If you don't remember your password, you can reset it by entering your email address and clicking the Reset Password button. You will then receive an email that contains a secure link for resetting your password
If the address matches a valid account an email will be sent to __email__ with instructions for resetting your password
Address correspondence to: Norma Olvera, PhD, Health Program, Educational Psychology Department, University of Houston, 491 Farish Hall, Houston TX 77204-5029
The development of effective obesity interventions to reduce adiposity indicators in Latina girls is a public health priority because of their increased risk for becoming overweight. Research indicates that the summer season may be a critical time to intervene because summer exacerbates children's risk for excessive weight gain and increased body fat development.
Purpose
The purpose of this study was twofold: (1) to determine if summer and follow-up interventions reduce adiposity in Latina girls; (2) to assess if such interventions reduce adiposity in Latina girls after controlling for their mothers' adiposity measures.
Design
This study had a non-experimental (one-group pre- and multiple post-intervention assessment) design. Following a 4-week healthy-lifestyle summer program, each mother–daughter pair participated in 12 weekly follow-up sessions.
Setting/participants
The sample consisted of 61 pairs of Latina girls and their mothers (N=122). Daughters' average age was 10.9 years (±1.6 years) and mothers' average age was 38.0 years (±1.6 years). All daughters and 92% of the mothers were categorized as overweight/obese.
Main outcome measures
Percent body fat (%BF), abdominal fat, and height and weight measurements to calculate BMI were conducted at pre-intervention (M1 [baseline]) and three post-intervention time points (M2 [Month 2]; M3 [Month 3]; and M4 [Month 6]). Paired sample t-tests were used to assess the differences in adiposity among the daughters from M1 to M4. Repeated-measures ANCOVA tests were used to control for mother's adiposity.
Results
Reductions of %BF (p<0.001); abdominal fat (p<0.05); and BMI (p<0.001) at M2 were found for the summer intervention, but no effects were found at M4. Maternal %BF, abdominal fat, and BMI did not have an impact on the daughters' adiposity indicators.
Conclusions
Results from this study revealed that a summer intervention appears to be effective in reducing adiposity in Latina girls, but the follow-up sessions did not result in sustaining continued reductions. Maternal measures did not influence their daughters' adiposity measures.
Introduction
Childhood obesity is a major health problem in the U.S.
The development of interventions to combat childhood obesity has become a public health priority. Recent studies indicate that physical activity interventions may be effective in reducing body fat (percent body fat and abdominal fat) among children.
Preliminary findings of the effect of a 3-year after-school physical activity intervention on fitness and body fat: the Medical College of Georgia Fitkid Project.
These studies suggest that it is important to focus on body fat because it is more closely associated with cardiovascular and metabolic risk factors than is BMI.
BMI estimation on school-aged populations also raises a host of questions related to validity, including a lack of sensitivity to increases in lean mass as a result of physical training. BMI also does not differentiate between healthy, fat-free mass, fat mass, and rapid physical maturation.
Increasing the physical activity of Latino children is a public health priority, given that they are at increased risk for inactivity. Several studies report that Hispanic and non-Hispanic black children are less active than non-Hispanic white youth.
Asthma and maternal body mass index are related to pediatric body mass index and obesity: results from the Third National Health and Nutrition Examination Survey.
have suggested a novel approach to family-based intervention that targets natural interactions that occur across generations of women within a family, such as mother–daughter pairs who share similar habits and beliefs. These kinds of interventions may be synergistic and cost effective in the prevention and treatment of obesity.
Research also indicates that the summer season may be a critical time to intervene because summer exacerbates children's risk for excessive weight gain and increased body fat development.
Non-Hispanic black and Hispanic children, as well as overweight children, seem to be particularly vulnerable to increases in weight gain and body fat during this time.
Rodriguez AX, Olvera N, Leung P, et al. Association between the summer season and body fatness and aerobic fitness among Hispanic children. J Sch Health. Accepted.
Despite evidence indicating that summer is a critical period for increased adiposity in minority children, a paucity of obesity interventions targeting minority children have been conducted during this time period.
