More than 20% of US children ages 2-5 yrs are classified as overweight or obese. Parents greatly influence the behaviors their children adopt, including those which impact weight (e.g., diet and physical activity). Unfortunately, parents often fail to recognize the risk for excess weight gain in young children, and may not be motivated to modify behavior. Research is needed to explore intervention strategies that engage families with young children and motivate parents to adopt behaviors that will foster healthy weight development.
This study tests the efficacy of the 35-week My Parenting SOS intervention. The intervention consists of 12 sessions: initial sessions focus on general parenting skills (stress management, effective parenting styles, child behavior management, coparenting, and time management) and later sessions apply these skills to promote healthier eating and physical activity habits. The primary outcome is change in child percent body fat. Secondary measures assess parent and child dietary intake (three 24-hr recalls) and physical activity (accelerometry), general parenting style and practices, nutrition- and activity-related parenting practices, and parent motivation to adopt healthier practices.
Testing of these new approaches contributes to our understanding of how general and weight-specific parenting practices influence child weight, and whether or not they can be changed to promote healthy weight trajectories.
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Preventing obesity in children requires intervening early, before a child becomes overweight and an unhealthy weight gain trajectory is established. Current estimates from the US indicate that even among the youngest children, those aged 2-5 years, more than 20% are already overweight or obese [
Despite the alarming prevalence of overweight in children and the health risks associated with excess weight, prevention of child obesity is not a seen as a priority for many parents. This remains the case in spite of widespread understanding among professionals that obesity prevention efforts must engage parents who are the key gatekeepers that shape the social and physical environment of the home, and, as a result, influence their child's diet and physical activity behaviors [
Given the critical need to educate parents about their role as gatekeepers in the prevention of obesity, it is surprising that relatively little empirical attention has been devoted to intervening in families with preschool-age children before unhealthy nutrition and physical activity patterns have been entrenched [
In order to create an intervention for parents of preschool-age children that promotes healthy weight gain, it was important first to understand the family context and how it influences child weight and weight-related behaviors, as well as how to motivate behavior change in both parents and children. Darling and Steinberg's Integrative Model of Parenting provides a conceptual model for understanding the family system and how parent variables (values, parenting style, and parenting practices) affect child behavior [
Ryan and Deci's Self-Determination Theory provides a framework for understanding motivations, and suggests approaches for building intrinsic motivation to adopt healthier behaviors [
These two theoretical models serve as the basis for the current conceptual model for the parenting for healthy weight intervention described below (Figure
This study uses a randomized control design to test the efficacy of
The study's primary hypothesis is that, by the end of the 35-week intervention, children in the intervention arm will have a lower mean change in percent body fat compared to children in the control arm. Secondary hypotheses include: that, in comparison to children in the control arm, children in the intervention arm will: (1) improve the quality of their dietary intake, (2) increase their physical activity, and (3) maintain a lower mean percent body fat following a 6-month, no-treatment maintenance period. We also hypothesize that parents in the intervention arm, in comparison to those in the control arm, will: (1) improve the quality of their dietary intake, (2) increase their physical activity, and (3) improve their general parent behaviors (i.e., general parenting style and practice) as well as domain-specific practices around feeding and activity. In addition, we will examine the mediating effects of parent motivation, general parenting style and practices, and parenting for healthy weight on the impact of the 35-week parenting intervention on child diet and physical activity behaviors and body fat; although due to the exploratory nature of this aim no hypotheses are offered.
Families with preschool-age children are being recruited in three waves using a variety of community resources including child care centers, direct mailings, community bulletin boards, listservs, and newspaper community announcements. The recruitment plan incorporates strategies to engage families from diverse racial, ethnic and socioeconomic backgrounds. For example, recruitment efforts are focused on counties located in central North Carolina with a large percentage of minority residents. Additionally, child care centers that accept subsidies are specifically targeted to engage low-income families.
Interested families are screened by phone. Eligibility criteria include having at least one child between the ages of 2 and 5 years old, at least one parent with a body mass index (BMI) greater than 25 (based on self-reported height and weight), willingness to participate in measures and intervention activities, and ability to speak English or comprehend standard age-level materials. Signed consent is then obtained from all participants when they arrive for baseline data collection. Parents sign consent for their own participation and that of their child.
