Retention rates and weight loss in a commercial weight loss program

Abstract

To evaluate and describe retention rates and weight loss in clients participating in a commercial weight loss program.
A total of 60 164 men and women ages 18-79 years who enrolled in the Jenny Craig Platinum program between May 2001 and May 2002.
Retention rates, mean weight loss and percent weight loss were calculated on a weekly basis for the 52-week period following initial enrollment in the weight loss program. Clients were categorized based on final week of participation in the program (weeks 1-4, weeks 5-13, weeks 14-26, weeks 27-39 and weeks 40-52) and weight loss was calculated at final week. A subgroup of clients was identified based on attendance through 13, 26 and 52 weeks. Mean and percent weight loss was calculated for these subgroups of clients.
Of the 60 164 men and women who enrolled in the weight loss program, 73% were retained in the program after 4 weeks, 42% at 13 weeks, 22% at 26 weeks and 6.6% at 52 weeks. Clients who dropped out of the program during the first 4 weeks lost 1.1+/-1.6% (mean+/-s.d.) of their initial body weight, whereas clients who dropped out between 40 and 52 weeks lost 12.0+/-7.2%. Clients in the 13-week, 26-week and 52-week cohorts lost 8.3+/-3.3, 12.6+/-5.1 and 15.6+/-7.5% of their initial body weight, respectively.
Weight loss was greater among clients who were retained in the program longer. The findings from this study suggest that a commercial weight loss program can be an effective weight loss tool for individuals who remain active in the program.

Full text

ORIGINAL ARTICLE
Retention rates and weight loss in a commercial
weight loss program
CE Finley
1
, CE Barlow
1
, FL Greenway
2
, CL Rock
3
, BJ Rolls
4
and SN Blair
1
1
The Cooper Institute, Center for Epidemiologic Research, Dallas, TX, USA;
2
Pennington Biomedical Research Center,
Outpatient Clinic Unit, Baton Rouge, LA, USA;
3
Department of Family and Preventive Medicine, University of California,
San Diego Medical Center, La Jolla, CA, USA and
4
Department of Nutritional Sciences, Penn State University, University
Park, PA, USA
Objective: To evaluate and describe retention rates and weight loss in clients participating in a commercial weight loss program.
Subjects: A total of 60 164 men and women ages 18–79 years who enrolled in the Jenny Craig Platinum program between May
2001 and May 2002.
Methods: Retention rates, mean weight loss and percent weight loss were calculated on a weekly basis for the 52-week period
following initial enrollment in the weight loss program. Clients were categorized based on final week of participation in the
program (weeks 1–4, weeks 5–13, weeks 14–26, weeks 27–39 and weeks 40–52) and weight loss was calculated at final week. A
subgroup of clients was identified based on attendance through 13, 26 and 52 weeks. Mean and percent weight loss was
calculated for these subgroups of clients.
Results: Of the 60 164 men and women who enrolled in the weight loss program, 73% were retained in the program after 4
weeks, 42% at 13 weeks, 22% at 26 weeks and 6.6% at 52 weeks. Clients who dropped out of the program during the first 4
weeks lost 1.171.6% (mean7s.d.) of their initial body weight, whereas clients who dropped out between 40 and 52 weeks lost
12.077.2%. Clients in the 13-week, 26-week and 52-week cohorts lost 8.373.3, 12.675.1 and 15.677.5% of their initial
body weight, respectively.
Conclusion: Weight loss was greater among clients who were retained in the program longer. The findings from this study
suggest that a commercial weight loss program can be an effective weight loss tool for individuals who remain active in the
program.
International Journal of Obesity advance online publication, 6 June 2006; doi:10.1038/sj.ijo.0803395
Keywords: commercial weight loss program; retention rates; weight management
Introduction
The growing prevalence of obesity and overweight has
increased the need to find effective weight loss programs.
For men and women who are overweight or obese, a modest
weight loss of 5–10% of their body weight can lead to
significant decreases in the co-morbidities associated with
overweight and obesity.
