标题：Effect of a Targeted Subsidy on Intake of Fruits and Vegetables Among Low-Income Women in the Special Supplemental Nutrition Program for Women, Infants, and Children
摘要：Objectives. Intake of fruits and vegetables protects against several common chronic diseases, and low income is associated with lower intake. We tested the effectiveness of a subsidy for fruits and vegetables to the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC). Methods. Women who enrolled for postpartum services (n=602) at 3 WIC sites in Los Angeles were assigned to an intervention (farmers’ market or supermarket, both with redeemable food vouchers) or control condition (a minimal nonfood incentive). Interventions were carried out for 6 months, and participants’ diets were followed for an additional 6 months. Results. Intervention participants increased their consumption of fruits and vegetables and sustained the increase 6 months after the intervention was terminated (model adjusted R 2=.13, P <.001). Farmers’ market participants showed an increase of 1.4 servings per 4186 kJ (1000 kcal) of consumed food ( P <.001) from baseline to the end of intervention compared with controls, and supermarket participants showed an increase of 0.8 servings per 4186 kJ ( P =.02). Conclusions. Participants valued fresh fruits and vegetables, and adding them to the WIC food packages will result in increased fruit and vegetable consumption. Fruit and vegetable intake protects against various common chronic diseases. 1 – 4 Low income is a risk factor for poor dietary quality and for low consumption of fruits and vegetables. 1 – 5 Interventions using nutrition education to increase consumption of fruits and vegetables have reported some successes, although the magnitude of the behavior change has been modest. 6 Recent analyses have drawn attention to the potential for more “upstream” strategies, including policy, pricing, and environmental change to affect food access and availability as well as consumer information and motivation. 7 Strategies to promote the choice of targeted foods by lowering their cost relative to those of alternative foods have been little tested, probably because of the cost of implementing such strategies, but the available evidence suggests that they are highly effective. Reducing the prices of lower-fat vending-machine snacks, fresh fruits, and baby carrots in work sites and secondary schools has resulted in substantially increased sales of these items. 8 – 10 Two published reports on the provision of coupons for the purchase of fruits and vegetables at farmers’ markets, one with low-income older adults over a 5-year period 11 and the other for participants in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) in Connecticut, 10 showed high levels of coupon use. The WIC program provides an ideal context for investigating means to improve the consumption of fruits and vegetables. It is targeted to a low-income population and is designed to improve dietary quality both through subsidizing nutrient-dense foods and through nutrition education. The program currently reaches about half of all infants born in the United States, along with their mothers, and about 25% of preschool children. 12 The WIC program was developed prior to appreciation of the relationship of intake of fruits and vegetables to chronic disease risk, and the supplemental foods were selected to provide the nutrients most limited in the diets of women and children—protein, calcium, vitamin A, and vitamin C. To date, the only fruits and vegetables provided have been juice (for all participants older than 4 months) and fresh carrots for breastfeeding women. An evaluation of nutrition education within the WIC program to increase the consumption of fruits and vegetables in Maryland 13 showed that compared with control participants, intervention participants increased intake by more than one half serving a day on average. Predictors of increased consumption included the number of nutrition education sessions attended, ethnicity, education, and self-efficacy. 13 There has been considerable discussion about adding fruits and vegetables to the WIC supplemental food “package.” A recent report by the Institute of Medicine recommended a number of changes, including the addition of fruits and vegetables to the packages for all participants older than 6 months. 14 The food package for postpartum women at the time we conducted our study included fluid milk, cheese, eggs, iron-fortified cereal, fruit juice, and for breastfeeding women, canned tuna and fresh carrots. We sought to determine whether an additional economic subsidy for fresh fruits and vegetables for postpartum WIC participants would result in increased consumption of fruits and vegetables. We tested the hypothesis that effective and sustained improvement in fruit and vegetable intake would result from improved economic access to fresh produce for a 6-month period.
