-specific cost-effectiveness studies would allow policy makers to weigh these factors.

Development and reliability testing of a food store observation form

OBJECTIVE

To develop a reliable food store observational data collection instrument to be used for measuring product availability, pricing, and promotion.

DESIGN

Observational data collection.

SETTING

A total of 120 food stores (26 supermarkets, 34 grocery stores, 54 gas/convenience stores, and 6 mass merchandise stores) in the Chicago metropolitan statistical area.

MAIN OUTCOME MEASURES

Inter-rater reliability for product availability, pricing, and promotion measures on a food store observational data collection instrument.

ANALYSIS

Cohen's kappa coefficient and proportion of overall agreement for dichotomous variables and intra-class correlation coefficient for continuous variables.

RESULTS

Inter-rater reliability, as measured by average kappa coefficient, was 0.84 for food and beverage product availability measures, 0.80 for interior store characteristics, and 0.70 for exterior store characteristics. For continuous measures, average intra-class correlation coefficient was 0.82 for product pricing measures; 0.90 for counts of fresh, frozen, and canned fruit and vegetable options; and 0.85 for counts of advertisements on the store exterior and property.

CONCLUSIONS AND IMPLICATIONS

The vast majority of measures demonstrated substantial or almost perfect agreement. Although some items may require revision, results suggest that the instrument may be used to reliably measure the food store environment.

Access to nutritious food, socioeconomic individualism and public health ethics in the USA: a common good approach

Good nutrition plays an important role in the optimal growth, development, health and well-being of individuals in all stages of life. Healthy eating can reduce the risk of chronic diseases, such as heart disease, stroke, diabetes and some types of cancer. However, the capitalist mindset that shapes the food environment has led to the commoditization of food. Food is not just a marketable commodity like any other commodity. Food is different from other commodities on the market in that it is explicitly and intrinsically linked to our human existence. While possessing another commodity allows for social benefits, food ensures survival. Millions of people in United States of America are either malnourished or food insecure. The purpose of this paper is to present a critique of the current food system using four meanings of the common good--as a framework, rhetorical device, ethical concept and practical tool for social justice. The first section of this paper provides a general overview of the notion of the common good. The second section outlines how each of the four meanings of the common good helps us understand public practices, social policies and market values that shape the distal causal factors of nutritious food inaccessibility. We then outline policy and empowerment initiatives for nutritious food access.

A systematic review of the effectiveness of taxes on nonalcoholic beverages and high-in-fat foods as a means to prevent obesity trends

BACKGROUND

As part of the efforts to curb obesity, a new focus seems to be put on taxing foods that are perceived as being associated with obesity (eg, sugar-sweetened beverages and foods high in fat, sugar, and salt content) as a policy instrument to promote healthier diets.

OBJECTIVE

To assess the possible effects of such taxation policies by identifying and analyzing all studies which investigate the impact of price increases on consumption, caloric intake, or weight outcomes.

METHODS

Electronic data bases were searched with appropriate terms and their combinations. Thereafter, abstracts were reviewed and studies were selected based on predefined criteria. The characteristics of the selected studies and the results were extracted in a special form and consequently were reviewed and synthesized.

RESULTS

Price increase may lead to a reduction in consumption of the targeted products, but the subsequent effect on caloric intake may be much smaller. Only a limited number of the identified studies reported weight outcomes, most of which are either insignificant or very small in magnitude to make any improvement in public health.

CONCLUSION

The effectiveness of a taxation policy to curb obesity is doubtful and available evidence in most studies is not very straightforward due to the multiple complexities in consumer behavior and the underling substitution effects. There is need to investigate in-depth the potential underlying mechanisms and the relationship between price-increase policies, obesity, and public health outcomes.

Food prices and consumer demand: differences across income levels and ethnic groups

Background

Targeted food pricing policies may improve population diets. To assess their effects on inequalities, it is important to determine responsiveness to price changes across income levels and ethnic groups.

Objective

Our goal was to estimate price elasticity (PE) values for major commonly consumed food groups in New Zealand, by income and ethnicity. PE values represent percentage change in demand associated with 1% change in price of that good (own-PE) or another good (cross-PE).

Design

We used food expenditure data from national household economic surveys in 2007/08 and 2009/10 and Food Price Index data from 2007 and 2010. Adopting an Almost Ideal Demand System approach, own-PE and cross-PE estimates were derived for 24 food categories, household income quintiles, and two ethnic groups (Māori and non-Māori).

Results

Own-PE estimates (with two exceptions) ranged from −0.44 to −1.78. Cross-PE estimates were generally small; only 31% of absolute values were greater than 0.10. Excluding the outlier ‘energy drinks’, nine of 23 food groups had significantly stronger own-PEs for the lowest versus highest income quintiles (average regression-based difference across food groups −0.30 (95% CI −0.62 to 0.02)). Six own-PEs were significantly stronger among Māori; the average difference for Māori: non-Māori across food groups was −0.26 (95% CI −0.52 to 0.00).

Conclusions

Food pricing policies have potential to improve population diets. The greater sensitivity of low-income households and Māori to price changes suggests the beneficial effects of such policies on health would be greatest for these groups.

