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Citation:

 Black, Maureen M., et al  Overweight Adolsescent African-American Mothers Gain Weight in Spite of Intentions top Lose Weight JADA 106:1: 80-87 2006


PubMed ID: 16390669
Study Design:
Prospective cohort study and cross-sectional study
Class:
B - Click here for explanation of classification scheme.
POSITIVE: See Research Design and Implementation Criteria Checklist below.
Research Purpose:

To determine how dietary patterns, self esteem, depressive symptoms, and intention to lose weight were associated with body size among African American Adolescent mothers 1 year after delivery and with changes in body size over the next year.

Inclusion Criteria:
  • African-American Mothers
  • Participants in a longitudinal randomized controlled trial of a home intervention program to promote parenting and adolescent development among low income families.
  • < 18 years of age
  • Family income <185% of poverty level
  • Intention of being primary caregiver
  • in guardianship of an adult
  • Mothers with infants who were full-term (> 37 weeks) and birth weight >2,500 g
Exclusion Criteria:
  • Adolescent African-American mothers not meeting inclusion criteria.
  • Mothers with infants with congenital problems, chronic illness or disabilities.
Description of Study Protocol:

Recruitment : Recruited participants of home intervention trial from 3 urban hospitals, shortly after delivery. Study was explained and eligible, interested mothers were given an appointment to obtain baseline data, further determine eligibility, and obtain consent.

 

Design: Cross sectional study and trend analysis

 

Blinding used (if applicable): N/A

 

Intervention (if applicable): N/A

 

Statistical Analysis:

  • Covariates in all analyses:  intervention status, maternal age at delivery, education and breastfeeding history
    • caloric intake included both in and out of models: no differences so results presented without adjusting for energy intake

Cross sectional data:

  • multivariate analysis of covariance model  for dietary patterns, intention to lose weight, self esteem, depressive symptoms by BMI group.

Longitudinal data:

  • multiple linear regression model to examine changes in BMI z score from 1-2 years after delivery were related to dietary patterns, self-esteem, depressive symptoms, or intention to lose weight reported at 1 year.

 

Data Collection Summary:

Timing of Measurements: Baseline 3 weeks after delivery. 1 year post delivery and 2 years post delivery.

Dependent Variables: 

  • Change in body mass index (BMI) (kg/m2) z score = BMI z score at Year 1 - BMI z score at Year 2
    • BMI calculated from weight and height measured using standard procedures

Independent Variables

  • Dietary Patterns: Youth Adolsescent Food Frequency Questionaire
  • Depressive symptoms: Beck Depression Inventory
  • Self Esteem:  Rosenberg Self Esteem Scale

Control Variables:

  • BMI at year 1
  • Intention to lose weight:  "I am purposively trying to lose weight by eating less" (yes/no)
  • breastfeeding history
  • intervention status
  • age at delivery
  • educaton

 

Description of Actual Data Sample:

 

Initial N: 219 eligible. 181 agreed to participate; 127 with complete data (70%)

Attrition (final N): N=118 at year 1 (baseine); N=98 at year 2

Age:  13.5-17.9 years ( 16.3 + 1 mean/SD)

Ethnicity:: African American

Other relevant demographics: 66% in high school, 68% unemployrd, 92% single (51% in a relationship)

Anthropometrics :

  • Under/Normal weight: 51 (43%)
  • At risk for overweight: 28 (24%)
  • overweight: 39 (33%)

Location: United States

 

Summary of Results:

 

Key Findings

  • One year after delivery, 33.0% of mothers were overweight (BMI> 95th percentile) and 23.7% were at risk for overweight (BMI > 85th percentile and < 95th percentile).
  • Mothers consumed a daily average of 2,527 kcal and 4.1 high-fat snacks.
  • A total of 11% of normal-weight mothers, 22% of mothers at-risk for overweight, and 44% of overweight mothers reported intention to lose weight (chi-square=10.8, P<0.01).  However in multivariate analysis, there were no differences in any of the variables (dietary patterns, self-esteem, or depressive symptoms) by the mothers' intentions to lose weight.
  • Average maternal BMI z score increased 0.13 (3.9 kg, 95% CI: 2.4, 5.4, P<0.01) between 1 and 2 years after delivery.
  • Dietary patterns, self-esteem, depressive symptoms, and intention to lose weight were not realted to body size or increase in body size.

Variables

Under/Normal weight

at risk for overweight

overweight

 
Dietary patterns (servings in 6 categories, Kcal/kg/d)

Mean, SD

2587, 1184 kcal/kg/d

Mean, SD

2405, 1253 kcal/kg/d

Mean, SD.