The study is powered on its primary outcome: mean change difference in child percent body fat, estimated from the Dezenberg et al. [
For each wave, participants are first stratified by income (household income more or less than $50,000) and county. Household income of $50,000 represents the approximate median household income for the counties targeted for recruitment and was therefore selected as the cut point for income stratification. For each wave and county combination, two randomization tables (one for each income level) are created using SAS 9.2 (SAS Institute, Cary NC) with a randomization allocation ratio of 1:1 and a block size of 2 to ensure balance between study arms across all strata. These randomization tables are then used to create sets of sequentially ordered cards that are sealed so that the condition assignment (control vs. intervention) appearing inside is not visible.
Participants have the opportunity to select a card and be randomized upon arrival to a kick-off event. For each wave, three to four kick-off events are offered. At the beginning of each event, cards from each of 2 stacks are placed into either pail "A" or "B", corresponding to income strata. The number of cards in the pail always exceeds the expected number of participants from each income stratum expected to attend the event. Cards in each pail are shuffled and as participants arrive, staff instruct participants to select one card from the appropriate pail. Cards remaining from the first event are left in the pails and used for the next event, with additional cards added as needed. Stratification procedures are not communicated to the participants.
At these kick-off events, families randomized into the intervention group immediately start their first session, while those randomized into the control group have a short child entertainment program (e.g., book reading, puppet show). Participants must complete baseline measures and attend one of these kick-off events in order to be randomized into the intervention or control group, and continue their participation in the study. This creates a run-in period and helps minimize loss to follow-up.
The
Formative and pilot work
| Date | Activity | Objectives |
|---|---|---|
| June 2004 - Jan 2005 | Focus groups with mothers of overweight children | Identify culturally specific child management concerns and behavioral intervention needs of parents and/or caregivers, and their preferences for intervention channels and modalities [ |
| Mar - May 2005 | Focus groups with AA mothers | Explore barriers to healthy nutrition and activity practices at home, collect impressions regarding a parenting for healthy weight intervention, and assess preferences regarding intervention delivery |
| Sept - Oct 2006 | Pilot of 4-part workshop series with parents from 1 local child care center | Examine the acceptability of a parenting for healthy weight workshop series and evaluate appropriateness of potential measures |
| Oct - Dec 2006 | Pilot of 3-part workshop series with parents from 6 local child care centers | Examine the feasibility of workshop delivery by trained facilitator (with a social work background) provided at the child care center |
The program is delivered through 12 in-person group meetings and 11 tailored phone calls across 35 weeks. The group meetings include separate programs for parents and their children.
The parent meetings are facilitated discussions about select parenting skills, and initial sessions address general parenting topics including: parenting style, child behavior management, stress management, coparenting relationships, and family routines. Later sessions show parents how to apply these skills to promote healthy nutrition and physical activity behaviors in their children. Table
Intervention overview
| Sessions | Key parenting messages | Nutrition/PA messages/activities |
|---|---|---|
| Stress management | • Identification of common parenting stressors | • Examples of ineffective coping strategy = using food/alcohol as source of comfort |
| Parenting style | • Introduction of 4 major parenting styles (authoritarian, authoritative, indulgent, uninvolved) | • Discuss strategies that parents with different styles might use to get their child to eat fruits and vegetables, and the pros and cons of each |
| Child management (2 sessions) | • Strategies for managing child behavior (attending, reinforcement and rewarding, effortful ignoring, setting clear rules and limits, choices, consequences, time out) | • Use of attending and verbal reward to encourage intake of healthy foods |
| Emotion regulation | • Improve understanding of how parents contribute to their child's emotional development through role modeling, their own response to their emotions, and their parenting behaviors | • Re-emphasize examples of ineffective and effective coping strategies and that children will learn these from their parents' example |
| Coparenting | • Strategies for strengthening the communication between coparents so that they can present a united front | • Encouraging parents to present a united front when it comes to healthy habits |
| Family routines | • Introduction to creating routines that can improve efficiency and predictability at home | • Planning time for healthy meals should be part of morning and evening routines |
| Nutrition and feeding practices | • Routines can help parents find the time to plan, prepare, and eat meals as a family | • Introduction to the food guide pyramid |
| Physical activity and activity practices | • Planning ahead can help parents make the time for family activity | • Introduction to physical activity guidelines for adults and children |
| Sleep habits | • Creating bedtime routines can help parents get children to bed with fewer battles | • Sleep recommendations for children and adults |
The child program grew out of our pilot work where parents indicated that a program beneficial to their child, rather than just offering child care, would provide additional motivation for their own attendance. The child program is designed to reinforce the parent program and prepare children for changes they would be seeing at home related to new parenting practices and the encouragement to eat healthy and be active. Each session follows a set routine that incorporates active play time, a family-style meal, a music and movement game, an enrichment activity, a new food taste testing, and story time. Specific games, activities, and books are selected to reinforce that week's key lesson. Lesson topics include: rules and limits, emotions, working as a family and family routines, and healthy lifestyles.