Monitoring the price and affordability of foods and diets globally

Food prices and food affordability are important determinants of food choices, obesity and non-communicable diseases. As governments around the world consider policies to promote the consumption of healthier foods, data on the relative price and affordability of foods, with a particular focus on the difference between 'less healthy' and 'healthy' foods and diets, are urgently needed. This paper briefly reviews past and current approaches to monitoring food prices, and identifies key issues affecting the development of practical tools and methods for food price data collection, analysis and reporting. A step-wise monitoring framework, including measurement indicators, is proposed. 'Minimal' data collection will assess the differential price of 'healthy' and 'less healthy' foods; 'expanded' monitoring will assess the differential price of 'healthy' and 'less healthy' diets; and the 'optimal' approach will also monitor food affordability, by taking into account household income. The monitoring of the price and affordability of 'healthy' and 'less healthy' foods and diets globally will provide robust data and benchmarks to inform economic and fiscal policy responses. Given the range of methodological, cultural and logistical challenges in this area, it is imperative that all aspects of the proposed monitoring framework are tested rigorously before implementation.

The potential impact on obesity of a 10% tax on sugar-sweetened beverages in Ireland, an effect assessment modelling study

BACKGROUND

Some governments have recently shown a willingness to introduce taxes on unhealthy foods and drinks. In 2011, the Irish Minister for Health proposed a 10% tax on sugar sweetened beverages (SSBs) as a measure to combat childhood obesity. Whilst this proposed tax received considerable support, the Irish Department of Finance requested a Health Impact Assessment of this measure. As part of this assessment we set out to model the impact on obesity.

METHODS

We used price elasticity estimates to calculate the effect of a 10% SSB tax on SSB consumption. SSBs were assumed to have an own-price elasticity of -0.9 and we assumed a tax pass-on rate to consumers of 90%. Baseline SSB consumption and obesity prevalence, by age, sex and income-group, for Ireland were taken from the 2007 Survey on Lifestyle and Attitude to Nutrition. A comparative risk assessment model was used to estimate the effect on obesity arising from the predicted change in calorie consumption, both for the whole population and for sub-groups (age, sex, income). Sensitivity analyses were conducted on price-elasticity estimates and tax pass-on rates.

RESULTS

We estimate that a 10% tax on SSBs will result in a mean reduction in energy intake of 2.1 kcal/person/day. After adjustment for self-reported data, the 10% tax is predicted to reduce the percentage of the obese adult population (body mass index [BMI] ≥ 30 kg/m(2)) by 1.3%, equating to 9,900 adults (95% credible intervals: 7,750 to 12,940), and the overweight or obese population (BMI ≥ 25 kg/m(2)) by 0.7%, or 14,380 adults (9,790 to 17,820). Reductions in obesity are similar for men (1.2%) and women (1.3%), and similar for each income group (between 1.1% and 1.4% across income groups). Reductions in obesity are greater in young adults than older adults (e.g. 2.9% in adults aged 18-24 years vs 0.6% in adults aged 65 years and over).

CONCLUSIONS

This study suggests that a tax on SSBs in Ireland would have a small but meaningful effect on obesity. While such a tax would be perceived as affecting the whole population, from a health prospective the tax will predominantly affect younger adults who are the main consumers of SSBs.

Understanding price elasticities to inform public health research and intervention studies: key issues

Pricing policies such as taxes and subsidies are important tools in preventing and controlling a range of threats to public health. This is particularly so in tobacco and alcohol control efforts and efforts to change dietary patterns and physical activity levels as a means of addressing increases in noncommunicable diseases. To understand the potential impact of pricing policies, it is critical to understand the nature of price elasticities for consumer products. For example, price elasticities are key parameters in models of any food tax or subsidy that aims to quantify health impacts and cost-effectiveness. We detail relevant terms and discuss key issues surrounding price elasticities to inform public health research and intervention studies.

Taxing junk food to counter obesity

We examined the advantages and disadvantages of implementing a junk food tax as an intervention to counter increasing obesity in North America. Small excise taxes are likely to yield substantial revenue but are unlikely to affect obesity rates. High excise taxes are likely to have a direct impact on weight in at-risk populations but are less likely to be politically palatable or sustainable. Ultimately, the effectiveness of earmarked health programs and subsidies is likely to be a key determinant of tax success in the fight against obesity.

Changes in anthropometric measurements, body composition, blood pressure, lipid profile, and testosterone in patients participating in a low-energy dietary intervention

OBJECTIVE

The purpose of this study was to describe changes in anthropometric measurements, body composition, blood pressure, lipid profile, and testosterone following a low-energy-density dietary intervention plus regimented supplementation program.

METHODS

The study design was a pre-post intervention design without a control group. Normal participants were recruited from the faculty, staff, students, and community members from a chiropractic college to participate in a 21-day weight loss program. All participants (n = 49; 36 women, 13 men; 31 ± 10.3 years of age) received freshly prepared mostly vegan meals (breakfast, lunch, and dinner) that included 1200 to 1400 daily calories (5020.8 to 5857.6 J) for the women and 1600 to 1800 (6694.4 to 7531.2 J) daily calories for the men. Nutritional supplements containing enzymes that were intended to facilitate digestion, reduce cholesterol levels, increase metabolic rate, and mediate inflammatory processes were consumed 30 minutes before each meal. The regimented supplementation program included once-daily supplementation with a green drink that contained alfalfa, wheatgrass, apple cider vinegar, and fulvic acid throughout the study period. A cleanse supplementation containing magnesium, chia, flaxseed, lemon, camu camu, cat's claw, bentonite clay, tumeric, pau d'arco, chanca piedra, stevia, zeolite clay, slippery elm, garlic, ginger, peppermint, aloe, citrus bioflavonoids, and fulvic acid was added before each meal during week 2. During week 3, the cleanse supplementation was replaced with probiotic and prebiotic supplementation.

RESULTS

Multiple paired t tests detected clinically meaningful reductions in weight (- 8.7 ± 5.54 lb) (- 3.9 ± 2.5 kg), total cholesterol (- 30.0 ± 29.77 mg/dL), and low-density lipoprotein cholesterol (- 21.0 ± 25.20 mg/dL) (P < .05). There was a pre-post intervention increase in testosterone for men (111.0 ± 121.13 ng/dL, P < .05).

