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MNT: Weight Management (2015)

Citation:
Conceicao de Oliveira M, Sichieri R, Moura AS. Weight loss associated with a daily intake of three apples or three pears among overweight women. Nutrition. 2003; 19: 253-256. PubMed ID: 12620529
 
Study Design:
Randomized Controlled Trial
Class:
A - Click here for explanation of classification scheme.
Quality Rating:
Neutral NEUTRAL: See Quality Criteria Checklist below.
Research Purpose:
To investigate the effect of adding fruit  to the diet on changes in body weight and serum cholesterol.
Inclusion Criteria:
  • Female
  • Overweight (BMI higher than 25kg/m2 )
  • Hypercholesteremic
  • Non-smoking
  • Aged 30 years to 50 years old.
Exclusion Criteria:
  • Diabetic
  • Taking medications or substances that would alter cholesterol levels
  •  Little affinity to apple, pears or cookies.
Description of Study Protocol:

Recruitment
 
Participants recruited from a primary care center of the State University of Rio de Janeiro, Brazil.

Design

Randomized clinical trial; no control group but three groups (apple, pear and oatmeal cookie).

Intervention

Participants randomized and instructed to consume either an apple (300g), pear (300g) or oat cookie (60g) three times per day as a snack between meals. Subjects met with a dietitian (at two and 12 weeks) and were instructed to consume a hypocaloric diet [55% energy from carbohydrate (CHO), 15% from protein and 30% from fat] for 12 weeks to reduce weight by 1kg per month. Energy adjustments were made every two weeks and the snacks were compensated for with an energy reduction of rice and beans. Three-day dietary records were completed after three weeks and 12 weeks of follow-up. Compliance to the diet was estimated by using food record and serum triacylglyercols and cholesterol. The two fruit groups were combined for analysis. 

Statistical Analysis

  • One-way ANOVA used to compare baseline characteristics of age, body weight, serum glucose and tryglicerides between those consuming fruit, cookies and those lost to follow-up
  • Paired T-tests used to compare changes in weight, serum glucose, fasting insulin and glucose:insulin ratio from baseline to 12 weeks
  • Mixed model used to account for the variance due to repeated measures between groups.
Data Collection Summary:

Timing of Measurements

Baseline to 12 weeks.

Dependent Variables

  • Weight: Researchers did not explicitly state how weight was measured  
  • Cholesterol: Measured in fasting state using standardized lab procedures
  • Serum glucose and triglycerides: Measured enzymatically.

Independent Variables

Diet group and time.
Description of Actual Data Sample:

Initial N

  • N=49 randomly assigned to participate
  • N=35 completed at 12 weeks (dropout rate 29%).

Attrition (Final N)

  • N=35 completed at 12 weeks (29% attrition)
  • Final N=26 in fruit group and nine in oat cookie group.

Age

  • Fruit group mean (SD): 43.7 (4.8)
  • Oat group: 45 (3.8)
  • Lost to follow-up: 43.9 (7.6)
  • P=0.86.
Anthropometrics and Clinical Variables at Baseline
 
  Fruit Group Oat Cookie Lost to Follow-up P-value
Weight (kg) 77.7 (10.6) 78.9 (9.7) 80.2 (11.3) 0.77
Serum glucose (mg per dL) 103 (38) 91 (10) 103 (47)0.63 0.72
Triglycerides (mm per L) 1.96 (0.79) 1.57 (0.36) 1.86 (0.85) 0.46
Fruit intake (U) 0.75 (0.64) 1.02 (0.77) 0.59 (0.63) 0.33

 

Location

Rio de Janeiro, Brazil.

Summary of Results:

Key Findings

  Baseline
Mean (SD)		 12-week
mean (SD)		 Mean change    CI P-value
Weight (kg)
 
Fruit (N=26)
Oat (N=9)
 		  
77.7 (10.8)
78.9 (9.7)		  
76.5 (11.2)
78.0 (9.1)		  
-1.21
-0.88		  
0.44 to -1.85
0.37 to 2.13		  
0.02
0.11
Serum glucose (mg per dL)

Fruit (N=25)
Oat (N=9)
 		  
 
96.6 (17.6)
91.5 (11.0)		  
 
94.5 (22.8)
90.7 (15.4)		  
 
-5.2
-0.75		  
 
NA		  
 
0.02
0.87
Fasting insulin (mcg per ml)

Fruit (N=26)
Oat (N=9)
 
 		  
12.3 (9.0)
6.3 (2.5)		   
16.7 (12.2)
11.6 (14.6)		  
 3.1
 5.3		  NA   
0.18
0.34
Glucose:insulin ratio

Fruit (N=25)
Oat (N=8)
 
 		  
11.0 (5.2)
16.7 (5.4)		  
8.9 (5.6)
13.7 (5.8)
-2.0
-3.0		  
NA		  
0.14
0.40

 

 

 

Author Conclusion:
Overweight, hypercholesterolemic women have important changes in body weight and metabolic profiles from the addition of fruits to their diets.
Funding Source:
Industry:
Commodity Group:
University/Hospital: Policlinica Piquet Carneiro, Instituto de Medicina Social, UERJ, and Hospital Universitaro Pedro Ernesto
Other: Associacao Brasileira de Produtores de Maca and the Coordenadoria de Aperfeicoamento de Pessoal de Nivel Superior
Reviewer Comments:
  • Small and uneven sample sizes used to make comparisons using parametric tests; mention of transformation of measures
  • No real control group
  • Relatively large dropout rate, particularly for the oat cookie group
  • Authors state there was a significant difference in weight in the fruit group because the CI did not cross zero; however, they provide the CI as 0.4 to -1.85.
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? No
  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? No
  2.4. Were the subjects/patients a representative sample of the relevant population? No
3. Were study groups comparable? No
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) No
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? ???
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) No
  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? ???
  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? No
  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? No
  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? No
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? No
  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? ???
  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? 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? No
  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)? No
  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? No
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