1,2
In the US population, estimates of
the prevalence of attempts to lose weight range from 38 to
44% in women and 24 to 29% in men.
3,4
Americans spend
over $33 billion annually on a variety of weight loss products
and services.
5
These weight loss services range from self-help
attempts at dieting or physical activity, professional counsel-
ing, pharmacological interventions and surgical interven-
tions to commercial weight loss programs with and without
structured diets.
The number of commercial weight loss programs has
increased to meet the need of consumers, but recent reviews
of commercial weight loss programs have exposed the lack of
scientific, peer-reviewed data from most programs.
6,7
In their
review, Tsai and Wadden
7
suggested that prominent com-
mercial weight loss programs should carry out ‘naturalistic
studies’ following a large cohort to determine retention rates
and weight loss at discontinuation. Such studies would
provide consumers with adequate information to make
informed decisions about a commercial weight loss program
before joining. To address the relative lack of ‘naturalistic
studies’ from commercial weight loss programs that has been
identified in recent reviews, we performed analyses using
data from a commercial weight loss program. The purpose of
the study is to present data from a ‘naturalistic study’ of one
Received 12 October 2005; revised 31 March 2006; accepted 10 April 2006
Correspondence: CE Finley, The Cooper Institute, 12330 Preston Road, Dallas,
TX 75230, USA.
E-mail: cfinley@cooperinst.org
International Journal of Obesity (2006) 1–7
&
2006 Nature Publishing Group All rights reserved 0307-0565/06
$
30.00
www.nature.com/ijo

commercial program, with the view that this information
may be useful to health-care professionals and individuals
seeking support for weight management. The specific
objectives of this study were to evaluate retention rates and
weight loss in clients participating in the weight loss
program and to identify cohorts of committed clients based
on attendance through 13, 26 and 52 weeks of the program
and document their weight loss experiences.
Participants and methods
The weight loss program
Jenny Craig was established in 1983 with a mission to help
clients achieve their weight management goals through a
behavioral change approach, including healthy eating, an
active lifestyle and a balanced approach to living. The
program, designed by registered dietitians in consultation
with a multidisciplinary Medical Advisory Board, consists of
weekly one-on-one meetings with a trained consultant at a
community-based facility who tailors the program to the
client’s food, menu and physical activity preferences while
providing behavioral strategies to develop a balanced life-
style for long-term weight management. Consultants also
provide follow-up telephone and e-mail contacts with the
clients along with Website/message board availability. Con-
sultants help clients choose a realistic goal weight, based on
their current weight and a healthy weight that corresponds
to a body mass index range of 18.5–24.9 kg/m
2
and provide
advice on how to increase physical activity. The program is
designed to result in an average weight loss of 1 to 2 pounds
per week to reach the client’s goal weight. There is no
minimum or maximum weight restriction for clients enrol-
ling in the program because desired weight loss may range
from 5 pounds to over 100 pounds depending on the client’s
needs. The average cost of enrolling in the program during
the time period of the study was $180, with enrollment costs
ranging from $20 to $399 depending on promotions and
discounts. In addition to the cost of enrollment, clients
typically spend about $20 to $30 more per week on food
when active in the program as compared to when they are
off the program. This compares with data from the
Consumer Expenditure Survey, which estimates that US
consumers typically spend $59 per week on food.
8
An
estimate of the cost of the program for a 1-year membership
is $1480, which includes enrollment and weekly food costs
that are above what consumers would typically spend on
food.
The healthy eating component of the diet and lifestyle
modification program consists in defining an energy-
reduced diet of 1200–2000 kcal/day based on the client’s
energy requirements. This plan includes prepackaged pre-
pared food items and incorporates meal additions such as
vegetables, fruit and whole grains to help reduce the overall
energy density of the diet. The prepackaged foods are
generally provided at the weekly meeting with the con-
sultant, and food selections are determined by the prefer-
ences of the client and how well they fit into the overall meal
plan. Clients also receive counseling for making appropriate
food choices in situations outside the context of prepackaged
foods (e.g., eating in restaurants, eating when traveling,
meals and snacks based on usual food choices).
