ORP: Nutrition Prescription for Gestational Weight Gain (2014)

Citation:

 Guelinckx I, Devlieger R, Mullie P, Vansant G. Effect of lifestyle intervention on dietary habits, physical activity, and gestational weight gain in obese pregnant women: A randomized controlled trial. Am J Clin Nutr. 2010; 91: 373–380.

PubMed ID: 1995539
 
Study Design:
Randomized Controlled Trial
Class:
A - Click here for explanation of classification scheme.
Quality Rating:
Positive POSITIVE: See Quality Criteria Checklist below.
Research Purpose:

To determine whether a lifestyle intervention based on a brochure or on an active education can improve dietary habits, increase physical activity (PA) and reduce gestational weight gain (GWG) in obese pregnant women.

Inclusion Criteria:
  • Obese (BMI higher than 29.0 according to IOM criteria)
  • Caucasian
  • Consecutively attended the prenatal clinic before 15 weeks gestation
  • Provided informed consent
  • Free of pre-existing or gestational diabetes
  • Singleton pregnancy
  • Free of premature labor (delivery before 37 weeks gestation)
  • Free of need for nutritional advice due to a metabolic disorder, kidney problems, Crohn's disease and allergic conditions
  • Had adequate knowledge of the Dutch language.
Exclusion Criteria:
  • Not obese (BMI less than 29.0 according to IOM criteria)
  • Non-white
  • Recruited after 15 weeks gestation
  • Pre-existing or gestational diabetes
  • Multiple pregnancy
  • Premature labor (delivery before 37 weeks gestation)
  • Need for nutritional advice due to a metabolic disorder, kidney problems, Crohn's disease and allergic conditions
  • Had inadequate knowledge of the Dutch language.
Description of Study Protocol:

Recruitment

 Subjects were recruited from the antenatal clinic.

Design

In this randomized control trial, subjects were randomly assigned to one of three groups. The control group received routine prenatal care, the second group (passive group) was given a brochure during the first prenatal consultation, and the third group (active group) received both the brochure and counseling from a trained nutritionist during three group sessions. Energy intake was not restricted in any group. Subjects were asked to record a seven-day food diary during each trimester of pregnancy to obtain nutritional data and to calculate daily intake of fruits and vegetables. Subjects were weighed at each antenatal visit and each subject followed the standard clinical protocol for pregnant women. A physical activity (PA) score was also calculated for each trimester of pregnancy by using the Baeke questionnaire.

Intervention

Both the passive and active groups were given a brochure during the first prenatal consultation, which provided advice on nutrition and on PA and tips to limit pregnancy-related weight gain. The active group also was actively counseled by a trained nutritionist in three one-hour group sessions. A maximum of five women were brought together in these sessions, which were scheduled at 15, 20 and 32 weeks of pregnancy. The sessions provided subjects with recommendations on a balanced, healthy diet (9% to 11% of energy from protein, 30% to 35% from fat and 50% to 55% from carbohydrates). The dietary intervention aimed at limiting the intake of energy-dense foods by substituting them with healthier alternatives, increasing low-fat dairy products, increasing whole grains and reducing saturated fats. More general topics such as energy balance, body composition, nutrition facts labels and how to increase PA were discussed. Techniques of behavioral modification were used to give the women insight into controlling periods of emotional eating and preventing binge eating sessions.

Statistical Analysis

  • Continuous variables were analyzed by using ANOVA followed by post hoc tests, if normal distribution and equal variances were assumed
  • Continuous variables of patient characteristics were tested with a Kruskal-Wallis test
  • Categorical variables were analyzed using Kendall's tau-B test
  • Dietary outcomes and PA scores were analyzed using a repeated-measures ANOVA with intervention group and trimester as between- and within-subject variables, respectively. Interaction between both factors was included to verify whether evolution over time differed between groups.
Data Collection Summary:

Timing of Measurements

 Weight was measured at each antenatal visit while subjects wore indoor clothing but no shoes. Baseline weight was self-reported pre-pregnancy weight. Final weight measurements were performed at the delivery room on delivery day. Height of subjects was measured once at the first visit. Age, parity, smoking behavior and use of pregnancy dietary supplements were recorded at inclusion. Subjects were asked to record a seven-day food diary during each trimester of pregnancy with as much detail as possible, including weight measures or household units and specific recipes or food brand names; the nutritionist checked each record together with the subject for completeness.

Dependent Variables

  • Gestational weight gain
  • Physical activity (scored by using the Baeke questionnaire)
  • Dietary habits (evaluated by analyzing seven-day food diary).

Independent Variables

  • Brochure only
  • Brochure plus lifestyle education from nutritionist during group sessions.

Control Variables

 One group received routine prenatal care with no additional lifestyle education or information.
Description of Actual Data Sample:
  • Initial N: 195 pregnant women
  • Attrition (final N): 122 pregnant women
  • Age: 29.4±4.4 years (control group), 28.7±4.0 years (passive group) and 28.0±3.6 years (active group) (P=0.384)
  • Ethnicity: White
  • Other relevant demographics: Subjects were fairly matched on gestational age at recruitment (P=0.228), nulliparae (P=0.453), smoking (P=0.184) and vitamin use (P=0.639)
  • Anthropometrics: Subjects were fairly matched on pre-pregnancy weight (P=0.476), height (P=0.199) and pre-pregnancy BMI (P=0.849)
  • Location: University Hospital of Leuven, Belgium.
Summary of Results:

Key Findings

  • Mean energy intake did not change throughout pregnancy for all groups, shown by lack of significant interaction between trimester and group (P=0.065)
  • There was a significantly lower energy intake in the passive (P=0.016) and active (P=0.004) groups than in the control group
  • PA scores were comparable in all groups (P=0.478)
  • GWG was not significantly different between the active (9.8kg±7.6kg) or passive (10.9kg±5.6kg) group and the control group (10.6kg±6.9kg) (P=0.749)
  • The percentage of subjects with GWG greater than 11.2kg was comparable in the control group (48.4%), the passive group (45.9%) and the active group (40.5%) (P=0.847)
  • GWG was significantly correlated with birth weight (R=0.247, P=0.001) and negatively correlated with pre-pregnancy BMI (R=-0.369, P=0.001), multi-parity (R=-0.163, P=0.034) and smoking (R=-0.237, P=0.002)
  • A significant effect on birth weight was not detected; mean birth weight and the number of children with high birth weight (greater than 4,000g) in the three groups were comparable
  • No significant differences in pregnancy or delivery complications were seen between the groups.
Author Conclusion:

Both lifestyle interventions improved the nutritional habits of obese women during pregnancy. Neither PA nor GWG was affected. To obtain a significant decrease in GWG, an individually designed caloric intake restriction based on energy expenditure data should be included.

Funding Source:
University/Hospital: DANONE Institute Belgium and University Hospital Leuven
Reviewer Comments:
Quality 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 dieteticspractice? Yes
  4. Is the intervention or procedure feasible? (NA for some epidemiological studies) Yes
 
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? Yes
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 or comparisons used? (Concurrent preferred over historical control or comparison groups.) Yes
  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? N/A
  3.5. If case control 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.) N/A
  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? Yes
  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? No
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? No
  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.) No
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? N/A
  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? Yes
  6.2. In observational study, were interventions, study settings, and clinicians/provider described? N/A
  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? Yes
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? Yes
  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? Yes
  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? Yes
  7.6. Were other factors accounted for (measured) that could affect outcomes? Yes
  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)? Yes
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? Yes
  8.6. Was clinical significance as well as statistical significance reported? Yes
  8.7. If negative findings, was a power calculation reported to address type 2 error? Yes
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