Although healthy foods can be affordable, if less healthy foods are cheaper, individuals may have an economic incentive to consume a less healthful diet. Using the Quarterly Food-at-Home Price Database, the authors explore whether a select set of healthy foods (whole grains, dark green vegetables, orange vegetables, whole fruit, skim and 1% milk, fruit juice, and bottled water) are more expensive than less healthy alternatives. They find that not all healthy foods are more expensive than less healthy alternatives. They also find considerable geographic variation in the relative price of healthy foods. This price variation may contribute to geographic variation in diet and health outcomes. Charts and tables. This is a print on demand report.

Although healthy foods can be affordable, if less healthy foods are cheaper, individuals may have an economic incentive to consume a less healthful diet. Using the Quarterly Food-at-Home Price Database, we explore whether a select set of healthy foods (whole grains, dark green vegetables, orange vegetables, whole fruit, skim and 1% milk, fruit juice, and bottled water) are more expensive than less healthy alternatives. We find that not all healthy foods are more expensive than less healthy alternatives; skim and 1% milk are less expensive than whole and 2% milk and bottled water is generally less expensive than carbonated nonalcoholic drinks. We also find considerable geographic variation in the relative price of healthy foods. This price variation may contribute to geographic variation in diet and health outcomes.

Considering the detrimental environmental impact of current food systems, and the concerns raised about their sustainability, there is an urgent need to promote diets that are healthy and have low environmental impacts. These diets also need to be socio-culturally acceptable and economically accessible for all. Acknowledging the existence of diverging views on the concepts of sustainable diets and healthy diets, countries have requested guidance from the Food and Agriculture Organization of the United Nations (FAO) and the World Health Organization (WHO) on what constitutes sustainable healthy diets. These guiding principles take a holistic approach to diets; they consider international nutrition recommendations; the environmental cost of food production and consumption; and the adaptability to local social, cultural and economic contexts. This publication aims to support the efforts of countries as they work to transform food systems to deliver on sustainable healthy diets, contributing to the achievement of the SDGs at country level, especially Goals 1 (No Poverty), 2 (Zero Hunger), 3 (Good Health and Well-Being), 4 (Quality Education), 5 (Gender Equality) and 12 (Responsible Consumption and Production) and 13 (Climate Action).

In the United States, people living in low-income neighborhoods frequently do not have access to affordable healthy food venues, such as supermarkets. Instead, those living in "food deserts" must rely on convenience stores and small neighborhood stores that offer few, if any, healthy food choices, such as fruits and vegetables. The Institute of Medicine (IOM) and National Research Council (NRC) convened a two-day workshop on January 26-27, 2009, to provide input into a Congressionally-mandated food deserts study by the U.S. Department of Agriculture's Economic Research Service. The workshop, summarized in this volume, provided a forum in which to discuss the public health effects of food deserts.

