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NAP: Energy Balance and Body Composition (2007)

Citation:

Mourier A, Bigard AX, deKerviler E, Roger B, Legrand H, Guezennec CY. Combined effects of caloric restriction and branched chain amino acid supplementation on body composition and exercise performance in elite wrestlers. Int J Sports Med. 1997; 18: 47-55.

PubMed ID: 9059905
 
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 investigate the effects of 19-day qualitatively and quantitatively varied energy intakes on body composition and exercise performance in elite male wrestlers. 
Inclusion Criteria:
Male wrestlers, highly-trained in prolonged exercise who had been "wrestling for many years."
Exclusion Criteria:
Anabolic steroid use.
Description of Study Protocol:

Recruitment

Wrestlers from the French National Institute of Sports

Design

  • Randomized controlled trial
  • Wrestlers randomly assigned to one of five dietary treatment groups described in the intervention for a 19-day period
  • Body composition and exercise performance measures taken pre- and post-intervention.  

Blinding Used

None specified.

Intervention
  • Normocaloric control (N=6) (C)
  • Hypocaloric control (N=6) (hC)
  • Hypocaloric high protein (n=7) (hHP)
  • Hypocaloric high branched chain amino acids (n=6) (hBCAA)
  • Hypocaloric low protein (n=6) (hLP).
Statistical Analysis
  • Time and diet effects were determined through two-way repeated-measures ANOVA
  • Comparisons between pre- and post- in each experimental group were determined through a paired Student's T-test
  • Dietary differences used an unpaired Student's T-test.
Data Collection Summary:

Timing of Measurements

Before and after a 19-day dietary intervention. 

Dependent Variables

  • Anthropometric measures (height, weight, BMI)
  • Skinfold thickness (calipers)
  • Body composition (MRI, Segmentation of Adipose Tissue)
  • VO2max (treadmill, arm ergometer)
  • Maximal voluntary isometric contraction (MVC, using right isometric knee extensions on an isokinetic dynamometer)
  • Anaerobic capacity (Wingate test)
  • Biochemical analysis (free fatty acids, peripheral thyroid hormones, serum growth hormone levels).

Independent Variables

  • Dietary changes (caloric level, protein level, use of BCAAs)
  • Subjects recorded their daily weighed-meals intake over seven successive days in notebooks
  • Total daily intake of energy, protein, carbohydrate and fat were estimated daily and averaged for one week.
Description of Actual Data Sample:
  • Initial N: 31 males
  • Attrition (final N): 31
  • Age: Mean age between 22 and 24 across all groups
  • Ethnicity: Not reported
  • Anthropometrics: See below; no significant differences between groups at baseline reported. 
  • Location: France.

 

Summary of Results:

  

 
C group
hC group
hHP group
hBCAA group
hLP group
Carbohydrate (%)
55
55
60
60
60
Protein (%)
12
12
25
20
15
Fat (%)
33
33
15
20
25
Energy intake (kcal/kg*day)
40
28
28
28
28

 
C group
hC group
 
Pre-diet
Post-diet
Pre-diet
Post-diet
Age (y)
22±4
22±4
23±4
23±4
Body weight (kg)
65.2±10.9
65.1±10.8b
82.7±9.9
80.8±10.1 b
BMI (kg/m2)
22.6±0.6
22.5±0.6
26.1±1.0
25.5±0.7
Body fat (%)
5.8±2.0
5.6±1.8
7.8±3.4
6.8±2.6bc
MRI (abdomen)
SAT (cm2)
20.4±3.5
21.1±5.0
53.7±8.1
44.6±6.9c
VAT (cm2)
55.5±0.5
55.9±1.0
60.2±1.5
51.8±1.5 bc
MRI (thigh)
AT (cm2)
17.3±3.8
16.9±3.8
32.2±3.6
28.3±3.0c
MT (cm2)
178.0±9.2
177.5±9.4
226.4±12.5
215.1±10.8

 
hHP group
hBCAA group
hLP group
 
Pre-diet
Post-diet
Pre-diet
Post-diet
Pre-diet
Post-diet
Age (y)
24±4
24±4
23±4
23±4
23±4
23±4
Body weight (kg)
75.9±10.1
73.5±10.2 b
74.4±11.1
70.4±10.4c
72.8±7.0
70.9±7.0b
BMI (kg/m2)
24.8±0.5
24.0±0.4
25.1±1.0
24.2±0.8
24.0±0.8
23.4±0.6
Body fat (%)
7.8±1.9
6.9±1.6bc
8.1±3.1
6.6±2.1c
6.9±1.4
6.2±1.4 b
MRI (abdomen)
SAT (cm2)
54.0±3.0
42.8±4.5
52.2±2.0
37.8±1.7c
51.9±9.8
42.6±9.9c
VAT (cm2)
59.4±2.4
45.9±2.1bc
56.3±1.6
36.9 ± 1.6c
56.5±6.9
44.9±1.9bc
MRI (thigh)
AT (cm2)
30.5±3.8
25.8±2.7
28.5±2.2
21.8±2.1
27.5±4.9
24.6±4.5c
MT (cm2)
208.2±12.9
193.3±8.9
208.7±10.5
200.9±10.3
207.4±10.5
193.9±8.9

 

No significant differences in performance measures between groups or within groups following any 19-day nutrition intervention.