CONCLUSIONS

Weight loss and improvements in total cholesterol and low-density lipoprotein cholesterol levels occurred after a low-energy-density dietary intervention plus regimented supplementation program.

Neighborhood socioeconomic characteristics and differences in the availability of healthy food stores and restaurants in Sao Paulo, Brazil

Differential access to healthy foods has been hypothesized to contribute to health disparities, but evidence from low and middle-income countries is still scarce. This study examines whether the access of healthy foods varies across store types and neighborhoods of different socioeconomic statuses (SES) in a large Brazilian city. A cross-sectional study was conducted in 2010-2011 across 52 census tracts. Healthy food access was measured by a comprehensive in-store data collection, summarized into two indexes developed for retail food stores (HFSI) and restaurants (HMRI). Descriptive analyses and multilevel models were used to examine associations of store type and neighborhood SES with healthy food access. Fast food restaurants were more likely to be located in low SES neighborhoods whereas supermarkets and full service restaurants were more likely to be found in higher SES neighborhoods. Multilevel analyses showed that both store type and neighborhood SES were independently associated with in-store food measures. We found differences in the availability of healthy food stores and restaurants in Sao Paulo city favoring middle and high SES neighborhoods.

Food mirages: geographic and economic barriers to healthful food access in Portland, Oregon

This paper investigated the role of grocery store prices in structuring food access for low-income households in Portland, Oregon. We conducted a detailed healthful foods market basket survey and developed an index of store cost based on the USDA Thrifty Food Plan. Using this index, we estimated the difference in street-network distance between the nearest low-cost grocery store and the nearest grocery store irrespective of cost. Spatial regression of this metric in relation to income, poverty, and gentrification at the census tract scale lead to a new theory regarding food access in the urban landscape. Food deserts are sparse in Portland, but food mirages are abundant, particularly in gentrifying areas where poverty remains high. In a food mirage, grocery stores are plentiful but prices are beyond the means of low-income households, making them functionally equivalent to food deserts in that a long journey to obtain affordable, nutritious food is required in either case. Results suggested that evaluation of food environments should, at a minimum, consider both proximity and price in assessing healthy food access for low-income households.

Association of supermarket characteristics with the body mass index of their shoppers

BACKGROUND

Research on the built food environment and weight status has mostly focused on the presence/absence of food outlets while ignoring their internal features or where residents actually shop. We explored associations of distance travelled to supermarkets and supermarket characteristics with shoppers' body mass index (BMI).

METHODS

Shoppers (n=555) of five supermarkets situated in different income areas in the city were surveyed for food shopping habits, demographics, home postal code, height and weight. Associations of minimum distance to a supermarket (along road network, objectively measured using ArcGIS), its size, food variety and food basket price with shoppers' BMI were investigated. The 'food basket' was defined as the mixture of several food items commonly consumed by residents and available in all supermarkets.

RESULTS

Supermarkets ranged in total floor space (7500-135,000 square feet) and had similar varieties of fruits, vegetables and cereals. The majority of participants shopped at the surveyed supermarket more than once per week (mean range 1.2 ± 0.8 to 2.3 ± 2.1 times per week across the five supermarkets, p < 0.001), and identified it as their primary store for food (52% overall). Mean participant BMI of the five supermarkets ranged from 23.7 ± 4.3 kg/m² to 27.1 ± 4.3 kg/m² (p < 0.001). Median minimum distance from the shoppers' residence to the supermarket they shopped at ranged from 0.96 (0.57, 2.31) km to 4.30 (2.83, 5.75) km (p < 0.001). A negative association was found between food basket price and BMI. There were no associations between BMI and minimum distance to the supermarket, or other supermarket characteristics. After adjusting for age, sex, dissemination area median individual income and car ownership, BMI of individuals who shopped at Store 1 and Store 2, the supermarkets with lowest price of the 'food basket', was 3.66 kg/m² and 3.73 kg/m² higher compared to their counterparts who shopped at the supermarket where the 'food basket' price was highest (p < 0.001).

CONCLUSIONS

The food basket price in supermarkets was inversely associated with BMI of their shoppers. Our results suggest that careful manipulation of food prices may be used as an intervention for decreasing BMI.

Promotion of healthy eating through public policy: a controlled experiment

BACKGROUND

To induce consumers to purchase healthier foods and beverages, some policymakers have suggested special taxes or labels on unhealthy products. The potential of such policies is unknown.

PURPOSE

In a controlled field experiment, researchers tested whether consumers were more likely to purchase healthy products under such policies.

METHODS

From October to December 2011, researchers opened a store at a large hospital that sold a variety of healthier and less-healthy foods and beverages. Purchases (N=3680) were analyzed under five conditions: a baseline with no special labeling or taxation, a 30% tax, highlighting the phrase "less healthy" on the price tag, and combinations of taxation and labeling. Purchases were analyzed in January-July 2012, at the single-item and transaction levels.

RESULTS

There was no significant difference between the various taxation conditions. Consumers were 11 percentage points more likely to purchase a healthier item under a 30% tax (95% CI=7%, 16%, p<0.001) and 6 percentage points more likely under labeling (95% CI=0%, 12%, p=0.04). By product type, consumers switched away from the purchase of less-healthy food under taxation (9 percentage point decrease, p<0.001) and into healthier beverages (6 percentage point increase, p=0.001); there were no effects for labeling. Conditions were associated with the purchase of 11-14 fewer calories (9%-11% in relative terms) and 2 fewer grams of sugar. Results remained significant controlling for all items purchased in a single transaction.