OBJECTIVE: This dissertation first evaluates food price variation within and between neighborhoods in order to improve our understanding of access to healthy foods and potential economic incentives and barriers to consuming a higher quality diet. The study then spatially links individuals to their nearby supermarkets to study the association between food price and dietary quality, insulin resistance (IR), and diabetes. METHODS: Prices of healthy foods (dairy, fruits, and vegetables) and unhealthy foods (soda, sweets, and salty snacks) were obtained from 1953 supermarkets across the US during 2009-2012 from the Information Resources Inc. (IRI) database. In Aim 1, prices of healthy and unhealthy foods, and the relative price of healthy foods compared with unhealthy foods (healthy-to-unhealthy price ratio) were linked to census block group socio-demographics in order to analyze associations between food prices with neighborhood SES and proportion Black/Hispanic. Linear hierarchical regression models were used to explore geospatial variation and adjust for confounders. The second and third aims of this study linked average price of healthy foods, unhealthy foods and their ratio to participants in The Multi-Ethnic Study of Atherosclerosis (MESA). For Aim 2, individuals who completed MESA exam 5 (2010-2012) and the food frequency questionnaire were included (N=2765). A Healthy Eating Index (HEI-2010) was calculated for each individual according to their FFQ. Logistic regression estimated adjusted odds ratios of a high quality diet (top quantile of HEI-2010) associated with each price exposure. Sensitivity analyses used an instrumental variable approach in which the price of brand name toilet paper served as an instrument for food prices. For Aim 3, individuals from MESA who completed exam 5 and exam 4 (administered five years prior, diabetes incidence analysis only) were included. Type 2 diabetes status was confirmed at each exam and IR was measured according to the homeostasis model assessment index of IR. Adjusted logistic, modified Poisson and linear regression models were used to model diabetes prevalence, incidence and IR, respectively. RESULTS: Overall, the price of healthy foods was nearly twice as high as the price of unhealthy foods ($0.590 vs. $0.298 per serving; healthy-to-unhealthy price ratio of 1.99). This trend was consistent across all neighborhood characteristics. After adjusting for covariates, no association was found between food prices (healthy, unhealthy, or the healthy-to-unhealthy ratio) and neighborhood SES, while small positive and negative associations were detected with the proportion Black/Hispanic, respectively. A larger healthy-to-unhealthy price ratio was associated with lower odds of having a high quality diet (Odds Ratio [OR]=0.76 per SD increase in the ratio, 95% CI=[0.64 to 0.91]). Instrumental variable analyses largely confirmed these findings although confidence intervals were wider and the result was no longer statistically significant (OR=0.82 [0.57 to 1.19]). A higher ratio of healthy-to-unhealthy food had a positive association with IR (4.8% increase in IR for each standard deviation increase in price ratio (estimate=0.048, 95% CI=[0.00 to 0.10]) after adjusting for confounders. No association with diabetes incidence (relative risk=1.11, 95% CI=[0.85 to 1.44]) or prevalence (OR=0.95, 95% CI=[0.81 to 1.11]) was observed. CONCLUSIONS: The price of healthy food was twice as expensive as unhealthy food per serving on average. A higher price of healthy food relative to unhealthy foods appears to be negatively associated with a high quality diet and with insulin resistance. There did not appear to be an association with diabetes prevalence or 5-year incidence. This study provides new insight into the relationship between food prices with diet quality, IR and diabetes. Policies to address the large price differences between healthy and unhealthy foods may help improve diet quality and downstream health effects in the U.S.

The U.S. food system provides many benefits, not the least of which is a safe, nutritious and consistent food supply. However, the same system also creates significant environmental, public health, and other costs that generally are not recognized and not accounted for in the retail price of food. These include greenhouse gas (GHG) emissions, soil erosion, air pollution, and their environmental consequences, the transfer of antibiotic resistance from food animals to human, and other human health outcomes, including foodborne illnesses and chronic disease. Some external costs which are also known as externalities are accounted for in ways that do not involve increasing the price of food. But many are not. They are borne involuntarily by society at large. A better understanding of external costs would help decision makers at all stages of the life cycle to expand the benefits of the U.S. food system even further. The Institute of Medicine (IOM) and the National Research Council (NRC) with support from the U.S. Centers for Disease Control and Prevention (CDC) convened a public workshop on April 23-23, 2012, to explore the external costs of food, methodologies for quantifying those costs, and the limitations of the methodologies. The workshop was intended to be an information-gathering activity only. Given the complexity of the issues and the broad areas of expertise involved, workshop presentations and discussions represent only a small portion of the current knowledge and are by no means comprehensive. The focus was on the environmental and health impacts of food, using externalities as a basis for discussion and animal products as a case study. The intention was not to quantify costs or benefits, but rather to lay the groundwork for doing so. A major goal of the workshop was to identify information sources and methodologies required to recognize and estimate the costs and benefits of environmental and public health consequences associated with the U.S. food system. It was anticipated that the workshop would provide the basis for a follow-up consensus study of the subject and that a central task of the consensus study will be to develop a framework for a full-scale accounting of the environmental and public health effects for all food products of the U.S. food system. Exploring Health and Environmental Costs of Food: Workshop Summary provides the basis for a follow-up planning discussion involving members of the IOM Food and Nutrition Board and the NRC Board on Agriculture and Natural Resources and others to develop the scope and areas of expertise needed for a larger-scale, consensus study of the subject.