the three studies that also examined dietary data, one showed increased consumption of healthier foods and two did not register impacts. Based on this review, Gittelsohn concluded that informational shelf labeling seems to work, while incentives, in the form of coupons, had little impact. However, a longer duration of up to two years may be needed to show any significant change.
Since 2004-2005, researchers have conducted a number of intervention trials in small stores, which are often the main source of retail food purchases among low-income, ethnic, minority populations. Gittelsohn and a colleague are now in the process of reviewing 14 such studies: 5 studies confined to the stores and 9 that combined in-store interventions with community social marketing. These studies indicate a potential for success, as measured by reported improvements in fruit and vegetable sales, consumer psychosocial behaviors, healthy food purchasing patterns, and consumer diet. Challenges to increasing fruit and vegetable availability in small stores include convincing store owners to stock healthier foods, especially fresh fruits and vegetables that are perishable and require special handling. He suggested first trying to convince small store owners to stock less risky (e.g., nonperishable) healthy foods, such as low-sugar or high-fiber cereals. In many cases, store layouts pose a barrier; some are so enclosed that customers cannot touch a food item until they purchase it. These closed settings also severely limit social engagement between the customer and the clerk and therefore create barriers for nutrition education opportunities.
Types of price manipulation include lowering prices of healthy foods, offering coupons and other incentives, and increasing prices of unhealthy foods to subsidize lowering the costs of healthy foods. The CHIPS (Changing Individuals’ Purchase of Snacks) study (French et al., 2001) showed that modifying the prices of low-fat snacks in vending machines increased sales and did not decrease profits. Other studies have looked at price subsidies in school cafeterias and showed that healthier food intake continued even when the subsidies stopped. Gittelsohn stated that research on price manipulation in stores as a public health intervention is needed, but one difficulty in setting up a price trial in a food store is that retailers are reluctant to share their pricing strategies or to give up control over this key aspect of their business.
Other questions to resolve in changing the food environment include how to build and sustain community support, the role of locally produced foods, and the optimal combination of institutions to involve. Certain aspects of the food environment have been commonly measured, while