AWM: Eating Frequency and Patterns (2013)

Citation:
 
Study Design:
Class:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:
  • To determine whether the addition of a structured post-dinner snack would increase weight loss among obese night snackers participating in a partial meal replacement program
  • To examine the impact of a partial meal replacement program on weight loss in obese night snackers.
Inclusion Criteria:
  • Adults ages 18 to 65 years
  • BMI 30 or higher
  • Stable weight history for six months (less tha 15-pound weight fluctuation)
  • Report that night snacking contributed to their obesity 
    • Response of four or five on the night snacking question, 'To what extent does night snacking contribute to your weight problem?' (value of four represents 'quite a bit' and a value of five represents 'to a very large extent')
  • Adequate health status based on physical exam by physician including height, body weight, waist and blood pressure
  • Informed consent consistent with HIPPA guidelines was obtained.
Exclusion Criteria:
  • Less than 18 years of age or more than 65 years of age
  • BMI less than 30
  • Unstable weight history the previous six months (more than 15-pound weight fluctuation)
  • Report that night snacking did not overly contribute to their obesity: 
    • Response of one to three on the night-snacking question, 'To what extent does night snacking contribute to your weight problem?'  (value of one corresponded to 'not at all' and a value of five corresponded to 'extremely')
  • Pre-existing medical conditions, including cardiovascular disease, poorly controlled diabetes, hypertension, pregnancy, lactation or renal disease.
Description of Study Protocol:

Recruitment

  • Newspaper advertisements
  • Flyers posted in local hospitals and physician office waiting rooms 
  • Pre-screened for initial eligibility over the telephone (anthropometric data, weight history and night snacking question responses were obtained).

Design

Randomized controlled trial.

Intervention

  • Participants were randomized into either the 'post-dinner snack' (PDS) group or the 'no snack' (NS) group
  • Registered dietitians provided instruction on the use of the Kashi® GOLEAN® partial meal replacement program which included:
    • Standardized bowl of ready-to-eat cereal for breakfast
    • Bar at mid-morning
    • Ready to drink shake for lunch
    • Supper was individually planned with registered dietitian
  • Participants in the post-dinner snack group were also instructed to eat a standardized bowl of ready-to-eat cereal and 2/3 cup of low-fat milk 90 minutes after completion of supper
  • Food supplies were provided to all participants
  • The program was followed for eight weeks
  • Follow-up visits were conducted at two,four, six and eight weeks
  • At the four- and eight-week follow-up visits, questionnaires were completed, anthropometric measurements were measured and blood work was obtained. Participants also met with the physician to monitor health status and the dietitian to monitor diet appropriateness.

 

Product Name Serving Size Energy (kJ) Protein (g) Fat (g) Fiber (g)
GOLEAN® cereal 177.44ml 502.42 8 1 10
GOLEAN®  bar 1 bar 1214.17 13 6 6
GOLEAN® shake 325ml 962.96 15 3 7

Statistical Analysis

  • SPSS 11.5
  • Data for participants who completed the study were analyzed using paired-sample and independent-sample T-tests
  • Simes correction (sequentially rejective modification of the Bonferroni correction for multiple comparisons) was applied to maintain a 0.05 alpha level for each set.

 

Data Collection Summary:

Timing of Measurements

  • Anthropometrics were measured at baseline, week four and week eight
    • Height
    • Body weight
    • Waist circumference
    • Body fat content 
  • Blood work was obtained at baseline, week four and week eight
  • Night snacking question was administered by registered dietitians and completed at baseline, week four and week eight
  • Night Eating Syndrome Questionnaire was administered by registered dietitians and completed at baseline, week four and week eight
  • Center for the Epidemiological Study of Depression scale, a measure of dysphoric mood, was administered by registered dietitians and completed at baseline, week four and week eight
  • Compliance was measured at weeks two four, six and eight. 

Dependent Variables

  • Body weight
  • BMI
  • Body fat content measured by a BODPOD analyzer using air displacement plethysmography
  • Waist measurement
  • Triglycerides
  • Total cholesterol
  • HDL-cholesterol
  • LDL-cholesterol.