CONCLUSIONS

Taxation may induce consumers to purchase healthier foods and beverages. However, it is unclear whether the 15%-20% tax rates proposed in public policy discussions would be more effective than labeling products as less healthy.

Food purchasing selection among low-income, Spanish-speaking Latinos

BACKGROUND

In the U.S., poverty has been linked to both obesity and disease burden. Latinos in the U.S. are disproportionately affected by poverty, and over the past 10 years, the percentage of overweight U.S. Latino youth has approximately doubled. Buying low-cost food that is calorie-dense and filling has been linked to obesity. Low-income individuals tend to favor energy-dense foods because of their low cost, and economic decisions made during food purchasing have physiologic repercussions. Diets based on energy-dense foods tend to be high in processed staples, such as refined grains, added sugars, and added fats. These diets have been linked to a higher risk of obesity, type 2 diabetes, and cardiovascular disease.

PURPOSE

This pilot study conducted ethnographic qualitative analyses combined with quantitative analyses to understand grocery shopping practices among 20 Spanish-speaking, low-income Latino families. The purpose was to analyze food selection practices in order to determine the effect of nutrition education on changes in shopping practices to later develop educational tools to promote selection of healthier food options.

METHODS

Participants received tailored, interactive, nutrition education during three to five home visits and a supermarket tour. Grocery store receipts for grocery purchases collected at baseline and at the end of the project were analyzed for each family to extract nutritional content of purchased foods. Nutritional content was measured with these factors in mind: quantity, calories, fats, carbohydrates, fiber, protein, and percentage of sugary beverages and processed food. Data were collected in 2010-2011 and analyzed in 2011-2012.

RESULTS

After receiving between three and five home-based nutrition education sessions and a supermarket tour over a 6-month period, many families adopted instructions on buying budget-friendly, healthier alternative foods. Findings indicate that participating families decreased the total number of calories and calories per dollar purchased from baseline to post-education (median total calories: baseline, 20,191; post-education, 15,991, p=0.008); median calories per dollar: baseline, 404; post-education, 320, p=0.008). The median grams of carbohydrates per dollar (baseline, 66, post-education, 45) and median calories from processed food (baseline, 11,000, post-education, 7845) were not reduced (p=0.06).

CONCLUSIONS

This pilot study demonstrated that grocery shopping practices are an important factor to address in nutrition education among Spanish-speaking, low-income individuals, and that there may be ways to encourage low-income, Latino families to purchase healthier foods. Findings challenged arguments suggesting that such an approach is not possible because of the high cost of healthier foods.

Simulation modeling of policies directed at youth sugar-sweetened beverage consumption

Childhood obesity is a significant public health problem requiring innovative solutions. While recent reviews indicate that some policies show promise, there is a lack of information regarding which policies, and policy combinations, work best. Low-nutrition, energy-dense foods and beverages such as sugar-sweetened beverages (SSBs) have been identified as a major contributor to the problem. The purpose of this paper is to use simulation modeling to show how changes in three categories of SSB policies-school nutrition, school-based education, and taxes-impact SSB and other food consumption. The model shows that policies directed at SSBs, particularly tax hikes, could lead to substantial reductions in the number of calories consumed by youth. The estimates, however, are subject to a high degree of uncertainty. Estimates from school-based nutrition and school-based education policies, while also helping to reduce caloric intake, generally show smaller effects than tax policies and considerable variation around parameter estimates for individual and combined policies. We conclude with a discussion of the limits of the model, and suggest where additional information is needed. Limitations notwithstanding, simulation modeling is a promising methodology that can help advance our understanding of policy effects, thereby helping policymakers to better formulate effective policies to reduce obesity prevalence and the associated social harms.

Prices of healthy and unhealthy beverages in high and low per capita income areas

To better understand availability and price of beverages in Hawai'i, the prices of healthy (milk, orange juice, unsweetened tea, unsweetened coffee, diet soda) and unhealthy beverages (regular soda, fruit drink, sports drink, sweetened tea, flavored water) were collected and the beverage prices in lower per capita income areas and higher per capita income areas were compared. Cross-sectional data on prices of healthy and unhealthy beverages were collected from supermarkets, convenience stores, and quick serve restaurants from two lower per capita income areas (Waimanalo and Wai'anae) and two higher per capita income areas (Hawai'i Kai and Manoa) on O'ahu, Hawai'i from May 15 to June 10, 2012. Using composite data from across all areas, there was a significant difference of $0.58 (95% CI 0.46, 0.70) between the healthy beverages' mean price per 20 ounces ($1.76 ± $0.86) and the unhealthy beverages' mean price per 20 ounces ($1.18 ± $0.38) (P <.001). Although there was no statistically significant difference between per capita income areas, the lower per capita income areas' mean price per 20 ounces of healthy beverages was slightly higher and mean price per 20 ounces of unhealthy beverages was slightly lower than the higher per capita income areas. Pricing strategies that enable healthy beverages to be less expensive than unhealthy beverages is one method to increase consumption of healthy beverages and decrease consumption of unhealthy beverages. Reduction in unhealthy beverage consumption is needed to help reduce obesity, especially in the lower per capita income areas that have higher obesity prevalence.

Food prices and overweight patterns in Italy

In this paper, we examine the role of relative food prices in determining the recent increase in body weight in Italy. Cross-price elasticities of unhealthy and healthy foods estimated by a demand system provide a consistent framework to evaluate substitution effects, when a close association is assumed between unhealthy (healthy) foods and more (less) energy-dense foods. We used a dataset constructed from a series of cross-sections of the Italian Household Budget Survey (1997-2005) to obtain the variables of the demand system, which accounts for regional price variability. The relative increase in healthy food prices was found to produce nontrivial elasticities of substitution towards higher relative consumption of unhealthy foods, with effects on weight outcomes. In addition, these changes were unevenly distributed among individuals and were particularly significant for those who were poorer and had less education.

