The study, published in the journal Frontiers in Sustainability, was led by scientists at the Research Institute of Organic Agriculture (FiBL) in Switzerland together with partners at Justus Liebig University Giessen and the German Federal Environment Agency (UBA). The team developed a generic framework for comparing the sustainability performance of large food retailers and then applied it in a pilot assessment of the environmental dimension in Germany, using 2020 as the reference year. The results paint a picture of an industry that has embraced the language of sustainability while leaving much of its transformative potential untapped.

The scale of the retail sector’s influence explains why the researchers focused on supermarkets rather than farms or factories. According to a sector inquiry by the German Federal Cartel Office, food retailers account for between 65 and 90 percent of manufacturers’ total sales, depending on the procurement market, and roughly three-quarters of consumers’ monthly household food spending flows through retail outlets. In Germany, the eight food retailers with the highest revenues—belonging to just four corporations—generated more than 75 percent of total food retail revenues in 2022. Vertical integration and the expansion of private-label brands give these companies direct leverage over product specifications and supply chains that few other actors in the food system can match.

To capture this leverage systematically, the researchers structured their framework around four spheres of influence that any large retailer can exercise regardless of the sustainability issue at stake. First, companies can reduce impacts within their own organizations through building insulation, refrigeration technology, logistics, waste management, and staff training. Second, they can shape upstream supply chains through procurement requirements, product specifications, and third-party certification standards. Third, they can influence consumer choices through assortment, store and shelf design, advertising, and pricing. Fourth, as major economic actors, they can engage with the policy framework within which the entire sector operates.

The methodological architecture of the assessment is what distinguishes it from previous benchmarking exercises. Existing approaches—life-cycle assessment, the FAO’s SAFA Guidelines, the World Benchmarking Alliance rankings, WWF rating schemes, and ESG reporting frameworks—each capture parts of the picture but differ markedly in scope, data sources, and how they treat retailers’ influence over suppliers, consumers, and policy. The new framework instead adopts an action-oriented structure: rather than trying to measure environmental outcomes directly, which is complicated by data gaps and the notorious difficulty of allocating impacts across co-products in agriculture, it evaluates how thoroughly companies use the levers actually available to them. Each field of action is assessed through indicators scored on a scale from 1, meaning no practice, to 5, meaning best practice.

In the German pilot, the team operationalised 22 fields of action, 43 indicators, and 112 sub-indicators across the supply chain, own sites, and consumption spheres, covering four environmental categories: climate, soil, biodiversity including deforestation, and oceans. Data collection proceeded in two stages. Questionnaires were first pre-filled with publicly available information from sustainability reports and press releases, then sent to the companies for correction and supplementation. Indicator weights were derived from nine independent expert judgements using the Best-Worst Method, a technique chosen because it requires fewer pairwise comparisons than the widely used Analytical Hierarchy Process while providing a built-in consistency check. Sensitivity analyses tested whether the company rankings would hold under alternative weighting schemes—and they largely did.

The findings reveal a consistent pattern across all three spheres of influence. In the supply chain, companies scored on average between no practice and average practice, with communication-related performance stronger than strategy, which in turn outpaced implementation. The lowest scores appeared precisely where substantive change happens: in measures for sustainable product-range design, such as traceability systems, increasing the share of certified products, and strengthening procurement guidelines, which were on average only partially implemented. Several corporate targets failed to meet the SMART criteria—specific, measurable, ambitious, realistic, and time-bound—undermining their usefulness as management tools.

At companies’ own sites, the same hierarchy repeated itself, and some gaps were particularly stark. None of the eight retailers could provide quantitative information on reductions in food waste at its own locations. Issues such as sustainable investment criteria for occupational pension schemes had not yet been integrated into corporate strategies. The researchers noted that external regulatory and economic pressures, including refrigeration requirements and energy-efficiency rules, created clear incentives for change, whereas the scope for differentiation through purely voluntary measures appeared comparatively limited. In the consumption sphere, all companies ran environmental or awareness campaigns, but information on investment levels, duration, and reach was too incomplete for systematic comparison, and certified or plant-based products remained a small share of most relevant assortments.