Independent Variables

  • Instruction by registered dietitians on the use of the Kashi® GOLEAN® partial meal replacement program
  • Instruction by registered dietitians on the standardized evening snack to the PDS group
  • Food supplies were provided to each participant.

 Control Variables

  • Night-snacking question
  • Night Eating Syndrome Questionnaire
  • Center for the Epidemiological Study of Depression scale, a measure of dysphoric mood
  • Energy intake. 
Description of Actual Data Sample:
  • Initial N: 80 participants
    • PDS group: 40 (nine men, 31 women)
    • NS group: 40 (10 men, 30 women)
  • Attrition (final N): 61 participants
    • 29 in PDS group (eight men, 21 women) and 32 in NS group (nine men, 23 women)
    • 19 participants dropped out due to personal illness (unrelated to the study), family-related illness/deaths, incompatible schedules or loss of interest
  • Age:
    • PDS group: 44.76±11.67
    • NS group: 47.53±10.35
  • Other relevant demographics:
    • Daily energy intake (kJ):
      • PDS group: 9,702.38±3,835.5
      • NS group: 9,983±4,181.45
    • Night snacking question: 
      • PDS group: 3.97±0.91
      • NS group 4.09±0.86
    • Night-eating syndrome questionnaire:
      • PDS group: 17.28±7.81
      • NS group: 19.78±7.82
    • Center for the Epidemiological Study of Depression scale:
      • PDS group: 12.52±10.49
      • NS group: 10.9±6.9
  • Anthropometrics
    • Body weight (kg):
      • PDS group: 109.97±22.92
      • NS group: 106.91±15.87
    • BMI:
      • PDS group: 38.34±6.84
      • NS group: 37.68±4.63
    • Body fat percentage:
      • PDS group: 45.98±7.34
      • NS group: 46.12±6.14
    • Waist (cm):
      • PDS group: 111.85±17.35
      • NS group: 114.44±10.69
  • Location: Multi-center trial in the United States.
Summary of Results:

Key Findings

  • Body weight (kg) -4.23 mean change from baseline (P<0.0001)
    • PDS group -3.71 (P<0.0001)
    • NS group -4.71 (P<0.0001)
  • BMI -1.48 mean change from baseline (P<0.0001)
    • PDS group -1.31 (P<0.0001)
    • NS group -1.63 (P<0.0001)
  • Body fat percentage -1.36 mean change from baseline (P<0.0001)
    • PDS group -1.45 (P<0.0001)
    • NS group -1.27 (NS)
  • HDL -0.09 mean change from baseline (P<0.01)
  • Night snacking question -1.31 mean change from baseline (P<0.0001)
  • No statistically significant differences between the PDS and NS groups in Anthropometrics data, laboratory data or questionnaire responses. 

Other Findings

 Change from Baseline to Week Eight

Variable Change Mean SD T-test

Statistical

Significance

Body weight (kg) -4.23 3.6 9.2 P<0.0001
Body mass index -1.48 1.23 9.35 P<0.0001
Body fat %a -1.36 2.23 4.67 P<0.0001
Waist (cm)b -6.4 5.96 7.59 NS
Triglycerides (mmol per L)c 0.13 1.01 0.95 NS
Cholesterol (mmol per L)c -0.27 0.93 2.72 NS
HDL-cholesterol (mmol per L)c -0.09 0.22 2.99 P<0.01
LDL-cholesterol (mmol per L)b -0.21 0.69 2.17 NS
Energy intake (kJ)d -2,155.97 5,083.07 2.72 NS
Night-snacking questione -1.31 1.37 5.72 P<0.0001
NESQ scoref -1.25 7.21 1.15 NS
CESD scoref -1.52 6.96 1.42 NS

aN=59, bN=50, cN=54, dN=41, eN=36, fN=42.