Only two pilot studies have been identified. A study by Baranowski et al.
revealed a nonsignificant trend in reduction of BMI and body fat in African-American girls (aged 8–10 years) who participated in an 8-week summer obesity intervention followed by 12 weekly follow-up sessions. Olvera et al.
reported reductions in BMI, waist circumference, MVPA, and fitness in minority girls (aged 9–14 years) who participated in an intense 3-week intervention named BOUNCE (Behavior Opportunities Uniting Nutrition Counseling and Exercise). The BOUNCE intervention included primarily a group-structured exercise component followed by behavioral counseling and nutrition education with limited parental involvement. Overall, findings from these two studies suggest that the summer season offers a promising time for reducing adiposity in minority children.
Building on prior work, the purpose of the present study was twofold. The first goal was to determine if there is a reduction in adiposity indicators in Latina girls after their participation in an intense, 4-week BOUNCE summer intervention followed by 12 weekly ReBOUNCE follow-up sessions. The rationale for a 4-week BOUNCE summer intervention is supported by a study by Kellam et al.,
which compared a 3-week versus 4-week BOUNCE intervention and found that the latter intervention was more effective in eliciting minutes of MVPA than a 3-week BOUNCE intervention. The effectiveness of 12 weekly follow-up sessions was also assessed, because research has shown that booster sessions after an intervention are beneficial to sustain behavior change.
The second goal was to assess if the BOUNCE intervention reduces adiposity in Latina girls, after controlling for their mothers' adiposity measures.
In the current study, the following research questions were asked: (1) What changes in adiposity indicators (percent body fat, abdominal fat, and BMI) are observed in Latina girls participating in the BOUNCE intervention across four time points conducted at pre-intervention baseline (M1) and three post-intervention time points (M2 [Month 2]; M3 [Month 3]; and M4 [Month 6]); (2) Will the BOUNCE intervention reduce adiposity indicators in Latina girls after controlling for their mothers' adiposity measures?
Methods
Study Design
This is a non-experimental single-group study with data collected at baseline and later again at 2, 3, and 6 months.
Setting and Participants
The sample consisted of 61 pairs of Latina girls and their mothers (N=122) recruited across two different cohorts (2009 and 2010; Figure 1). The daughters' mean age was 10.9 years ± 1.6 years and the mothers' mean age was 38.0 years ± 6.5 years. Study inclusion criteria consisted of girls being (1) aged 9–14 years; (2) self-described as Hispanic/Latina; (3) overweight (BMI ≥85th percentile) or obese (BMI ≥95th percentile); and (4) free from physical activity restrictions that would limit active participation in the current study as certified by a medical professional.
Figure 1Timeline of intervention and data collection
Participants were recruited primarily through referrals by school nurses, teachers, and community outreach coordinators. Before baseline measurements, daughters were asked to sign assent forms and mothers were asked to sign a consent form. The University of Houston Committee for the Protection of Human Subjects approved the research protocols and assent/consent forms.
Intervention
Summer intervention
The 2009 and 2010 BOUNCE summer interventions were delivered to daughters from 9am to 5pm, Monday through Friday, during the entire month of July. Each BOUNCE day commonly consisted of three to four exercise sessions, one nutrition education session, one behavioral counseling session, as well as two healthy snacks (100 calories each) and a healthy lunch (500 calories). A typical BOUNCE day started with a flexibility session followed by a sports skills session or games session. Lunch and a nutrition lesson were then followed by a traditional fitness session. Following a counseling session, the day would end with a dance session.
Because the BOUNCE summer intervention is primarily an exercise intervention, the next section expands on the BOUNCE exercise component. The BOUNCE exercise program consisted of group physical activity sessions of varied intensity based on Ridley's compendium for energy expenditure in youth (light=2 METs; moderate=3–5 METs; vigorous=≥6 METs; Table 2).
Each of the BOUNCE cohorts received 3600 minutes (60 hours) of facilitated group exercise over the 4 weeks. This total equals 900 minutes (15 hours) per week or 180 minutes (3 hours) per day. The BOUNCE exercise program was standardized and included approximately a 5-minute warm-up, 20–50 minutes of light- to vigorous-intensity physical activity, and a 5-minute cool-down. In addition to engaging in various physical activities, participants received handouts on the exercise benefits, components of a healthy lifestyle, and strategies to overcoming barriers to being physically active.