Consultants also counsel clients on increasing physical
activity by setting realistic goals that are based on the
readiness, capabilities and preferences of the client. In
general, the goal is for clients to accumulate at least 30 min
of physical activity on 5 or more days of the week, based on
recommendations from the Centers for Disease Control and
Prevention, the American College of Sports Medicine
9
and
the office of the US Surgeon General.
10
This commercial
program utilizes extensive written materials and other
media, such as CDs that promote increasing physical activity
and videotapes to facilitate structured exercise activities.
The present study includes participants from the Platinum
Program. The Platinum Program is a year-long program in
which clients receive additional incentives to remain active
in the program such as a walking audio program, a
cookbook, and discounts for family members.
Participants
Clients eligible for the study were 65 154 men and women
ages 18–79 years who enrolled in the Platinum Program in
the United States between May 2001 and May 2002.
Employees of the company and clients interested in main-
taining weight rather than losing weight (defined as
‘Maintenance’ clients by the company) were not included
in the sample for the analyses presented here. Of those
initially eligible to be included in the analyses, 139 were
excluded owing to unreliable baseline weight and 4851 were
excluded owing to unrealistic weekly weight loss, defined as
a change in weight of 15 pounds or more in 1 week, leaving
60 164 men and women in the study.
Data collection
A trained consultant obtained baseline weight and calcu-
lated a goal weight when the client registered for the
program. Weight data were entered into a computer program
for tracking purposes. Weight measurements were obtained
when the client returned for the weekly one-on-one
consultation. We are limited in the amount of demographic
data available for the analysis owing to variations in data
collection practices over time and across community centers.
Approximately, 25% of clients are missing data on gender,
20% on age, 33% on marital status and 66% on occupation.
For this reason, retention rates and weight loss data are
pooled for men and women and stratification by demo-
graphic variables is not shown for some of the analyses.
Data analysis
We calculated retention rates on a weekly basis for the
52-week period following initial enrollment. Clients were
Retention in a commercial weight loss program
CE Finley et al
2
International Journal of Obesity

considered dropouts if they had missing weight data for 6 or
more consecutive weeks during the 52-week period. If the
client was a dropout, the final week was defined as the last
week with weight data before missing 6 or more consecutive
weeks. We calculated mean and percent weight loss at the
final week for all clients. We then categorized clients into
groups based on their percent weight loss and calculated
mean and median weight for the final week and determined
if retention differed between groups. The following group-
ings were used: clients who lost o5, 5–10, 10.1–15, 15.1–20
and 420% of their baseline weight. We tested for differences
across groups using analysis of variance.
We identified clients with a high level of commitment to
the program based on attendance at three different time
periods. To be included in the 13-, 26-, or 52-week cohort,
clients must have attended at least 85% of their weekly
consultations during the initial 13-week period (11 of 13
consultations), 26-week period (23 of 26 consultations) or
52-week period (46 of 52 consultations), respectively. For this
subanalysis, we excluded clients with missing data on
gender. We calculated mean weight at baseline, and mean
weight loss and percent weight loss at follow-up stratified by
gender for each cohort. All data analyses were conducted
with SAS version 8.2 (SAS Institute, Cary, NC, USA, 1999).
Results
Retention rates for all clients are shown in Figure 1. Of the
60 164 men and women who began the program, 73% were
retained in the program after 4 weeks (1 month), 42%
remained at 13 weeks (3 months), 22% at 26 weeks (6
months) and 6.6% were retained in the program for 52
weeks. After 10 weeks in the program, 50% of the
participants had dropped out of the program, although
specific data on the reason for discontinuing in the program
are not available in this data set.
