Abstract
Objective
To evaluate the impact of a Special Supplemental Nutrition Program for Women, Infants, and Children (WIC)-based intervention on the food and beverage intake, physical activity, and television watching of children ages 1-5.
Design
Longitudinal surveys of intervention and control participants at baseline, 6 months, and 12 months.
Results
Analysis of variance tests showed that the intervention had a small but significant impact on TV watching and fruit intake. The intervention was most protective for children younger than 2 years of age.
Conclusions and Implications
Although the impact of the intervention was relatively small and limited to the youngest children served by WIC, findings suggest that the WIC setting is appropriate for improving healthful behaviors that are linked to reducing the rates of early childhood overweight.
Key Words
Introduction
Early childhood overweight is a growing concern, and the overweight rates of 2- to 5-year-old children have risen dramatically in recent years.
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There has been nationwide interest in interventions that focus on the reduction of overweight in children and adults,National Center for Health Statistics. Health, United States, 2008, With Chartbook. Hyattsville, MD: National Center for Health Statistics. http://www.cdc.gov/nchs/data/hus/hus08.pdf#070. Published 2009. Accessed November 3, 2009.
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but few have focused specifically on preventative strategies in children under the age of 5. In addition, many interventions use methodologies that, although important in demonstrating impact, are not sustainable beyond the period of the intervention. This study describes the impact of an individual nutrition education intervention that focused on the prevention of early childhood overweight in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) setting.The WIC funded by the United States Department of Agriculture (USDA) is a nutrition program for pregnant, breastfeeding, and postpartum women; infants; and children under the age of 5 who are low income (up to 185% of the federal poverty level) and at nutritional risk. Created in 1974, the program was designed to address hunger in the United States (US). With the recent improvement to the WIC food package, the WIC program is now being viewed as having high potential in obesity prevention efforts.
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One of the core services of the WIC program is quality individual nutrition education for all families.6
About half of all US children under age 5 receive services and supplemental food from the WIC program at some time,US Department of Agriculture, Food and Nutrition Service. Revitalizing quality nutrition services in WIC. http://www.fns.usda/wic.CONTENT/RQNS/RQNS.htm. Accessed November 5, 2009.
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thus low-cost interventions that prove successful in the WIC setting have the potential to reach the majority of low-income families in the nation.One previous study concluded that the traditional dialog between WIC staff and participants is not increasing mothers' awareness of the problem of obesity in their children.
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It has been suggested that the WIC program should provide staff training in counseling skills to elicit participants' personal goals.8
Furthermore, there has been increased interest in incorporating Motivational Interviewing (MI) counseling strategies into WIC-based counseling,6
and evidence that MI strategies can be helpful in the treatment of childhood obesity.US Department of Agriculture, Food and Nutrition Service. Revitalizing quality nutrition services in WIC. http://www.fns.usda/wic.CONTENT/RQNS/RQNS.htm. Accessed November 5, 2009.
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This study was designed to draw on these findings and examine whether WIC-based education specifically designed to prevent early childhood overweight could be effective when administered as part of standard individual education for WIC participants. The primary goal of the intervention was to influence the food and beverage intake, physical activity, and/or television watching of children ages 1 to 5 via one-on-one education between WIC staff and the primary caregiver. There is growing literature that rapid weight gain in infancy and the first 2 years of life is a significant risk indicator for later adiposity.10
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Thus, it was of interest to examine whether caregivers with infants and toddlers under age 2 might respond differently to intervention than caregivers of children older than 2.Methods
Intervention
The Child Health and Intervention Research Project (CHIRP) was a collaborative project between University of California, Los Angeles (UCLA) and the Public Health Foundation Enterprises Special Supplemental Nutrition Program for Women, Infants, and Children (PHFE-WIC) program, the largest local agency WIC program in the nation, serving over 225,000 families monthly in Los Angeles and Orange Counties, CA. Funded by USDA, CHIRP included a WIC-based intervention that was a simple enhancement of core WIC individual education. As part of the eligibility requirement for the WIC program, WIC children are recertified every 6 months to maintain program participation. Recertification entails income and address verification, updating of medical information, and one-on-one participant education on a nutrition or health topic. From October 2007 to June 2009, the CHIRP intervention was provided every 6 months to the caregivers of all children ages 1-5 years during usual WIC recertification appointments at 1 WIC site in Pomona, CA. Like all WIC services at this location, the intervention was provided in English or Spanish.
Embedded within the routine WIC individual nutrition education, the CHIRP intervention included an enhanced WIC child questionnaire, on which caregivers reported information about their child's food and beverage intake, physical activity, and television watching, and a one-on-one dialog between the WIC staff member and participant. To guide the dialog, a menu of 6 predetermined topics was available for discussion: (1) choosing yummy vegetables and fruit; (2) choosing healthy beverages; (3) watching less television; (4) getting up and moving more; (5) choosing small, healthy, and fun snacks; and (6) a blank option for the participant in case the caregiver chose a topic different from those listed (Kibbe D, oral communication, 2007).