Assessing the potential effectiveness of food and beverage taxes and subsidies for improving public health: a systematic review of prices, demand and body weight outcomes

Taxes and subsidies are increasingly being considered as potential policy instruments to incentivize consumers to improve their food and beverage consumption patterns and related health outcomes. This study provided a systematic review of recent U.S. studies on the price elasticity of demand for sugar-sweetened beverages (SSBs), fast food, and fruits and vegetables, as well as the direct associations of prices/taxes with body weight outcomes. Based on the recent literature, the price elasticity of demand for SSBs, fast food, fruits and vegetables was estimated to be -1.21, -0.52, -0.49 and -0.48, respectively. The studies that linked soda taxes to weight outcomes showed minimal impacts on weight; however, they were based on existing state-level sales taxes that were relatively low. Higher fast-food prices were associated with lower weight outcomes particularly among adolescents, suggesting that raising prices would potentially impact weight outcomes. Lower fruit and vegetable prices were generally found to be associated with lower body weight outcomes among both low-income children and adults, suggesting that subsidies that would reduce the cost of fruits and vegetables for lower-socioeconomic populations may be effective in reducing obesity. Pricing instruments should continue to be considered and evaluated as potential policy instruments to address public health risks.

Taxes on sugar-sweetened beverages: results from a 2011 national public opinion survey

BACKGROUND

Consumption of sugar-sweetened beverages including nondiet sodas, sport drinks, and energy drinks has been linked with obesity. Recent state and local efforts to tax these beverages have been unsuccessful. Enactment will be unlikely without public support, yet little research is available to assess how to effectively make the case for such taxes.

PURPOSE

The objectives were to assess public opinion about arguments used commonly in tax debates regarding sugar-sweetened beverages and to assess differences in public opinion by respondents' political party affiliation.

METHODS

A public opinion survey was fielded in January-March 2011 using a probability-based sample of respondents from a large, nationally representative online panel to examine public attitudes about nine pro- and eight anti-tax arguments. These data were analyzed in August 2011.

RESULTS

Findings indicated greater public agreement with anti- than pro-tax arguments. The most popular anti-tax argument was that a tax on sugar-sweetened beverages is arbitrary because it does not affect consumption of other unhealthy foods (60%). A majority also agreed that such taxes were a quick way for politicians to fill budget holes (58%); an unacceptable intrusion of government into people's lives (53.8%); opposed by most Americans (53%); and harmful to the poor (51%). No pro-tax arguments were endorsed by a majority of the public. Respondents reported highest agreement with the argument that sugar-sweetened beverages were the single largest contributor to obesity (49%) and would raise revenue for obesity prevention (41%).

CONCLUSIONS

Without bolstering public support for existing pro-tax messages or developing alternative pro-tax messages, enacting such policies will be difficult. Message-framing studies could be useful in identifying promising strategies for persuading Americans that taxes on sugar-sweetened beverages are warranted.

Differences in perceptions and fast food eating behaviours between Indians living in high- and low-income neighbourhoods of Chandigarh, India

BACKGROUND

Increased density of fast food restaurants is associated with increased prevalence of obesity in developed countries. However, less is known about this relationship in developing countries undergoing rapid urbanization and how differences in neighbourhood income affect the patronage of fast food outlets. The purpose of the study is to explore the differences in fast food preferences, perceptions, and patronage between Indians living in high- and low-income neighbourhoods.

METHODS

This cross-sectional study recruited 204 men and women (35 to 65 years in age) from high- and low-income neighbourhoods who completed a questionnaire on fast food consumption. The questionnaire asked participants to define fast food and to provide reasons for and frequency of visits to fast food restaurants. The differences were analyzed using Chi square and t-tests for categorical and continuous variables, respectively.

RESULTS

Participants from a high-income neighbourhood were more likely to perceive Western -style fast food as fast food, while people from the low-income neighbourhood were more likely to identify food sold by street vendors as fast food (p <0.001). Furthermore, compared to participants from the high-income neighbourhood, people from the low-income neighbourhood were more likely to report buying food from street vendors while less likely to dine out at both fast food and non-fast food restaurants (p<0.001). Although the high-income neighbourhood group was more likely to report enjoying eating at fast food restaurants than their low-income neighbourhood counterparts, there were no significant differences in the reasons for visiting fast food restaurants (convenience, price, social enjoyment, and quality of meals) between the two groups. Both groups preferred home cooked over restaurant meals, and they recognized that home cooked food was healthier.

CONCLUSIONS

Overall, consumption of fast food was low. People from a high-income neighbourhood dined out more frequently and were more likely to perceive Western-style food as fast food compared to their counterparts from the low-income neighbourhood.

Food prices and blood cholesterol

Cardiovascular diseases (CVD) cost Americans billions of dollars per year. High cholesterol levels, which are closely related to dietary habits, are a major contributor to CVD. In this article, we study whether changes in food prices are related to cholesterol levels and whether taxes or subsidies on particular foods would be effective in lowering cholesterol levels and, consequently, CVD costs. We find that prices of vegetables, processed foods, whole milk and whole grains are significantly associated with blood cholesterol levels. Having analyzed the costs and benefits of government interventions, we find that a subsidy of vegetables and whole grains would be an efficient way to reduce CVD expenditures.

Fast-food and full-service restaurant consumption among children and adolescents: effect on energy, beverage, and nutrient intake

OBJECTIVE

To examine the effect of fast-food and full-service restaurant consumption on total energy intake, dietary indicators, and beverage consumption.