Change from Baseline to Week Eight by Groups

Variable

PDS Group

Change Mean

PDS Group

SD

PDS Group

Statistical Significance

NS Group

Change Mean

NS Group

SD

NS Group

Statistical Significance

T-test

Statistical Significance

Body weight (kg) -3.71 3.29 P<0.0001 -4.71 3.84 P<0.0001 1.09 NS
Body mass index -1.31 1.1 P<0.0001 -1.63 1.34 P<0.0001 1.01 NS
Body fat % -1.45c 1.7 P<0.001 -1.27a 2.64 NS 0.3 NS
Waist (cm) -5.56d 6.01 P<0.0001 -7.3f 5.89 P<0.0001 1.03 NS
Triglycerides (mmol per L) 0.32e 1 NS -0.04b 1 NS 1.3 NS
Cholesterol (mmol per L) -0.05e 0.53 NS -0.46b 0.84 P<0.01 2.07 NS
HDL-cholesterol (mmol per L) -0.05e 0.18 NS -0.13b 0.25 NS 1.25  NS
LDL-cholesterol (mmol per L) -0.11f 0.56 NS -0.29c 0.78 NS 0.95 NS
Energy intake (kJ) -982.91k 4,411.26 NS -3,074.02g 5,471.19 NS 1.32 NS
Night-snacking question -1.25l 1.34 P<0.01 -1.35i 1.42 P<0.001 0.21 NS
NESQ score 0.68j 6.36 NS -2.72e 7.59 NS 1.58 NS
CESD score -0.05i 7.46 NS -2.86h 6.34 NS 1.32 NS

 aN=31, bN=29, cN=28, dN=26, eN=25, fN=24, gN=23, hN=22, iN=19, jN=19, kN=18, lN=16

Change from Baseline to Week Eight for Those Who Had Been Compliant at Least 75% of the Time

Variable

PDS Group

Change Mean

PDS Group

SD

PDS Group

Statistical Significance

NS Group

Change Mean

NS Group

SD

NS Group

Statistical Significance

T-test

Statistical

Significance

Body weight (kg) -4.16 2.78 P<0.0001 -5.05 3.93 P<0.0001 0.92 NS
Body mass index -1.45 0.91 P<0.0001 -1.74 1.38 P<0.0001 0.86 NS
Body fat % -1.81 1.61 P<0.0001 -1.59 2.36 P<0.001 0.39 NS
Waist (cm) -6.03f 6.49 P<0.001 -7.03a 5.99 P<0.0001 0.53 NS
Triglycerides (mmol per L) 0.34f 1.09 NS -0.04b 4.97 NS 1.3 NS
Cholesterol (mmol per L) -0.08f 0.45 NS -0.41 0.8 NS 1.71 NS
HDL-cholesterol (mmol per L) -0.03f 0.1 NS -0.13 0.27 NS 1.6  NS
LDL-cholesterol (mmol per L) -0.15g 1.61 NS -0.24 0.74 NS 0.46 NS
Energy intake (kJ) -1,123.36i 4,712.81 NS -2,911.2d 5,551.48 NS 1 NS
Night-snacking question -1.46j 1.39 P<0.01 -1.47g 1.46 P<0.001 0.02 NS
NESQ score 1.25h 6.28 NS -3.67c 5.84 P<0.01 2.53 NS
CESD score 0.24g 8.04 NS -3.09e 5.48 NS 1.54 NS

aN=30, bN=25, cN=24, dN=23, eN=22, fN=20, gN=19, hN=16, iN=14, jN=13

Author Conclusion:

Adding a structured post-dinner snack resulted in no additional improvements in weight loss, body size, energy intake or chronic disease risk. The partial meal program was effective in reducing body weight, BMI, body fat percentage, waist measurements, cholesterol levels and night snacking behaviors in obese night snackers.

Funding Source:
Industry:
Kellogg Company
Food Company:
Reviewer Comments:
  • The article does not mention how energy intake was assessed. 
  • There was no statistically significant change in energy intake from baseline compared to week eight.
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.) ???
  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? Yes
  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)? No
  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? N/A
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? No
  10.1. Were sources of funding and investigators' affiliations described? Yes
  10.2. Was the study free from apparent conflict of interest? No