Prior to the start of CHIRP, WIC staff members from the intervention site received training to apply MI techniques in their individual education sessions. This training was similar to the MI training that was scheduled at all of the other 58 PHFE-WIC sites, but the intervention site was prioritized to be among the first sites trained. Motivational Interviewing techniques encourage participants to express thoughts, feelings, and ambivalence so they can choose what to change and agree on a change plan.
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For the CHIRP intervention, based on stages of change theory of the transtheoretical model, each participant completed the WIC child questionnaire and reviewed it with the WIC staff person. The participant then chose a discussion topic from the menu of options, and the WIC staff member engaged the participant in a dialog about the topic as it related to his or her child, asking the participant to share current behaviors on the topic. At the end of the dialog, the participant was asked to decide on a change goal for the next 6 months (eg, limit the child's consumption of juice to no more than 4 ounces per day). Participants were asked to rate their readiness for change on a number ruler. The intervention was repeated every 6 months at the child's recertification appointments, and the participant was able to choose the same topic or a different topic at subsequent visits.A CHIRP database was designed to aid the staff in tracking the participant's topic choices, goals, and readiness for change over time. In addition to the tracking documentation, the CHIRP database also provided the staff with a script of open-ended MI questions and information to offer during the counseling. The scripts were linked to each of the 5 education options and were piloted by staff members and participants prior to study commencement.
Study Design and Research Sample
The primary goal of CHIRP was to influence the child's food and beverage intake, physical activity, and/or television watching. To evaluate the impact of the intervention on outcomes, a matched control site was chosen where the staff had not yet been trained in MI techniques and did not focus individual nutrition education on topics specific to obesity prevention. The control WIC site, located approximately 25 miles from the intervention site, was chosen from the 57 remaining PHFE-WIC sites based on its match to the intervention site in caseload size (serving about 7,000 participants/month), staffing (about 11 staff members per site), and ethnic composition of WIC participants (91% Latino).
The CHIRP intervention commenced in October 2007 at all recertification appointments of 1- to 5-year-old children at 1 WIC site. Over the course of the study, over 7,000 caregivers received the CHIRP intervention. At the intervention site, the first 412 caregivers completing a recertification appointment for their 11- to 38-month-old child were recruited to participate in a research study to evaluate the impact of WIC individual nutrition education. Study participants completed a 6-page survey before they received their first CHIRP individual education encounter. At the control site, the first 409 caregivers completing a recertification appointment for their 11- to 38-month-old child were recruited to participate in the research and completed the 6-page survey prior to their usual WIC counseling session. A sample size of 400 per group was needed to maintain at least 280 per group at 12 months. All research protocols were approved through full review by the UCLA Institutional Review Board, and all participants reviewed and signed a consent form prior to completing the baseline survey that included consent for follow-up phone surveys.
The surveys were largely identical at the 3 time points, and the 6- and 12-month phone surveys included questions about the WIC counseling that were not relevant for inclusion at baseline. Surveys included multiple choice and Likert scale questions about the child's food and beverage intake, physical activity, and television watching, as well as questions about whether caregivers were trying to make changes in any of these behaviors (eg, trying to offer more vegetables to their child; trying to reduce the amount of television their child watched). Because the survey questions needed to measure the designed intervention, previously validated instruments were not appropriate for use. Therefore, many questions were used that had been developed in previous work with this population,
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and these questions were modified to fit with the CHIRP intervention topics. Many questions were taken from the standard WIC child questionnaire. The final version of the survey was piloted in English and Spanish prior to study commencement, and participants reported the questions were easy to understand and answerable.Data Analysis
All survey data were entered into Microsoft Excel (Microsoft Corporation, Redmond, WA, 2003) and downloaded to SPSS (version 15.0, SPSS Inc., Cary, NC, 2006) for analysis. Parental report of children's health behaviors were examined as outcome variables, which included daily hours spent watching TV, number of times a day eating fruit, vegetables, sweet and salty snacks; number of times a day drinking sweetened beverages and water; and number of days per week with more than 60 minutes of physical activity. Analysis of variance (ANOVA) analyses were used to test the effect of intervention. Analyses were considered significant at P < .05.