DESIGN

Individual-level fixed-effects estimation based on 2 nonconsecutive 24-hour dietary recalls.

SETTING

Nationally representative data from the 2003-2004, 2005-2006, and 2007-2008 National Health and Nutrition Examination Survey.

PARTICIPANTS

Children aged 2 to 11 years (n = 4717) and adolescents aged 12 to 19 years (n = 4699).

MAIN OUTCOME MEASURES

Daily total energy intake in kilocalories; intake of grams of sugar, total fat, saturated fat, and protein and milligrams of sodium; and total grams of sugar-sweetened beverages, regular soda, and milk consumed.

RESULTS

Fast-food and full-service restaurant consumption, respectively, was associated with a net increase in daily total energy intake of 126.29 kcal and 160.49 kcal for children and 309.53 kcal and 267.30 kcal for adolescents and with higher intake of regular soda (73.77 g and 88.28 g for children and 163.67 g and 107.25 g for adolescents) and sugar-sweetened beverages generally. Fast-food consumption increased intake of total fat (7.03-14.36 g), saturated fat (1.99-4.64 g), and sugar (5.71-16.24 g) for both age groups and sodium (396.28 mg) and protein (7.94 g) for adolescents. Full-service restaurant consumption was associated with increases in all nutrients examined. Additional key findings were (1) adverse effects on diet were larger for lower-income children and adolescents and (2) among adolescents, increased soda intake was twice as large when fast food was consumed away from home than at home.

CONCLUSION

Fast-food and full-service restaurant consumption is associated with higher net total energy intake and poorer diet quality.

Food pricing strategies, population diets, and non-communicable disease: a systematic review of simulation studies

BACKGROUND

Food pricing strategies have been proposed to encourage healthy eating habits, which may in turn help stem global increases in non-communicable diseases. This systematic review of simulation studies investigates the estimated association between food pricing strategies and changes in food purchases or intakes (consumption) (objective 1); Health and disease outcomes (objective 2), and whether there are any differences in these outcomes by socio-economic group (objective 3).

METHODS AND FINDINGS

Electronic databases, Internet search engines, and bibliographies of included studies were searched for articles published in English between 1 January 1990 and 24 October 2011 for countries in the Organisation for Economic Co-operation and Development. Where ≥ 3 studies examined the same pricing strategy and consumption (purchases or intake) or health outcome, results were pooled, and a mean own-price elasticity (own-PE) estimated (the own-PE represents the change in demand with a 1% change in price of that good). Objective 1: pooled estimates were possible for the following: (1) taxes on carbonated soft drinks: own-PE (n  =  4 studies), -0.93 (range, -0.06, -2.43), and a modelled -0.02% (-0.01%, -0.04%) reduction in energy (calorie) intake for each 1% price increase (n  =  3 studies); (2) taxes on saturated fat: -0.02% (-0.01%, -0.04%) reduction in energy intake from saturated fat per 1% price increase (n  =  5 studies); and (3) subsidies on fruits and vegetables: own-PE (n = 3 studies), -0.35 (-0.21, -0.77). Objectives 2 and 3: variability of food pricing strategies and outcomes prevented pooled analyses, although higher quality studies suggested unintended compensatory purchasing that could result in overall effects being counter to health. Eleven of 14 studies evaluating lower socio-economic groups estimated that food pricing strategies would be associated with pro-health outcomes. Food pricing strategies also have the potential to reduce disparities.

CONCLUSIONS

Based on modelling studies, taxes on carbonated drinks and saturated fat and subsidies on fruits and vegetables would be associated with beneficial dietary change, with the potential for improved health. Additional research into possible compensatory purchasing and population health outcomes is needed.

Planning and Development of the Better Bites Program

The Better Bites program, a hospital cafeteria nutrition intervention strategy, was developed by combining evidence-based practices with hospital-specific formative research, including key informant interviews, the Nutrition Environment Measures Study in Restaurants, hospital employee surveys, and nutrition services staff surveys. The primary program components are pricing manipulation and marketing to promote delicious, affordable, and healthy foods to hospital employees and other cafeteria patrons. The pricing manipulation component includes decreasing the price of the healthy items and increasing the price of the unhealthy items using a 35% price differential. Point-of-purchase marketing highlights taste, cost, and health benefits of the healthy items. The program aims to increase purchases of healthy foods and decrease purchases of unhealthy foods, while maintaining revenue neutrality. This article addresses the formative research, planning, and development that informed the Better Bites program.

Neighborhood disparities in access to healthy foods and their effects on environmental justice

Environmental justice is concerned with an equitable distribution of environmental burdens. These burdens comprise immediate health hazards as well as subtle inequities, such as limited access to healthy foods. We reviewed the literature on neighborhood disparities in access to fast-food outlets and convenience stores. Low-income neighborhoods offered greater access to food sources that promote unhealthy eating. The distribution of fast-food outlets and convenience stores differed by the racial/ethnic characteristics of the neighborhood. Further research is needed to address the limitations of current studies, identify effective policy actions to achieve environmental justice, and evaluate intervention strategies to promote lifelong healthy eating habits, optimum health, and vibrant communities.

Population approaches to improve diet, physical activity, and smoking habits: a scientific statement from the American Heart Association

BACKGROUND

Poor lifestyle behaviors, including suboptimal diet, physical inactivity, and tobacco use, are leading causes of preventable diseases globally. Although even modest population shifts in risk substantially alter health outcomes, the optimal population-level approaches to improve lifestyle are not well established.