The mean baseline weight for the 60 164 men and women
in the study was 89.8721.2 kg (mean7s.d.) and the mean
weight loss during participation in the program was
5.075.5 kg. Percent weight loss is directly associated with
the amount of time a client remains in the program
(Figure 2). Mean baseline weight, mean weight loss and
percent weight loss at dropout or last measurement was
significantly greater for clients who remained in the program
longer (Table 1). Clients who dropped out of the program
during the first 4 weeks lost about 1% of their initial body
weight compared with about 12% weight loss for clients who
remained in the program at least 40 weeks (P for trend:
o0.0001). Clients who dropped out of the program between
weeks 14 and 26 (4–6 months) lost an average of 7.3% of
their baseline body weight, a meaningful weight loss for
reducing health risks associated with overweight and obesity.
When we stratified by percent of baseline weight loss, 56%
of clients had a weight loss of less than 5% of their baseline
weight, whereas 26.5% lost 5–10% of their baseline weight
and 17.5% lost over 10% of their baseline weight (Table 2).
The mean final week for clients who lost less than 5% of their
baseline weight was 8.5 weeks, compared with 20.5 weeks for
clients who lost between 5 and 10% of their baseline weight
and 31 weeks for clients who lost 10.1–15% of their baseline
weight.
Mean weight loss for the 13-, 26- and 52-week cohorts by
gender are shown in Tables 3 and 4. Women and men
experienced similar weight loss trends in all cohorts. Clients
in the 52-week cohort had a larger baseline weight and
weight loss compared to clients in the 13- and 26-week
cohorts. Women and men who attended at least 11 of their
consultations at 13 weeks lost approximately 8% of their
body weight. Men and women in the 26-week cohort lost
0
10
20
30
40
50
60
70
80
90
100
0
2
4
6
8
10
12
14
16
18
20
22
24
26
28
30
32
34
36
38
40
42
44
46
48
50
52
Weeks
Figure 1 Percentage of 60 164 clients retained at each week during a 52-week time period.
Retention in a commercial weight loss program
CE Finley et al
3
International Journal of Obesity

approximately 12% of their baseline weight. Clients in the
52-week cohort experienced the greatest weight loss, with
women losing about 16% and men losing about 13% of their
baseline weight. All three cohorts experienced a greater
weight loss compared to the entire client sample.
Discussion
Retention is directly associated with weight loss in this study
of clients enrolled in the commercial diet and lifestyle
modification program between May 2001 and May 2002.
Although attrition in the study was high, those who
remained in the program longer lost more weight. Clients
who lost between 10.1 and 15% of baseline weight remained
active in the program an average of 31 weeks. Clients who
remained in the program longer also had a higher baseline
weight suggesting that weight loss and retention may also be
related to baseline weight, perhaps because these individuals
had more weight to lose to reach their goal weight and thus
took more time to achieve a weight that was acceptable to
them. Additionally, clients who displayed greater commit-
ment to the program as evidenced by higher attendance rates
at weekly consultations lost more weight compared with
clients who were less committed.
The attrition rates among clients in this study are similar
to previously published studies of commercial weight loss
programs, although higher than those observed in con-
trolled clinical trials.
11–16
Volkmar et al.
17
found high
attrition rates in a study of 108 women enrolled in a
commercial weight loss program. In their study, 50% of the
women had dropped out of the program by 6 weeks and 70%
by 12 weeks. By comparison, a larger percentage of clients in
the present analyses were retained at both 6 and 12 weeks.
Approximately, 32% of the clients were no longer active in
the program at 6 weeks and 53% had dropped out by 12
weeks. Data on the reason for dropout or reason for
0
2
4
6
8
10
12
14
0
2
4
6
8
10
12
14
16
18
20
22
24
26
28
30
32
34
36
38
40
42
44
46
48
50
52
Weeks
Percent Weight Loss
Figure 2 Percent weight loss at final week of attendance for 60 164 clients.
Table 1 Mean and percent weight loss for 60 164 clients by final week of attendance
Final week N Baseline weight (kg) Weight loss (kg) Percent weight loss
Mean7s.d. Mean7s.d. Mean7s.d.