Results
Participant Characteristics
Participants in both the intervention and control groups completed surveys by phone 6 months (total n = 680) and 12 months (total n = 589) post-baseline with WIC administrative staff blind to the research hypotheses. All intervention participants who remained in the sample at 12 months had received a total of 3 intervention contacts. The 6-month follow-up survey primarily served the purpose of maintaining contact with caregivers, and the data were not used in the current analysis. The 28% attrition from baseline to 12 months was a result of participants moving (n = 87, 11%), missing their WIC appointment (n = 59, 7%), or being unreachable for follow-up (n = 56, 7%), declining to be part of the follow-up (n = 17, 2%), over income to continue WIC participation (n = 10, 1%), or aging out of WIC (n = 2, <1%) Phone surveys lasted about 30 minutes, and study participants were mailed a $5 gift card for their time to complete each phone survey.
The demographic characteristics of the intervention and control groups were highly comparable (see Table 1). Two hundred ninety-two families from the intervention group and 297 from the control group remained in the study and completed both the baseline and 12-month surveys. The attrition rates were therefore comparable at 29% for the intervention group and 27% for the control group. As is typical of the WIC population in southern California, most of the caregivers in the study were Latino, with nearly half born in the US. The average mother had some high school education and did not work outside the home.
Table 1Sample Characteristics of the Intervention and Control Groups at Baseline
| Intervention Group (n = 412) | Control Group (n = 409) | |
|---|---|---|
| Child's characteristics | ||
| Sex, male (%) | 49 | 52 |
| Age (mo) | 23 ± 9.2 | 22 ± 9.0 |
| Mother's characteristics | ||
| Ethnicity (% Latino) | 93 | 94 |
| Born in the US (%) | 43 | 44 |
| Preferred language (% English) | 47 | 43 |
| Education (y) | 11 ± 3.1 | 11 ± 3.4 |
| Employed (%) | 29 | 30 |
mo indicates months; y, years.
Note: no significant difference (P < .05) found between groups in the above table.
Participants' reported health behaviors from baseline and 12-month follow-up are presented in Table 2. Overall, participants in both groups demonstrated fairly healthful habits during baseline. On a typical day, children ate fruits and vegetables about 5 times, watched 2 hours of TV, drank sweetened beverages once, ate sweets or salty snacks once, and were physically active 4.5 days of the week. Independent t test showed no significant difference between the intervention and control groups on any outcome measures at baseline.
Table 2All Child Participants' Health Behaviors as Reported by Their Parents at Baseline and 12-month Follow-up
| Intervention Group (n = 292) | Control Group (n = 297) | |||||||
|---|---|---|---|---|---|---|---|---|
| Baseline | 12 Months | Baseline | 12 Months | |||||
| M | SD | M | SD | M | SD | M | SD | |
| TV watching (h/d) | 2.3 | 1.4 | 2.6 | 1.4 | 2.3 | 1.4 | 2.9 | 1.4 |
| Fruit intake (times/d) | 3.0 | 1.4 | 2.7 | 1.2 | 3.1 | 1.4 | 2.5 | 1.2 |
| Vegetable intake (times/d) | 2.6 | 1.3 | 2.1 | 1.2 | 2.7 | 1.4 | 2.0 | 1.1 |
| Eating sweet or salty snacks (times/d) | 1.2 | 0.9 | 1.4 | 1.0 | 1.2 | 1.0 | 1.5 | 1.0 |
| Drinking sweetened beverages (times/d) | 1.1 | 1.2 | 0.9 | 1.0 | 1.1 | 1.2 | 1.0 | 1.2 |
| Drinking water (times/d) | 3.8 | 1.6 | 3.6 | 1.6 | 3.9 | 1.6 | 3.5 | 1.6 |
| More than 60 min of physical activity (d/wk) | 4.5 | 2.4 | 6.0 | 1.7 | 4.4 | 2.5 | 5.9 | 1.8 |
d indicates day; h, hours; M, mean; SD, standard deviation; wk, week.
a A significant main effect of intervention (P < .05), as indicated by analysis of variance.
Test of Intervention Effect
From baseline to 12-month follow-up, health behaviors shifted in both positive and negative directions. Analysis of variance tests were used to analyze the effect of intervention on 12-month results of the child's food and beverage intake, physical activity, and television watching, while controlling for the child's age group (younger or older than 2 years), language (English, Spanish), mother's education, and baseline result. A significant effect of intervention was found for TV watching (F1,545 = 5.65, P < .05) and fruit consumption (F1,545 = 6.5, P < .05), but not the others. The intervention explained about 1% of the variance for these 2 outcomes.
Child's age was found to have a significant main effect and interaction effect for a number of the outcome variables. To further tease apart the relationship between child's age and intervention, 2 additional sets of ANOVA analyses were conducted: one for children younger than 2 years at baseline, and one for children older than 2 years at baseline. The control variables in these analyses included mother's education, language, and baseline result.