Table 2Four-week BOUNCE summer exercise sessions
Category
Cohort 1, 2009
Cohort 2, 2010
Total exposure
Flexibility
Ballet
0
120
120
Budokon
120
0
120
Pilates
180
120
300
Yoga
240
330
570
Sports skills
Kickball
60
60
120
Basketball
300
300
600
Soccer
300
300
600
Self-defense
240
240
480
Track and field
0
300
300
Tennis
120
0
120
Volleyball
60
120
180
Games
Survivor
75
75
150
Amazing race
75
75
150
Relays
30
0
30
Traditional Fitness
Step aerobics
180
240
420
Spinning
420
420
840
Boot camp
60
60
120
Circuit training
240
240
480
Core training
0
0
0
Latin aerobics
120
0
120
Kickboxing
240
240
480
Dancing
Rumba Zumba
180
180
360
Hip-hop
180
180
360
Cheerleading
180
0
180
Modern dance
0
0
0
All activities total
3600
3600
7200
Note: Values are minutes.
BOUNCE, Behavior Opportunities Uniting Nutrition Counseling and Exercise
During the BOUNCE summer intervention, mothers participated in 2-hour weekly sessions where they received nutrition education, exercise training, and parenting strategies on how to support their daughters' healthy lifestyle program at home. A dietitian, an exercise physiologist, and a developmental psychologist led maternal sessions in English or Spanish. A detailed description of the BOUNCE intervention theoretic foundation has been previously published.
served as the foundation for the intervention design and included the interplay of personal, behavioral, and social and environmental factors. The personal factors included (1) skills-based sessions to develop ability to perform the behavior when desired (e.g., learning a new motor skill or yoga pose); (2) self-efficacy to perform a specific behavior; (3) expectations of positive outcomes (e.g., having more energy and enjoyment after exercise); and (4) attitudes toward exercise and eating. The behavioral factors included (1) self-control by setting behavioral goals; (2) monitoring one's own behavior; and (3) rewarding one's self when goals are achieved. The social and environmental factors consisted of (1) positive role modeling that provides a supportive environment at home and (2) identification of environmental barriers to exercise.
Follow-up sessions
After the 4-week BOUNCE summer program, the Mother–daughter dyads participated in 12 weekly ReBOUNCE afterschool aerobic intervention sessions in the fall (Figure 1). The weekly sessions were 1.5 hours in duration and included physical activity and supplemental information as requested by mothers. The physical activity component was 60 minutes in duration and consisted of a 5-minute warm-up, a 50-minute fitness class, and a 5-minute cool-down. The supplemental information included 30 minutes of nutrition education or parenting training, or sometimes both depending on the topic. Follow-up topics are described in Table 3.
Table 3Weekly ReBOUNCE follow-up sessions
Week
Exercise
Counseling
Nutrition
1
Step aerobics
Welcome Back Review Progress
2
Salsa dancing
Goal Setting: Exercise
Goal Setting: Nutrition
3
Boot camp
Savvy Grocery Shopping
4
Dodgeball or kickball
Raising Children Within Two Cultures
Food Demo with BOUNCE Chef
5
Spinning/walking
Shall We Dance: Communication Part I
6
Swimming
Shall We Dance: Communication Part II
7
Step aerobics
Dealing with Halloween Food Demo with BOUNCE Chef
8
Salsa dancing
Parenting Strategies to Promote Healthy Eating and Exercise
9
Triathlon
Triathlon
Triathlon
10
Dodgeball or kickball
Parenting Strategies to Raise Confident Children
Food Demo with BOUNCE Chef Holidays Tips
11
Spinning/walking
Healthy Plan
12
Swimming
BOUNCE Party
BOUNCE Party
BOUNCE, Behavior Opportunities Uniting Nutrition Counseling and Exercise; ReBOUNCE, 12 weekly follow-up sessions to BOUNCE
Instructors certified by the nationally recognized Cooper Institute led the BOUNCE and ReBOUNCE exercise sessions, which were held at a gymnasium and dance studio located on a university campus and at a community park. Incentives were provided at each BOUNCE and ReBOUNCE session for participants who achieved their weekly goals. These incentives consisted of small low-cost items such as pencils, pens, journals, stickers, and bracelets. At the end of the summer and follow-up sessions, $20 gift cards and exercise equipment (e.g., soccer balls and basketballs, jump-ropes, and yoga mats) were provided to the top three participants who met their goals.