Weeks 1–4 (month 1) 16 465 89.4721.9 1.071.5 1.171.6
Weeks 5–13 (months 2–3) 18 377 89.3721.2 3.872.9 4.373.0
Weeks 14–26 (months 4–6) 12 042 89.6720.4 6.674.4 7.374.5
Weeks 27–39 (months 7–9) 5698 90.8720.8 8.575.8 9.475.6
Weeks 40–52 (months 10–12) 7582 93.3721.4 11.578.2 12.377.2
P for trend o0.0001 o0.0001 o0.0001
Table 2 Mean and median final week of attendance for 60 164 clients
stratified by percent weight loss group
Percent weight loss
group
N (%) Final week
mean7s.d.
Final week median
o5 33760 (56.1) 8.5710.5 5
5–10 15929 (26.5) 20.5713.8 16
10.1–15 6716 (11.2) 31.0714.3 28
15.1–20 2468 (4.1) 38.9712.7 41
420 1291 (2.2) 45.679.7 52
P for trend: o0.0001
Retention in a commercial weight loss program
CE Finley et al
4
International Journal of Obesity

remaining in the program are not available for these clients,
but based on other data from this commercial program,
potential reasons for leaving the program include cost,
scheduling conflicts/travel, tiring of the food, unrelated
health issues, meeting weight loss goals and/or stopped
losing weight. Customer satisfaction data collected by the
company suggest that clients remain in the program because
of the convenient, healthy meal options and the personal
accountability required of one-on-one weekly meetings with
a consultant. Published data on retention and attrition in
weight loss programs are generally based on smaller sample
sizes and shorter follow-up periods.
17–20
Lowe et al.
20
reported an attrition rate of 37% in 985 study participants
assigned to a 4-week Weight Watchers intervention, com-
pared to a 27% attrition in the present study. A strength of
our study is the large sample size of free-living men and
women studied over a 52-week period, which may offer a
realistic view of retention rates among clients who enroll in
commercial weight loss programs.
The National Institutes of Health clinical guidelines for the
treatment of overweight and obesity state that the goal of
weight loss therapy should be to reduce body weight by 10%
from baseline with a weight loss ranging from
1
2
to 2
pounds per week over a 6-month period.
1
In our study,
17.8% of the clients lost more than 10% of their baseline
weight, whereas 26.5% lost between 5 and 10% of their
baseline weight. Data from the Diabetes Prevention Program
demonstrate that a 7% weight loss, in addition to an increase
in physical activity and other dietary changes, results in a
58% reduction in risk of developing diabetes.
2
Approxi-
mately, 49% of participants in the Diabetes Prevention
Program achieved the recommended 7% weight reduction
after 24 weeks of the carefully controlled and intensive
intervention.
21
In comparison, clients in our study who
dropped out of the program between weeks 14 and 26 lost
7.3% of their baseline weight, which is an amount that
should provide important health benefits, whereas those
who remained in the study beyond 26 weeks lost signifi-
cantly more weight. Additionally, highly motivated clients
who attended at least 11 consultations by week 13 had a
mean weight loss of over 8% of baseline weight and women
and men who demonstrated a high level of commitment to
the program at 26 weeks lost more than 12% of baseline
weight.
The findings in the present study are consistent with
results from other studies of commercial weight loss
programs and suggest that this program can be an effective
weight loss tool for individuals who remain in the program
for at least 14 weeks. These clients lost more than 7% of their
baseline weight at an estimated cost of $400 through 14
weeks, including enrollment costs and additional food costs
that are above typical weekly food expenditures. Published
results from the Weight Watchers program show weight loss
ranging from 1.9 kg at 4 weeks
20
to 5.0 kg at 1 year.
22
These
results may differ owing to the number of participants, the
length of follow-up and differences in the population.
Investigators studying the Take Off Pounds Sensibly (TOPS)
program reported a weight loss of 14.2 pounds (6.5 kg) in 560
participants at 1 year.
23
Clients in the current study who
remained active at 52 weeks lost about 12.6 kg, although this
represents only 6.6% of the study population.
