The disproportionate burden of chronic disease among resource-limited populations with barriers to healthy food access is a major public health concern⁽ Reference Larson, Story and Nelson ^{1 )}. Food access, income and education have been shown to be interrelated factors in obesity risk⁽ Reference Dubowitz, Zenk and Ghosh-Dastidar ^{2 ,} Reference Ollberding, Nigg and Geller ^{3 )}. However, current food desert research suggests that simply increasing supermarket locations is insufficient to alter dietary behaviour⁽ Reference Dubowitz, Zenk and Ghosh-Dastidar ^{2 ,} Reference Burgoine, Mackenbach and Lakerveld ^{4 )}. The overall food environment in the neighbourhood may affect consumption more than supermarket distance⁽ Reference Fan, Hanson and Zick ^{5 )}. Social norms, cultural preferences, time constraints, transportation access and competition from less-healthy food sources may also shape residents’ perceptions of their available food choices⁽ Reference Pitt, Gallegos and Comans ^{6 –} Reference Caspi, Kawachi and Subramanian ^{9 )}. Thus, food access may be viewed as a multidimensional construct, encompassing availability, accessibility, affordability, accommodation and acceptability⁽ Reference Caspi, Kawachi and Subramanian ^{9 )}. Barriers related to any of these factors contribute to access disparities.

Interest in farmers’ market interventions to improve neighbourhood food access has grown rapidly in the past decade⁽ Reference Young, Karpyn and Uy ^{10 ,} Reference Cole, McNees and Kinney ^{11 )} Farmers’ markets may combine geographic flexibility, price sensitivity, cultural and community linkages in ways that address multiple dimensions of access⁽ Reference Sadler ^{12 –} Reference Evans, Jennings and Smiley ^{14 )}.

Tailoring farmers’ markets to address the access needs of low-income and ethnic minority communities, however, can be challenging⁽ Reference Inda, Washburn and Beckham ^{15 )}. Market managers need to understand neighbourhood demographics and engage community members, to ensure the market addresses their needs and preferences⁽ Reference Colasanti, Conner and Smalley ^{16 )}. Although most consumers view farmers’ markets positively as healthy food sources, price sensitivity for market produce varies strongly by income⁽ Reference Freedman, Vaudrin and Schneider ^{17 )}. For resource-constrained consumers, the ability to use federal food benefits at the market, and interventions that incentivize fruit/vegetable purchasing, can substantially impact accessibility⁽ Reference Jones and Bhatia ^{13 ,} Reference Bertmann, Ohri-Vachaspati and Buman ^{18 ,} Reference Freedman, Flocke and Shon ^{19 )}.

Farmers’ markets, however, are small businesses, not designed primarily as public health interventions⁽ Reference Hodgins and Fraser ^{20 )}. The infrastructure required to use federal food benefits at the market may be challenging for market owners to support⁽ Reference Buttenheim, Havassy and Fang ^{21 )}. While owners and managers value providing affordable healthy foods to all community members, market business plans may emphasize messaging and products that attract more affluent consumers⁽ Reference Guthman, Morris and Allen ^{22 )}. Racial, cultural and economic differences between rural farmers and low-income urban consumers can contribute to a perception that these markets are affluent or ‘white’ social spaces, reducing their accessibility to low-income and ethnic minority residents⁽ Reference Larimore ^{23 )}.

Working with farmers’ market programmes to build market access across these critical dimensions can be resource-intensive. Given limited resources, farmers’ market intervention efforts need to be strategic.

Results

The first analysis examined existing access of low-income individuals (below 200 % of the FPL) within the county of Honolulu to farmers’ markets (Fig. 1). In the county as a whole, three-quarters (74 %) of low-income individuals (below 200 % of the FPL) live within a reasonable distance (0·8 km (0·5mile) for urban areas; 8·0 km (5 miles) for rural areas) of a farmers’ market.

Fig. 1 Location and access boundaries of farmers’ markets and number of low-income individuals in census block groups, Honolulu County, Hawaii, USA, May 2017 (EBT, electronic benefit transfer; 1mile=1·6 km)

The second analysis examined existing access of SNAP participant households within Honolulu County to farmers’ markets that have EBT terminals where they can use their SNAP benefits to purchase food (Fig. 2). Less than half (44 %) of SNAP-participating households have access to farmers’ market with an EBT terminal.

Fig. 2 Location and access boundaries of farmers’ markets with EBT and number of SNAP participants in census block groups, Honolulu County, Hawaii, USA, May 2017 (EBT, electronic benefit transfer; SNAP, Supplemental Nutrition Assistance Program; 1 mile=1·6 km)

The third analysis looked at the impact of targeting market promotion at areas where low-income individuals are most concentrated. Two of the ten block groups have no farmers’ market within reasonable reach. Placing a farmers’ market accessible to these two block groups increases the percentage of low-income residents with access by only 4 %. (No figure provided for this analysis, since it made no substantive difference in access.)

Finally, the ten block groups with the most SNAP-participating households were identified and analysed (Fig. 3). Six have no farmers’ market that accepts EBT within reasonable reach. If one market accessible to each of these six block groups were to start accepting EBT, the access to farmers’ markets with EBT for the county’s SNAP participants would increase by 23 % (going from 44 % to 67 %).

Fig. 3 Location of farmers’ markets with EBT and access boundaries of the ten census block groups with the most SNAP participants, Honolulu County, Hawaii, USA, May 2017 (EBT, electronic benefit transfer; SNAP, Supplemental Nutrition Assistance Program; 1mile=1·6 km)