Measures
Data were collected in two cohorts during 2009 and 2010 and four measurement time periods (M1–M4; Figure 1).
Demographic survey
Mother and daughter participants answered a short survey consisting of questions about age, educational status, date and place of birth, and self-described ethnicity.
Attendance
Daily attendance for each participant was used to calculate the average percentage attendance based on the number of days participants attended per week divided by the number of days that the BOUNCE interventions were offered and multiplied by 100. Participants who came late or left early were recorded as having attended that day. In addition, girls were asked about their participation in other structured summer programs aside from BOUNCE.
Adiposity indicators
Percent body fat (%BF) was obtained from a foot-to-foot bioelectric impedance assessment using a Tanita TBF 310 series scale. Measurements of %BF were conducted at the time of the participants' morning arrival during the testing days. A research assistant asked each participant to place her bare feet on the silver foot pads and to stand still while the scale determined the %BF.
The research assistant first entered participant's height, age, gender, and body type (athletic/non-athletic) into the remote display. The Tanita's definition of an “athletic” person was used: one who is involved in intense physical activity of approximately 10 hours per week. Tanita's athletic definition does not include “enthusiastic beginners” who are making a real commitment to exercising at least 10 hours per week, but whose bodies have not yet changed to require the athletic mode. Thus, “athletic” classification was determined by asking participants if they engage in physical activity of approximately 10 hours per week, or by visually determining if they have an athletic body type. All the BOUNCE participants were classified as non-athletic.
The Tanita TBF-310 has been found to be a convenient method to assess %BF in groups of children. Children's %BF generated by this scale has been associated with anthropometric measurements (e.g., sum of skinfolds and waist circumference), with intraclass correlation coefficients between 0.90 and 0.95.
have suggested using the Tanita TBF-310 to obtain group mean values rather individual values in children. The Tanita TBF-310 has also been validated in women against dual energy radiograph absorptiometry with a correlation coefficient of 0.94.
Abdominal fat was assessed through waist circumference measurements following guidelines by National Health and Nutrition Examination Survey procedures.
For this measurement, a spring-gauge, non-elastic flexible measuring tape was placed at a point midway between the participant's lowest rib to the top of the iliac crest at the end of a normal expiration. A research assistant made sure that the tape was comfortable without compressing clothing and was parallel to the floor. Measurements were taken twice, to the nearest 0.5 cm, and the average of the two measurements was recorded as the final value.
Body weight and height were measured to the nearest 0.1 kg and 0.1 cm, respectively, using a scale (Tanita TBF 310) and a stadiometer (Seca 213). Each participant was told to remove her shoes and socks or any heavy garments before stepping onto the scale. Barefoot height was measured with participants' heels together and toes pointed slightly outward at ∼60 degrees. While participants' arms were at their sides, their shoulders level, and their heels, buttocks, and back of the head touching the vertical backboard, the headpiece was lowered until it firmly touched the crown of the head.
BMI was calculated by using standard formula, and values were then used to identify the age- and gender-specific percentile for each child using CDC growth charts.
Based on these percentiles, each child was classified as overweight (85th–94th percentile) or obese (≥95th percentile). Using the WHO obesity classification,
mothers with a BMI ≤24.9 were considered to be normal weight; overweight with a BMI ≥25.0≤29.9; and obese with a BMI ≥30.
Data Analysis
Descriptive statistics including means and SDs were calculated to identify basic characteristics of the data and sample population. Variables were assessed for normality by evaluating skewness and kurtosis. Data were combined across the two cohorts who participated in the 4-week BOUNCE intervention and the 12-week ReBOUNCE follow-up sessions. To detect if the interventions reduced adiposity indicators in Latina girls, changes in %BF, waist circumference, and BMI at M1 (baseline) and post-interventions (M2–M4) were analyzed using paired-sample t-tests. Alpha was set at 0.05. A repeated-measures ANCOVA was used to address the second research question about whether maternal %BF, waist circumference, and BMI (covariates) at M2 have an impact on the daughters' adiposity measures at M2, M3, and M4. All analyses were conducted using SPSS, version 20.0.
