Reviewer's report
 Initial evaluation of long-term weight maintenance in women 2 to 11 years following a commercial Title:
weight loss program.
Authors:
Caroline Gosselin (gosselin.cabanac@sympatico.ca )
Guylaine Cote (acc316@agora.ulaval.ca )
 2  18 Jul 2001 Version: Date:
 Dr JD Latner Reviewer:
 A paper whose findings are important to those with closely related research interests Level of interest:
 Accept after revision, which I do not need to see Advice on publication:
"Initial evaluation of weight loss maintenance in women two to eleven years following a commercial 
program," Caroline Gosselin, Ph.D., & Guylaine Cote, MSc 
This study examined the weight losses of individuals enrolled for 2 to 11 years in a Canadian 
commercial weight loss program. This initial report showed maintenance of weight losses over 5% in a 
subset of participants who remained in the program over the long-term, and provides preliminary 
support for the use of commercial weight loss programs. A particular strength of the study was the range of treatment lengths of participants, and the size of the sample that allowed this range. Detailed below are several recommendations to further strengthen the manuscript. 
1) Page 5, Line 18: please define "food sampling." 
2) Page 6, 1st paragraph of Methods section: Even though only those who had been enrolled for less 
than one month were excluded from analyses, the study seems to include only participant who were in 
Mincavi for at least 2 years. Were those who were in the program for less than 2 years excluded as 
well? If so, specify. 
3) Page 7, lines 7-10: Adjusting individuals' self-reported weights is a useful strategy. The authors have 
used a figure of 2.9% to correct for misreporting, based on Tell et al. Is this figure consistent with the discrepancies in the present sample, based on those participants whose weights were verified? It wouldbe helpful to report the discrepancy found for these 31 persons to provide further rationale for adjusting 
self-reported weights and for using 2.9% as the correction figure. If the discrepancy found here is very 
different from 2.9%, you could consider using it rather than Tell et al.'s figure. 
4) Page 9, 1st paragraph: This different may or may not be disproportionate. A chi-square test is 
recommended to examine whether the difference (again discussed in the Discussion section) is 
significant. 
5) Page 10, final sentence: The authors state that subjects represented the majority of individuals 
entering the program. This appears to be untrue based on the data reported. Subjects in the present 
study represented the majority of individuals currently in the program; however, like the Slovenian study
critiqued for its selective analysis in this section, the present study involved a highly selective sample of 
individuals who remained in the program as currently active members and did not drop out of treatment.
No attempt was made to follow-up individuals who did drop out, and no information is given about what proportion of the total participants (drop-outs plus those remaining) the present sample constitutes. Thisflaw must be acknowledged in the discussion section. If information on attrition rates is available, this 
should also be provided. 
6) Page 13, 2nd paragraph: The authors compare their data with the Anderson et al. study, which 
reported that 25% of all participants at 7 years maintaining a loss of 10%; however, the two analyses 
appear not to be parallel. The present study boasts that 37.8% of women maintained a 10% loss at 7 to 
11 years. However, this 37.8% is a percent of the total number of participants interviewed - only those 
still in treatment. This is not an intent-to-treat analysis, but merely a "completer" analysis of those who remained in treatment, and it is not comparable to a reference that includes all participants, completers 
and drop-outs (assuming that the Anderson reference is an intent-to-treat analysis). 
7) Page 14, line 5: Clarify "formulas." Nutritional formulas? 
8) Page 14, 1st full paragraph: The authors report that a proportion of individuals gained weight since 
starting the program. It would be interesting if the authors would speculate as to why this might have occurred. Could it be merely the effect of time? (Were these gains greater in the longer-term groups?) Or regression toward the mean, at least in those individuals who started at low weights? 
9) Page 15, lines 11-13: Although there is no established "average" (as the authors imply here) for 
weight losses of individuals enrolled in commercial programs between 2 and 11 years, there is a recent 
study on Weight Watchers of a very similar design, with which it would be informative to compare the 
current results: Lowe et al., (2001) Int. J. Obesity, 25, 325-331. 
10) Page 15, 4th line from bottom: "Knowing that "yo-yo" dieting has been demonstrated to be as much 
of a health risk as obesity is" - this is a strongly phrased statement considering the mixed evidence on 
this issue. I would recommend greater circumspection, perhaps something like "Considering the 
possible adverse effects of "yo-yo" dieting,..." 
11) Table 2: Columns 7-9, weight loss 15-19.9% through 25%+ could be consolidated into a single 
column of 15%+. The three separate columns seem unnecessary in light of the low numbers in each 
column. This would also help to de-clutter the table. In addition, the bottom row, number of subjects, is 
confusing because this only refers (I gather) to the number of subjects in the entire group. I recommend 
deleting this row and placing the numbers in each cell in the first row, "entire group," such that each cell 
would contain the percentage followed by the number: i.e., 22.7 (n = 66), 29.6 (n = 86), etc. 
12) Several minor corrections of syntax: page 5, line 1: change to "inexpensive"; line 3: join sentence 
with preceding or following paragraph; lines 5 & 6: change "around" to "approximately"; page 6, line 6: 
change "For that matter" to "For that reason". Page 2, line 5 and page 12, line 8: I believe you mean to 
say "effectiveness" and "effective" rather than "efficiency" and "efficient." 
Competing interests:
None declared.