Younger Children (< 2 years)
Analysis revealed that intervention had a significant main effect on hours of TV watching (F1,304 = 3.8, P < .05), frequency of drinking water (F1,306 = 4.2, P < .05), and eating vegetables (F1,298 = 3.7, P = .05) and marginal significance for fruit (F1,305 = 2.9, P = .09). Children in the control group watched more TV, drank less water, and ate fewer vegetables and fruit, whereas children in the intervention group maintained levels closer to baseline (for group mean see Table 3). No significant effect was found for sweetened beverages, snacks, and physical activity.
Table 3The Significant Effect of Intervention on Younger (< 2 years old) Participants' Health Behaviors
| Intervention Group (n = 154) | Control Group (n = 176) | |||||||
|---|---|---|---|---|---|---|---|---|
| Baseline | 12 Months | Baseline | 12 Months | |||||
| M | SD | M | SD | M | SD | M | SD | |
| TV watching (h/d) | 2.0 | 1.5 | 2.4 | 1.5 | 2.0 | 1.3 | 2.8 | 1.4 |
| Fruit intake (number of times/d) | 2.8 | 1.3 | 2.7 | 1.3 | 3.0 | 1.5 | 2.6 | 1.2 |
| Vegetable intake (number of times/d) | 2.5 | 1.3 | 2.3 | 1.2 | 2.7 | 1.5 | 2.0 | 1.2 |
| Drinking water (number of times/d) | 3.7 | 1.6 | 3.8 | 1.6 | 3.8 | 1.7 | 3.6 | 1.5 |
d indicates day; h, hours; M indicates mean; SD, standard deviation; y, years.
Note: All significant (P < .05), as indicated by analysis of variance.
Older Children (≥ 2 years)
A significant intervention effect was found only for fruit consumption (F1,240 = 4.8, P < .05), with the intervention group eating more fruit than the control group at 12-month follow-up.
Discussion
Results from this study suggest that intervention efforts may be most effective in the early years of infant and child feeding. A WIC-based intervention designed to change behaviors known to relate to early childhood overweight does not appear to yield dramatic results for all children served by WIC, but it has some impact when targeted to younger children (11-24 months). It appears this low-intensity intervention was able to keep parents on track with the healthful behaviors they started when feeding young children. The period from 6-24 months is a critically important feeding transition from breast milk and/or infant formula to solid food, and it appears to be a time that caregivers are most responsive to messages related to feeding their children.
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The intervention appears to have helped caregivers maintain healthful behaviors with their younger children, protecting against increases in some behaviors linked to early childhood overweight. Thus, the intervention did not improve caregiver behaviors that were already at fairly healthful levels at baseline, but it appears to have had a protective effect, helping caregivers of children under age 2 maintain more healthful behaviors with their child, whereas the control group worsened. The magnitude of the effect of the intervention is on par with the relatively low dose of intervention, 1 counseling session in the WIC setting every 6 months. The intervention was designed to fit within the current WIC setting such that it could be sustainable beyond the period of the supplemental grant funds. Extra incentives for the 7,000 intervention participants were intentionally excluded, and the dose was set to match the usual WIC recertification periods for children, thus the impact of the intervention was not as large as when providing incentives or more frequent intervention.
Although the results of this study are applicable to the very large WIC population served in southern California, findings may not extend to WIC populations in other regions, where the racial-ethnic background of the population differs. Results may extend to other Latino populations, but the impact of the WIC-based intervention must be further evaluated. It is also important to note that both groups reported fairly healthful behaviors at baseline. Although this may be a function of the self-report methodology employed in this study, it may also be that WIC participants engage in fairly healthful behavior. The fact that both groups reported similar behaviors at baseline suggests that neither group was differentially influenced by the self-report methodology. The sample size of this study did not allow for examination of how the dose of individual topic dialogs (eg, TV, fruits and vegetables) influenced outcomes. Future examinations of the 7,000 participants who completed the intervention are intended to shed light on this important question. Finally, this study took place before the October 2009 WIC food package change, thus the change in fruit consumption cannot be attributed to the recent inclusion of fruit in the food package.
Implications for Research and Practice
Although the impact of the intervention was small and limited to the youngest children served by WIC, findings suggest that the WIC setting is appropriate for improving healthful behaviors that are linked to reducing the risks of pediatric overweight. Caregivers with children under age 2 may be particularly responsive to intervention. WIC staff members may be more successful in encouraging behavior change in caregivers and their children when partnerships are built with the pediatric community and other organizations who work with the WIC population.
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Acknowledgments
This study was supported by USDA/CSREES Grant # 2005-35215-16075. We gratefully acknowledge Patricia Crawford for her significant contributions to this research.
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Footnotes
The authors have no conflict of interest to report with the sponsor of this supplement article or products discussed in this article.
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Copyright
© 2010 Society for Nutrition Education. Published by Elsevier Inc. All rights reserved.