Results
Baseline Demographic Characteristics of Study Sample
At baseline (M1), the sample consisted of 61 mother–daughter pairs. Daughters were predominately born in the U.S., whereas a majority of their mothers were from Mexico (Table 4). More than half of the mothers had a high school education. The majority of the mothers reported an annual family income of ≤$30,000. Mothers and daughters had high baseline levels of %BF and abdominal fat, and most of them were classified as obese.
Table 4Baseline characteristics of study sample (N=61)
Daughters' participation during the 4 weeks of the BOUNCE summer intervention was on average 90% (SD±16%). Conversely, daughters attended the ReBOUNCE sessions less frequently with an average participation of 24% (SD±30%). Reasons for missing ReBOUNCE sessions included competing demands (e.g., tutoring siblings, religious education, school activities); conflicting parent work schedules; and transportation problems. Aside from BOUNCE, the majority of the girls (92%) reported that they did not participate in any other type of program during the summer. Those who reported being involved in an additional summer program participated in YMCA or sport programs sponsored by their church.
Impact of Interventions on Daughters' Adiposity Indicators
The change in combined cohorts from M1 to M4 for %BF was a 2.87% point decrease; for waist circumference, a 9.10 cm decrease; and for BMI, a 2.30 decrease (Table 5). Paired-sample t-tests were conducted to evaluate the impact of intervention on lowering %BF, waist circumference, and BMI in Latina girls. Results of the paired-sample t-tests showed decreases in %BF from M1 to M2 (p<0.001) and from M1 to M3 (p=0.019). Also, there were reductions in waist circumference from M1 to M2 (p=0.026), and in BMI from M1 to M2 (p<0.001; Table 6).
Table 5Mean and SD of daughters' adiposity indicators at M1–M4
A repeated-measures ANCOVA was utilized to address research question (2) and to examine differential change in the daughters' %BF, waist circumference, and BMI over time after controlling for the maternal adiposity at M2. The results indicated that there were no differences in these three measures for the daughters after controlling for maternal %BF, waist circumference, and BMI.
Discussion
The primary finding of this exploratory study revealed reductions in %BF, waist circumference, and BMI after participation in the summer BOUNCE intervention. In terms of %BF, the findings are consistent with previous research (using a longer intervention and more-complex research design with inclusion of a control group) that indicated an approximately 2.5%–3.0% reduction in body fat as a result of physical activity intervention compared with 0.6% body fat change in the control group.
Preliminary findings of the effect of a 3-year after-school physical activity intervention on fitness and body fat: the Medical College of Georgia Fitkid Project.
Results from the present study also showed that the BOUNCE summer intervention lowered waist circumference. This is particularly encouraging because recent studies have reported that this measure is a better determinant of cardiovascular disease than BMI.
In addition, reduction was observed from M1 to M2 in daughters' BMI (0.381). Although this reduction is modest, it is congruent with the published expert committee recommendations for obesity treatment, which suggest a gradual weight loss of 1 pound per month for overweight children aged 6–11 years.
Expert Committee Expert committee recommendations regarding the prevention, assessment, and treatment of child and adolescent overweight and obesity: summary report.
Preliminary findings of the effect of a 3-year after-school physical activity intervention on fitness and body fat: the Medical College of Georgia Fitkid Project.
body fatness may be a better measure to assess efficacy of physical activity interventions because physical activity can increase lean mass, which in turn may increase BMI. The current data show that the variable %BF changed from M1 to M2 (p<0.001); M1 to M3 (p=0.019); and M1 to M4 (p=0.072). However, BMI changed only from M1 to M2 (p<0.001), not in the other comparisons.
All three measures showed nonsignificant declines during the ReBOUNCE follow-up sessions. Low retention rate for the ReBOUNCE sessions influenced the internal reliability of these results. Although participation during the ReBOUNCE was low, participation during the day-long BOUNCE summer was high. It is possible that limited opportunities for the girls to participate in summer programs aside from BOUNCE may make them and their parents more willing to participate in this kind of interventions. Further, the high attendance rate of BOUNCE participants during the summer is consistent with that reported by Baranowski et al.
who found a 95.5% attendance rate in a sample of African-American girls who participated in a summer intervention. Thus, these finding suggest that future research target summer season as an optimal period for intervention.