2549, 1083 kcal/kg/d

no significant difference

Self esteem

 32.7, 5.1

 33.9, 4.6

 32.7, 4.3

no significant difference

Depressive symptoms

7.8, 11.1 

 7.4, 8.3

 6.1, 8.8

no significant difference
Intent to lose weight (%yes) 10.9 22.2 43.8 p=0.01

 

Other Findings:

average change in BMI z score was 0.13+0.53. Most mothers, hoever remained in the same BMI cateory (76%).  Approximately 16% moved upa category and 8% moved down a category.

 

Author Conclusion:

Authors conclude  that "Programs that emphasize weight loss or thinness may have limited usefullness among African American adolescents, who may not conceptualize overweight in negative terms". They further suggest that attention should be focused on multilevel public health interventions, including alternatives to high fat snacks. In the abstract, authors conclusions include: overweight was a common problem in adolescent African American mothers and increased over time, and may benefit from strategies to identify alternatives to high fat snack food.

Reviewer Comments:

 Limitations include self reporting, accuracy of food frequency records to assess intake, physical activity not considred, and high attrition rate. Additional concerns include that although eligibility required participants living with an adult guardian, not all subjects complied, and there was no information on which of the subjects were in the intervention group (was there an equal distribution)


Research Design and Implementation Criteria Checklist: Primary Research
Relevance Questions
  1. Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies)
Yes
  2. Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about?
Yes
  3. Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to nutrition or dietetics practice?
Yes
  4. Is the intervention or procedure feasible? (NA for some epidemiological studies)
N/A
 
Validity Questions
1. Was the research question clearly stated?
Yes
  1.1. Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified?
Yes
  1.2. Was (were) the outcome(s) [dependent variable(s)] clearly indicated?
Yes
  1.3. Were the target population and setting specified?
Yes
2. Was the selection of study subjects/patients free from bias?
Yes
  2.1. Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study?
Yes
  2.2. Were criteria applied equally to all study groups?
Yes
  2.3. Were health, demographics, and other characteristics of subjects described?
Yes
  2.4. Were the subjects/patients a representative sample of the relevant population?
No
3. Were study groups comparable?
Yes
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT)
Yes
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline?
Yes
  3.3. Were concurrent controls used? (Concurrent preferred over historical controls.)
N/A
  3.4. If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis?
Yes
  3.5. If case control or cross-sectional study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable. Criterion may not be applicable in some cross-sectional studies.)
Yes
  3.6. If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")?
N/A
4. Was method of handling withdrawals described?
Yes
  4.1. Were follow-up methods described and the same for all groups?
Yes
  4.2. Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.)
Yes
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for?
Yes
  4.4. Were reasons for withdrawals similar across groups?
???
  4.5. If diagnostic test, was decision to perform reference test not dependent on results of test under study?
N/A
5. Was blinding used to prevent introduction of bias?
Yes
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate?
N/A
  5.2. Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.)
N/A
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded?
Yes
  5.4. In case control study, was case definition explicit and case ascertainment not influenced by exposure status?
N/A
  5.5. In diagnostic study, were test results blinded to patient history and other test results?
N/A
6. Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described?
Yes
  6.1. In RCT or other intervention trial, were protocols described for all regimens studied?
N/A
  6.2. In observational study, were interventions, study settings, and clinicians/provider described?
Yes
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect?
Yes
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured?
N/A
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described?
N/A
  6.6. Were extra or unplanned treatments described?
N/A
  6.7. Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups?
N/A
  6.8. In diagnostic study, were details of test administration and replication sufficient?
N/A
7. Were outcomes clearly defined and the measurements valid and reliable?
Yes
  7.1. Were primary and secondary endpoints described and relevant to the question?
Yes
  7.2. Were nutrition measures appropriate to question and outcomes of concern?
Yes
  7.3. Was the period of follow-up long enough for important outcome(s) to occur?
Yes
  7.4. Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures?
Yes
  7.5. Was the measurement of effect at an appropriate level of precision?
N/A
  7.6. Were other factors accounted for (measured) that could affect outcomes?
No
  7.7. Were the measurements conducted consistently across groups?
Yes
8. Was the statistical analysis appropriate for the study design and type of outcome indicators?
Yes
  8.1. Were statistical analyses adequately described and the results reported appropriately?
Yes
  8.2. Were correct statistical tests used and assumptions of test not violated?
Yes
  8.3. Were statistics reported with levels of significance and/or confidence intervals?
Yes
  8.4. Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)?
N/A
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)?
N/A
  8.6. Was clinical significance as well as statistical significance reported?
No
  8.7. If negative findings, was a power calculation reported to address type 2 error?
No
9. Are conclusions supported by results with biases and limitations taken into consideration?
Yes
  9.1. Is there a discussion of findings?
Yes
  9.2. Are biases and study limitations identified and discussed?
Yes
10. Is bias due to study’s funding or sponsorship unlikely?
Yes
  10.1. Were sources of funding and investigators’ affiliations described?
Yes
  10.2. Was the study free from apparent conflict of interest?
Yes
 
 

Copyright American Dietetic Association (ADA).