 

 
C group
hC group
 
Pre-exercise
Post-exercise
Pre-exercise
Post-exercise
Before Diet
Glucose (mmol/L)
4.09±0.46
5.28±0.37
5.28±0.78
6.85±0.32
Insulin (mU/L)
16.02±3.15
22.23±5.66
20.94± 4.27
27.36±9.04
Lactate (mmol/L)
1.11±0.17
10.29±1.00a
2.12±0.26
10.75±1.48a
FFA (mmol/L)
0.12±0.02
0.30±0.07a
0.13v± 0.01
0.33±0.07a
Glycerol (mmol/L)
13.8±1.9
28.3±1.9a
15.4±2.4
38.8±1.2a
T3 (mU/L)
1.83±0.06
 
1.69±1.09
 
GH (mU/L)
0.87±0.11
13.96±7.39a
0.87±0.41
14.17±6.51a
After Diet
Glucose (mmol/L)
3.26±0.20
5.37±0.24a
3.69±0.41
5.05±0.59
Insulin (mU/L)
21.31±3.31
23.35±3.70
15.30±1.27
16.50±0.81
Lactate (mmol/L)
1.10±0.18
8.32±0.61a
1.18±0.17
8.84±1.42a
FFA (mmol/L)
0.13±0.01
0.30±0.07a
0.10±0.01
0.21±0.03a
Glycerol (mmol/L)
11.1±2.4
27.8±2.2 a
15.0±2.0
23.4±2.0a
T3 (mU/L)
1.83±0.06
 
1.77±0.09
 
GH (mU/L)
0.92±0.10
15.26±6.14ab
1.22±0.42bc
19.80±4.90ab

 
hHP group
hBCAA group
hLP group
 
Pre-diet
Post-diet
Pre-diet
Post-diet
Pre-diet
Post-diet
Before Diet
Glucose (mmol/L)
4.14±0.20
7.37±0.60a
4.43±0.32
7.52±0.36a
4.50±0.21
7.37±0.45a
Insulin (mU/L)
16.25±3.79
20.29±4.40
14.62±2.39
19.89±1.64
21.25±5.54
31.59±9.16
Lactate (mmol/L)
1.83±0.22
10.46±0.58a
2.33±0.24
10.54±1.00a
1.77±0.18
12.54±1.36a
FFA (mmol/L)
0.14±0.03
0.30±0.07
0.16±0.01
0.32±0.05a
0.13±0.06
0.19±0.02
Glycerol (mmol/L)
15.0±1.0
31.0±3.6a
14.0±2.9
35.0±4.1a
16.7±1.7
29.8±4.3a
T3 (mU/L)
1.81±0.08
 
1.87±1.08
 
1.70±0.14
 
GH (mU/L)
0.89±0.38
12.67±3.40a
0.77±0.57
14.00±3.98a
0.74±0.42
12.65±5.90a
After Diet
Glucose (mmol/L)
3.91±0.30
6.36±0.24a
3.63±0.23
6.13±0.35a
4.10±0.12
6.05±0.29a
Insulin (mU/L)
19.34±3.43
20.43±4.45
17.49±1.48
18.30±2.48
25.17±5.10
26.73±4.78
Lactate (mmol/L)
1.31±0.17
10.46±1.10a
1.83±0.34
9.73±1.40a
1.48±0.38
11.21±1.58a
FFA (mmol/L)
0.09±0.01
0.27±0.06a
0.12±0.01
0.18±0.02a
0.15±0.05
0.21±0.03a
Glycerol (mmol/L)
23.8±1.3
27.7±1.6a
22.8±1.4
25.3±2.5c
14.8±1.3
31.0±5.7a
T3 (mU/L)
1.58±0.09
 
1.68±0.06
 
1.73±0.13
 
GH (mU/L)
2.71±1.05c
25.81±3.10ac
2.85±0.03
26.30±3.43ac
0.90±0.10bc
15.87±1.98ab

 

a: Significant difference compared with pre-exercise vs post exercise values, P<0.05
b: Significant difference vs BCAA values, P<0.05
c: Significant difference compared with pre-diet values vs post diet value, P<0.05.

 

Author Conclusion:
  • Maintaining a high level of carbohydrate intake, no hypocaloric diets alter performance
  • Energy restriction diets induce a reduction in the body mass and favorable modifications in body composition
  • High-BCAA diet produces the highest losses in body fat.
Funding Source:
University/Hospital: Centre d'Etudes et de Recherches de Medecine Aerospatiale, Hopital Saint-Louis, Hopital Pitie-Salpetriere
Reviewer Comments:
  • Large variations in several measurements at baseline, although they weren't reported as significant
  • Small numbers of subjects in groups.  
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) No
  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? No
  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%.) ???
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? ???
  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? ???
  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.) Yes
  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? 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? Yes
  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? 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? 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