METHODS AND RESULTS

For this American Heart Association scientific statement, the writing group systematically reviewed and graded the current scientific evidence for effective population approaches to improve dietary habits, increase physical activity, and reduce tobacco use. Strategies were considered in 6 broad domains: (1) Media and educational campaigns; (2) labeling and consumer information; (3) taxation, subsidies, and other economic incentives; (4) school and workplace approaches; (5) local environmental changes; and (6) direct restrictions and mandates. The writing group also reviewed the potential contributions of healthcare systems and surveillance systems to behavior change efforts. Several specific population interventions that achieved a Class I or IIa recommendation with grade A or B evidence were identified, providing a set of specific evidence-based strategies that deserve close attention and prioritization for wider implementation. Effective interventions included specific approaches in all 6 domains evaluated for improving diet, increasing activity, and reducing tobacco use. The writing group also identified several specific interventions in each of these domains for which current evidence was less robust, as well as other inconsistencies and evidence gaps, informing the need for further rigorous and interdisciplinary approaches to evaluate population programs and policies.

CONCLUSIONS

This systematic review identified and graded the evidence for a range of population-based strategies to promote lifestyle change. The findings provide a framework for policy makers, advocacy groups, researchers, clinicians, communities, and other stakeholders to understand and implement the most effective approaches. New strategic initiatives and partnerships are needed to translate this evidence into action.

Obesity prevention: the impact of local health departments

OBJECTIVE

To examine the association between bodyweight status and provision of population-based prevention services.

DATA SOURCES

The National Association of City and County Health Officials 2005 Profile survey data, linked with two cross-sections of the Behavioral Risk Factor Surveillance System (BRFSS) survey in 2004 and 2005.

STUDY DESIGN

Multilevel logistic regressions were used to examine the association between provision of obesity-prevention services and the change in risk of being obese or morbidly obese among BRFSS respondents. The estimation sample was stratified by sex. Low-income samples were also examined. Falsification tests were used to determine whether there is counterevidence.

PRINCIPAL FINDINGS

Provision of population-based obesity-prevention services within the jurisdiction of local health departments and specifically those provided by the local health departments are associated with reduced risks of obesity and morbid obesity from 2004 to 2005. The magnitude of the association appears to be stronger among low-income populations and among women. Results of the falsification tests provide additional support of the main findings.

CONCLUSIONS

Population-based obesity-prevention services may be useful in containing the obesity epidemic.

Weight misperceptions and racial and ethnic disparities in adolescent female body mass index

This paper investigated weight misperceptions as determinants of racial/ethnic disparities in body mass index (BMI) among adolescent females using data from the National Survey of Youth 1997. Compared to their white counterparts, higher proportions of black and Hispanic adolescent females underperceived their weight status; that is, they misperceived themselves to have lower weight status compared to their clinically defined weight status. Compared to their black counterparts, higher proportions of white and Hispanic adolescent females misperceived themselves to be heavier than their clinical weight status. Oaxaca-Blinder decomposition analysis showed that accounting for weight misperceptions, in addition to individual and contextual factors, increased the total explained portion of the black-white female BMI gap from 44.7% to 54.3% but only slightly increased the total explained portion of the Hispanic-white gap from 62.8% to 63.1%. Weight misperceptions explained 13.0% of the black-white female BMI gap and 3.3% of the Hispanic-white female BMI gap. The regression estimates showed that weight underperceptions were important determinants of adolescent female BMI, particularly among black and Hispanic adolescents. Education regarding identification and interpretation of weight status may play an important role to help reduce the incidence and racial disparity of female adolescent obesity.

A penny-per-ounce tax on sugar-sweetened beverages would cut health and cost burdens of diabetes

Sugar-sweetened beverages are a major contributor to the US obesity and diabetes epidemics. Using the Coronary Heart Disease Policy Model, we examined the potential impact on health and health spending of a nationwide penny-per-ounce excise tax on these beverages. We found that the tax would reduce consumption of these beverages by 15 percent among adults ages 25-64. Over the period 2010-20, the tax was estimated to prevent 2.4 million diabetes person-years, 95,000 coronary heart events, 8,000 strokes, and 26,000 premature deaths, while avoiding more than $17 billion in medical costs. In addition to generating approximately $13 billion in annual tax revenue, a modest tax on sugar-sweetened beverages could reduce the adverse health and cost burdens of obesity, diabetes, and cardiovascular diseases.

Introducing taxes, subsidies or both: the effects of various food pricing strategies in a web-based supermarket randomized trial

OBJECTIVE

Fiscal policies may form a solution in improving dietary intake. This study aimed to examine the effectiveness of varying taxing and subsiding schemes to stimulate healthier food purchases.

METHODS

A randomized controlled trial with three levels of price reduction on healthy foods (no; 25%; 50%)×three levels of price increase on unhealthy foods (5%; 10%; 25%) factorial design was used. 150 participants were randomized into one of nine conditions and were asked to purchase groceries at a web-based supermarket. Data were collected in the Netherlands in January-February 2010 and analyzed using analysis of covariance.

RESULTS

Subjects receiving 50% discount purchased significantly more healthy foods than subjects receiving no (mean difference=6.62 items, p<0.01) or 25% discount (mean difference=4.87 items, p<0.05). Moreover, these subjects purchased more vegetables (mean difference=821 g;p<0.05 compared to no discount). However, participants with the highest discount also purchased significantly more calories. No significant effects of the price increases on unhealthy foods were found.

CONCLUSION

Price decreases are effective in stimulating healthy food purchases, but the proportion of healthy foods remains unaffected. Price increases up to 25% on unhealthier products do not significantly affect food purchases. Future studies are important to validate these results in real supermarkets and across different countries.