Across environmental categories, climate dominated corporate attention, with most companies seeking to derive targets from scientific evidence through initiatives such as the Science Based Targets initiative. Deforestation was addressed by all companies, while biodiversity featured in the strategies of only a subset, and soil received comparatively little attention at either the strategic or implementation level. Interestingly, discounters such as ALDI SÜD, ALDI Nord, and Lidl performed better in the supply-chain sphere, plausibly because their higher private-label shares give them more direct control over raw-material procurement, while full-range retailers matched or exceeded them in consumer-facing activities. No company demonstrated consistently leading performance across all fields.

Perhaps the most consequential finding concerns the economics of sustainability. Many of the measures retailers had implemented aligned with direct business benefits—energy savings, premium product revenues, reputational gains—while measures that could conflict with short-term commercial interests were rare, even where they could contribute substantially to environmental objectives. Limiting advertising for animal products or off-season goods, for example, was largely absent. The authors argue that fields where all companies perform poorly may reflect structural constraints that individual firms cannot resolve alone, pointing toward a role for policy: internalizing external costs, setting minimum supply-chain standards, and eliminating particularly harmful practices such as air-freighted food. The framework itself, the researchers emphasize, is transferable in structure even though the German scores are not, and a follow-up assessment using 2023 data has already extended the approach to social responsibility and animal welfare—evidence that transparent, repeatable benchmarking can become a standing instrument for holding the food system’s most powerful gatekeepers to account.

Subject of Research: A generic framework for comparative sustainability assessment of large food retailers, piloted on the environmental performance of Germany's eight biggest grocery companies

Article Title: Assessing the sustainability performance of large food retail companies: a generic framework and pilot application to the environmental dimension in Germany

Article References: Schader, C., Keller, O., Teriete, M., Sander, M., Schafhausen, C., Herzig, C., & Seo, H. (2026). Assessing the sustainability performance of large food retail companies: a generic framework and pilot application to the environmental dimension in Germany. Frontiers in Sustainability, 7, Article 1720594. https://doi.org/10.3389/frsus.2026.1720594

Image Credits: AI Generated

DOI: 10.3389/frsus.2026.1720594

Keywords: food retail, sustainability assessment, environmental performance, Germany, supermarkets, supply chain, benchmarking, indicators, food systems, corporate sustainability, planetary boundaries, sustainable consumption

The study is funded by a $1 million grant from the U.S. Department of Agriculture’s National Institute of Food and Agriculture, and it brings together collaborators with expertise spanning nutrition, agricultural economics, and community health. Feng’s team includes Sean Cash, an associate professor at Tufts University; Abby Gold, a health and nutrition specialist at the University of Minnesota; Denise Holston, an associate professor and nutrition specialist at Louisiana State University; and Qingxiao Li, an assistant professor of agricultural economics and agribusiness at LSU. The geographic focus on Minnesota and Louisiana is deliberate, pairing a largely rural Upper Midwest context with a Southern state where food access challenges and diet-related disease burdens are well documented.

The scale of dollar store expansion is striking. According to the data service company Statista, there were more than 39,000 dollar stores in the United States in 2025, an increase of 4,700 stores since 2021. Dollar General alone accounted for the highest number of locations in 2025, with 20,959 stores, more than Dollar Tree and Family Dollar combined. Perhaps most telling for food researchers: groceries made up more than 80 percent of Dollar General’s sales in 2025. While many retail sectors contracted or stagnated during the economic disruptions of 2020 and 2021, dollar stores grew aggressively, often opening in communities that larger grocery chains had abandoned.

That growth has made dollar stores the fastest-growing food-retail channel in rural America. A 2023 study led by Feng and published in the American Journal of Public Health examined dollar stores and food access for rural households across the United States. It found that from 2008 to 2020, dollar stores increased their share of rural household food purchases by 102.9 percent. In communities where the nearest supermarket may be a long drive away, the local dollar store can function as a de facto grocery store, and in some places it may be the only storefront selling food at all. That dual identity, as both a lifeline and a potential nutritional liability, sits at the center of the new research.