Families randomized into the control group are enrolled into a child's book club. The child entertainment program offered at kick-off events is intended to help launch the book club program and is generally conducted by local librarians. Families receive one book each month, mailed directly to their home, for the duration of the 35-week intervention period. Book titles for this arm were identified with the assistance of a child's librarian. Books related to health, nutrition, and physical activity were purposefully avoided when selecting titles. Mailing of books directly to participants' homes also helps monitor for changes of address among control families.
Outcomes are assessed at three time points: baseline, post-intervention, and maintenance (6-month post). Measurement events are scheduled at convenient community locations so that participating families can come in and complete measurements. Locations allow for multiple stations including check-in, anthropometric measures, parent psychosocial surveys, accelerometry, and check-out. Locations also provide space for child activities to keep children entertained while parents complete surveys.
The primary outcome is mean change difference in child percent body fat between baseline and post-intervention. Percent body fat is calculated using the formula of Dezenberg et al.[
Standing height and weight are measured by a trained technician on both children and parents. Height is measured to the nearest 1/8 inch with a Shorr or Seca infant/child/adult measuring board (Shorr Productions, Olney, MD; Seca Corporation, Columbia, MD); and weight is measured to the nearest 0.1 lb with a Seca model 770 portable electronic scale (Seca Corporation, Columbia, MD). Additional anthropometric measures taken on children are triceps and subscapular skinfold thickness and waist circumference. Skinfold thicknesses are measured to the nearest 1.0 mm using Lange calipers (Beta Technology, Inc. Cambridge, MD); and waist circumference is measured to the nearest 0.1 cm using a Gulick II measuring tape. These measures are also used to calculate child and parent BMI, child BMI z-score, and child sum of two skinfolds.