Retail grocery store marketing strategies and obesity: an integrative review

CONTEXT

In-store food marketing can influence food-purchasing behaviors and warrants increased attention given the dramatic rise in obesity. Descriptive and experimental studies of key marketing components have been conducted by consumer scientists, marketing researchers, and public health experts. This review synthesizes research and publications from industry and academic sources and provides direction for developing and evaluating promising interventions.

EVIDENCE ACQUISITION

Literature sources for the review were English-language articles published from 1995 to 2010, identified from multidisciplinary search indexes, backward searches of cited articles, review articles, industry reports, and online sources. Only articles that focused on physical grocery stores and food products were included. Data collection occurred in 2010 and 2011.

EVIDENCE SYNTHESIS

Articles were classified in the categories of product, price, placement, and promotion and divided into controlled laboratory experiments, observation, and field experiments; 125 primary peer-reviewed articles met the inclusion criteria. Narrative synthesis methods were used. Key findings were synthesized by category of focus and study design. Evidence synthesis was completed in 2011.

CONCLUSIONS

Findings suggest several strategies for in-store marketing to promote healthful eating by increasing availability, affordability, prominence, and promotion of healthful foods and/or restricting or de-marketing unhealthy foods. Key results of research in controlled laboratory studies should be adapted and tested in real-world in-store settings. Industry methods for assessing consumer behavior, such as electronic sales data and individually linked sales information from loyalty card holders, can help public health researchers increase the scientific rigor of field studies.

A consideration of user financial incentives to address health inequalities

Health inequalities and user financial incentives to encourage health-related behavior change are two topical issues in the health policy discourse, and this article attempts to combine the two; namely, we try to address whether the latter can be used to reduce the former in the contexts of the United Kingdom and the United States. Payments for some aspects of medical adherence may offer a promising way to address, to some extent, inequalities in health and health care in both countries. However, payments for more sustained behavior change, such as that associated with smoking cessation and weight loss, have thus far shown little long-term effect, although more research that tests the effectiveness of different incentive mechanism designs, informed by the findings of behavioral economics, ought to be undertaken. Many practical, political, ethical, and ideological objections can be waged against user financial incentives in health, and this article reviews a number of them, but the justifiability of and limits to these incentives require more academic and public discourse so as to gain a better understanding of the circumstances in which they can legitimately be used.

Experimental research on the relation between food price changes and food-purchasing patterns: a targeted review

One way in which to modify food purchases is to change prices through tax policy, subsidy policy, or both. We reviewed the growing body of experimental research conducted in the laboratory and in the field that investigates the following: the extent to which price changes influence purchases of targeted and nontargeted foods, total energy, or macronutrients purchased; the interaction of price changes with adjunctive interventions; and moderators of sensitivity to price changes. After a brief overview of economic principles and observational research that addresses these issues, we present a targeted review of experimental research. Experimental research suggests that price changes modify purchases of targeted foods, but research on the overall nutritional quality of purchases is mixed because of substitution effects. There is mixed support for combining price changes with adjunctive interventions, and there are no replicated findings on moderators to price sensitivity in experiments. Additional focused research is needed to better inform food policy development with the aim of improving eating behavior and preventing obesity.

Supplemental nutrition assistance program and body weight outcomes: the role of economic contextual factors

We explored the extent to which economic contextual factors moderated the association of Supplemental Nutrition Assistance Program (SNAP) participation with body mass index (BMI) among low-income adults whose family income (adjusted for family size) is less than 130% of the federal poverty guideline. We drew on individual-level data from the Panel Study of Income Dynamics in the United States, including three waves of data in 1999, 2001, and 2003. Economic contextual data were drawn from the American Chamber of Commerce Researchers Association for food prices and Dun & Bradstreet for food outlet measures. In addition to cross-sectional estimation, a longitudinal individual fixed effects model was used to control for permanent unobserved individual heterogeneity. Our study found a statistically significant joint moderating effect of the economic contextual factors in longitudinal individual fixed effects model for both women (BMI only) and men (both BMI and obesity). For both women and men, SNAP participants' BMI was statistically significantly lower if they faced increased numbers of available supermarkets/grocery stores in the longitudinal model. A simulated 20% reduction in the price of fruits and vegetables resulted in a larger decrease in BMI among SNAP participants than non-participants for women and men, whereas a simulated 20% increase in the availability of supermarkets and grocery stores resulted in a statistically significant difference in the change in BMI by SNAP participation for women but not for men. Policies related to economic contextual factors, such as subsidies for fruits and vegetables or those that would improve access to supermarkets and grocery stores may enhance the relationship between SNAP participation and body mass outcomes among food assistance program participants.

Do economic constraints on food choice make people fat? A critical review of two hypotheses for the poverty-obesity paradox

In low income countries worldwide, rising standards of living have spurred an unprecedented rise in obesity. However, in numerous wealthy countries the trend frequently reverses with poorer and less educated women more likely to be overweight than their wealthier compatriots. One prominent explanation for this reverse gradient is that economic deprivation leads to food choices which paradoxically increase energy intake. If true, this would challenge current evolutionary accounts for the modern obesity epidemic and have serious implications for how policy makers tackle increasing obesity in the US and worldwide. In this article, we critically review the hypothesis that deprivation leads people to choose cheaper foods which in turn foster overconsumption of energy. Though the hypothesis is consistent with numerous cross-sectional studies, available longitudinal studies from high-, middle-, and low-income countries show the reverse-that when populations experience resource declines, they experience either declines in BMI or decelerations in BMI growth. Most notably, the recent recession in the US coincides with a clear deceleration in women's obesity across income groups. We conclude by briefly reviewing other plausible explanations for the reverse gradient among women in developing countries. Finally, we discuss how theoretical perspectives and comparative, historical approaches from human biology are useful tools for examining the current wealth of hypotheses about obesity in population health.