The public health concern is straightforward. Dollar stores tend to stock shelf-stable, heavily processed items: sugar-sweetened beverages, salty snacks, canned goods, and breakfast cereals, alongside limited protein options and little or no fresh produce. When such stores become a household’s primary food source, the resulting diet can skew toward calories dense in added sugars and sodium but low in nutrients. Feng’s earlier work, published this past fall in the Journal of the Academy of Nutrition and Dietetics, analyzed the healthfulness of foods purchased at dollar stores and documented these patterns in detail. The new study builds on that foundation by shifting from description to intervention, exploring concrete opportunities for nutritional improvement.

Feng frames the issue with nuance rather than alarm. Some shoppers, she notes, find dollar stores a convenient and affordable place to get food, especially those living far from traditional grocery stores. Others worry the stores may cause harm because they do not offer the healthiest options. The research team wants to understand how consumers actually incorporate this emerging retail format into their household food purchasing strategies, rather than assuming a single story of either benefit or harm. That consumer-centered perspective shapes the study’s methodology, which combines qualitative and computational approaches.

Technically, the project proceeds in three integrated phases. First, researchers will conduct interviews and focus groups with dollar store shoppers and community stakeholders in Minnesota and Louisiana, probing their perceptions and motivations as they work to fulfill their households’ dietary requirements. Second, the team will apply machine learning cluster analysis to food purchase data, a technique that groups households with statistically similar buying patterns and allows researchers to characterize distinct types of food purchase behavior. Each cluster can then be evaluated for healthfulness, and the strategies that consumers within healthier clusters use to maintain a nutritious diet with dollar store food can be identified and studied. Third, the team will translate those findings into educational resources designed to help low-income Americans achieve food and nutrition security and sustain better health over time.

The intervention phase will put those tools to the test. The researchers plan a pilot initiative using the educational resource toolkit with shoppers and other stakeholders in two communities in Minnesota and two in Louisiana. The toolkit is intended to improve understanding of nutrition, food affordability, and healthy shopping strategies, and the pilot may include workshops, community outreach programs, and cooking demonstrations, all carried out in collaboration with local organizations. This community-driven design reflects a deliberate choice: rather than prescribing solutions from outside, the team aims to build approaches that fit the real constraints and habits of dollar store shoppers, including tight budgets, limited transportation, and the practical realities of what is on the shelves.

The communities most affected by dollar store proliferation are also those with the least food retail choice. Feng notes that dollar store shopper demographics skew toward rural households, People of Color, and lower-income households, and that the data collected should help provide a well-rounded understanding of the dollar store phenomenon. Dollar stores have added a new dimension to food systems in all communities, but rural areas and lower-income communities with racial and ethnic minority households are especially impacted, both as customers and as sites of rapid store expansion. Understanding how these households navigate the trade-off between convenience, cost, and nutritional quality is essential for any policy or program that hopes to reduce diet-related health disparities.

The stakes extend beyond individual shopping carts. If dollar stores are now a structural pillar of food access for vulnerable populations, then improving what those stores sell, and how shoppers use them, could move the needle on nutrition insecurity at population scale. Feng’s goal, as she describes it, is to create a holistic and community-driven approach that helps dollar store shoppers fulfill their households’ need for healthy foods, make healthier choices, and ultimately contribute to reducing or eliminating nutrition insecurity. With insights gained through data collection and direct conversations with consumers, the team will develop tools to help shoppers stretch their food budget while using dollar stores as food retailers. If there is knowledge to be gained that promotes healthy eating with limited resources, Feng says, the team wants to share it. The three-year study promises to turn one of American retail’s most rapid expansions into one of its most closely examined public health experiments.

Subject of Research: The impact of dollar store food retail on household food purchases and nutrition security in rural and low-income American communities

Article Title: Assessing the fastest-growing food retailers—dollar stores

Article References: Assessing the fastest-growing food retailers—dollar stores. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: dollar stores, food retail, nutrition security, food access, rural communities, public health, USDA, Dollar General, diet quality, low-income households, machine learning, grocery shopping