Of particular interest is identification of strategies that may be offered to promote sustained participation during ReBOUNCE follow-up sessions amid access barriers (e.g., competing family demands, conflicting parental schedules, and transportation issues). Some of these strategies may include providing transportation and establishing partnerships with fitness programs in the area to maintain focus and support for an active lifestyle. Future studies should employ larger sample sizes and an RCT design, which would strengthen the scientific design of replicating efforts.
The secondary findings indicated that mothers' %BF, waist circumference, and BMI did not have an impact on the same measures for their daughters as a result of the present intervention. This finding was not totally unexpected given the greater participation of the daughters compared to mothers. Further, the focus of the maternal intervention was to provide them with knowledge and skills to support their daughter's healthy habits. The daughters still made gains in adiposity measures independent of their mothers' status.
The evidence about the health risks of fatness and obesity continues to mount. More research is needed to identify what other factors, including environmental and sociocultural ones, might contribute to the effects of the BOUNCE interventions and the risk of obesity among Latina girls. For example, understanding the mental and emotional aspects of obesity may be as important as documenting physiologic effects. Future studies should include ecologic approaches to better assess these complex phenomena.
Conclusion
In addressing the quandary of childhood obesity among Latino girls, this exploratory study provides an innovative approach to address childhood obesity in an underserved population at a critical period of time. Although the proposed research design reflects a “real-world” approach, it also limited the external generalizability of the results. Therefore, the current conclusions should be viewed cautiously. Future studies should expand on this line of research and refine design weaknesses.
The current findings indicate that an intensive summer intervention known as BOUNCE may be effective in reducing adiposity indicators in Latina girls, but sustained effects could not be demonstrated at additional follow-up measurement periods, because of high attrition. More research needs to be conducted regarding physical activity maintenance and innovations within the population. Mothers' adiposity did not have an effect on their daughters' %BF, abdominal fat, or BMI.
This was the first study of its kind designed to examine adiposity indicators among Latina girls and their mothers. The intense intervention and booster sessions were designed to improve adiposity indicators specifically among minority children. Mothers were included as a unique support component, but the authors had hoped to find residual effects on their adiposity measures. However, the value of booster sessions after the summer, as well as mother–daughter dyads remains unclear.
Research design issues such as participant mortality and a Type III error (incorrectly assuming an intervention was delivered to participants) may have compromised findings related to booster effectiveness and mothers' adiposity measures.
In contrast to the current findings, however, it seems intuitive to continue to argue that follow-up sessions and the inclusion of mothers are important components of overall ecologic strategies to improve Latina girls' adiposity measures. Overall, results from this study address a gap in knowledge regarding the impact of interventions and follow-up sessions for reducing relevant body fatness in Latina girls who are at increased risk for obesity.
Publication of this article was supported by the Robert Wood Johnson Foundation.
This study was funded by the Robert Wood Johnson Foundation through its national program, Salud America! The RWJF Research Network to Prevent Obesity Among Latino Children (www.salud-america.org). Salud America!, led by the Institute for Health Promotion Research at The University of Texas Health Science Center at San Antonio, Texas, unites Latino researchers and advocates seeking environmental and policy solutions to the epidemic.
The authors thank the families who participated in this study. The authors' deepest appreciation is intended to all interns, volunteers, instructors, and coordinators who spent countless hours in the preparation, implementation, and data collection of this study. This work also was supported by the St. Luke's Episcopal Health Charities Foundation and Neighborhood Centers, Inc.
No financial disclosures were reported by the authors of this paper.
References
Ogden C.L.
Carroll M.D.
Curtin L.R.
Lamb M.M.
Flegal K.M.
Prevalence of high body mass index in U.S. children and adolescents, 2007–2008.
Preliminary findings of the effect of a 3-year after-school physical activity intervention on fitness and body fat: the Medical College of Georgia Fitkid Project.
Asthma and maternal body mass index are related to pediatric body mass index and obesity: results from the Third National Health and Nutrition Examination Survey.
Rodriguez AX, Olvera N, Leung P, et al. Association between the summer season and body fatness and aerobic fitness among Hispanic children. J Sch Health. Accepted.
00883-5&id=gr1.jpg){kind=link}