Parent and child diet are assessed using three days (2 weekdays and 1 weekend day) of unannounced 24-hour dietary recalls collected over a 4-week period. All recalls are conducted under the direction of the UNC Nutrition Epidemiology Core (CNRU, NIH DK056350) using traditional multi-pass procedures which provide cues for portion size, use of condiments, etc. [
Parent and child physical activity are assessed with ActiGraph GT3X accelerometers (ActiGraph, LLC, Fort Walton Beach, FL). Parent monitors are programmed to collect data in 1-min epochs, while child monitors use a 15-sec epoch to capture their variable movement patterns. Monitors are worn over the right hip, for seven consecutive days, during waking hours, except when in water. Data are reduced using the adapted SAS code used in NHANES, and appropriate cut-points are applied to determine time spent in sedentary, light, moderate, and vigorous physical activity. We will use the current NHANES accelerometer cut-points used for parent data [
Existing scales are also employed to measure parent practices addressed as part of the intervention, including: (1) the Alabama Parenting Questionnaire - Preschool Revision (APQ-PR), which includes subscales for positive parenting, inconsistent parenting, and punitive parenting [
Parent feeding style and behaviors are assessed using a combination of items from existing instruments including: (1) the Caregiver's Feeding Style Questionnaire (CFSQ), which assesses two dimensions of parent feeding - demandingness and responsiveness) [
Measures of parent practices specific to physical activity are not well developed; therefore, a tool was developed by investigators based on an extensive literature review (unpublished data) and using items and scales taken or modified from existing instruments [
Given the inclusion of the Self-Determination Theory Framework in our conceptual model, measures of intrinsic/autonomous motivation to change behavior are also assessed. Autonomous motivation to change is assessed with the Treatment Self-Regulation Questionnaires (TSRQ), which measures controlling vs. autonomous reasons an individual has for adopting certain healthy behaviors [
Several other variables thought to be related to the primary constructs of interest are assessed, including parenting stress (Parenting Stress Index [
Descriptive statistics will be used to compare the demographic characteristics of intervention and control arm participants at baseline - medians for continuous variables and proportions for categorical variables. All statistical tests and exploratory and confirmatory factor analyses on the physical and parenting and child psychological measures will be performed with either SAS 9.2 (SAS Institute, Cary NC) and MPlus [
An intention-to-treat approach will be used for the primary hypothesis: the comparison of the mean change difference in child percent body fat from baseline to post-intervention between intervention and control children. We expect that our intervention will be effective in producing an absolute difference in change in percent body fat of 2%-3% between the two arms at post-intervention (35 weeks), but power was calculated based on the less optimistic 2% and with a conservative two-sided test of significance.
The Parenting SOS program offers an innovative approach to addressing healthy weight development in families with preschool-age children. The intervention is based on considerable formative and pilot research, and addresses general parenting as the gateway activity for parents to develop appropriate parenting skills for their children's healthy eating and activity patterns. Responding to our formative data, we developed a companion child program that offers our families support in making changes to current lifestyle practices. In addition to the innovative intervention content, the Parenting SOS program is theory-driven based on Self-Determination and Social Cognitive theories.
Because of the pioneering nature of this study, we include numerous measures of the social, environmental, and behavioral components of family life in anticipation to increase our understanding of the factors that moderate and mediate healthy weight parenting behaviors and, ultimately, child body fat development.
The authors declare that they have no competing interests.
DW is the principal investigator; she led the conception and design of the study, development of the intervention, selection of primary and secondary measures, and development of the manuscript. AV provides project management and coordination; she has contributed to the development of the intervention, selection of measures, and assisted with the development of the initial manuscript draft and incorporated revisions from co-investigators. KB provides biostatistical oversight for the study; he has contributed to the study design, calculation of power, development of randomization strategies, and has critically reviewed and edited the current paper. MC contributed to the development of the intervention and behavior change strategies, and reviewed/approved the manuscript. DJ contributed to the development of the intervention, identification of measures related to general parenting style and practices, and participated in the writing and editing of the current manuscript. AP provided guidance on data analysis strategies particularly plans for meditational analysis, assistance in selection of appropriate measures, and critically reviewed and edited the current paper. JS contributed to the development of the study design, selection of measures and randomization strategies, provided guidance on the scope of the manuscript, and has critically reviewed and edited the current paper. All authors have reviewed and approved the current version of the manuscript.
The pre-publication history for this paper can be accessed here:
This paper is part of a projected funded by the National Heart, Lung, and Blood Institute (R01 1HL091093) and is conducted with support from the Nutrition Obesity Research Center at the University of North Carolina at Chapel Hill (NIH DK056350). The work was done at the UNC Center for Health Promotion and Disease Prevention, a member of the Prevention Research Centers Program of the Center for Disease Control and Prevention (CDC) (#U48-DP000059). The content is solely the responsibility of the authors and does not necessarily represent the official views of the CDC. In addition to these sponsors, we would like to acknowledge the work of Laura G. McKee, PhD, who contributed to the development of the program during her post-doctoral fellowship in the Department of Psychology at the University of North Carolina at Chapel Hill. Additionally, we would like to recognize the efforts of Josephine Emunah, MPH, who assisted with development of the intervention program and serves as the sole interventionist for our project.