The study has limitations that may hinder the interpret-
ability of the data. The high attrition rate observed in the
study makes it difficult to determine the effectiveness of the
program. Clearly, clients who remain in the program
experience clinically significant weight loss, but because
the reasons for dropout are unknown it is difficult to describe
differences between those who dropped out and those who
remained active in the program. Also, we are unable to
determine which aspects of the program (i.e., one-on-one
Table 3 Mean weight loss for the 13-, 26- and 52-week cohorts – women
13-week cohort 26-week cohort 52-week cohort
N ¼ 14 730 N ¼ 5167 N ¼ 1471
Mean7s.d. Mean7s.d. Mean7s.d.
Baseline weight (kg) 90.07719.76 92.93720.11 96.48721.43
Follow-up weight (kg) 82.58718.41 81.12717.73 80.93717.37
Weight loss at follow-up (kg) 7.4973.38 11.8175.75 15.5679.37
Percent weight loss (%) 8.3173.25 12.5775.09 15.6177.54
Table 4 Mean weight loss for the 13-, 26- and 52-week cohorts – men
13-week cohort 26-week cohort 52-week cohort
N ¼ 1204 N ¼ 441 N ¼ 140
Mean7s.d. Mean7s.d. Mean7s.d.
Baseline weight (kg) 114.43722.29 118.47723.53 123.12725.08
Follow-up weight (kg) 104.29720.69 103.58720.48 106.34721.07
Weight loss at follow-up (kg) 10.1474.64 14.8977.90 16.77710.50
Percent weight loss (%) 8.8473.55 12.3975.41 13.2576.73
Retention in a commercial weight loss program
CE Finley et al
5
International Journal of Obesity

consultations, the structured diet, lifestyle counseling and/or
physical activity) are most effective in producing weight loss.
We do not have access to demographic data on a large
percentage of the population and, therefore, are limited in
the types of analyses we can perform. Future data collection
efforts should follow a standardized protocol and include a
complete ascertainment of baseline characteristics and
demographic data in addition to starting weight, such as
height, sex, marital status, income level, occupation and a
basic medical history. The addition of these data would allow
for better characterization of the clients who join commer-
cial weight loss programs and better understanding of the
factors that influence success in the program. Additional
baseline and demographic data would also enable more
accurate comparisons of clients who enroll in different
commercial weight loss programs. Finally, more complete
data on reasons for dropping out or for remaining in the
program would be beneficial.
Although the time period of the study is adequate to
describe the weight loss experience of clients in the program,
lack of data on weight loss maintenance is a limitation of the
study. In a previously published study, Wolfe
24
found that
82% of 267 Jenny Craig clients interviewed in a phone
survey remained within 10% of their post-treatment weight
after a mean follow-up of 56.8 weeks. Weight Watchers
reported that 19.4% of 1002 successful participants who
met their goal weight during the program were still within
5 pounds of their goal weight 5 years later.
25
Among 192
participants in the OPTIFAST program, 57% of participants
had maintained 5% or more of their weight loss after 3 years
of follow-up.
26
Although results from the current study are
promising, additional follow-up studies on a large cohort of
clients who have completed the program would provide
information on the program’s ability to help clients main-
tain their initial weight loss.
The data presented here can be used by health-care
professionals and individuals to characterize the average
retention and success rates experienced by clients in the
program. This information may be useful in decision making
regarding how to select a weight management approach. In
comparison to more cost-prohibitive weight loss options
such as hospital-based or medically supervised programs,
commercial weight loss programs provide easily accessible
options for individuals seeking to lose weight while provid-
ing strategies to develop a balanced lifestyle that incorpo-
rates healthy eating and physical activity.
Acknowledgements
We thank Andy Belden of Fulcrum Analytics for providing
the data for the study. We also thank Melba Morrow for her
editorial assistance in preparing the manuscript. This study
was supported by an unrestricted research grant from Jenny
Craig, Incorporated to The Cooper Institute.
References
1 National Institutes of Health. Clinical guidelines on the identifica-
tion, evaluation, and treatment of overweight and obesity in adults:
The evidence report. National Institute of Health: Rockville, MD,
1998, pp 1–228.
2 Knowler WC, Barrett-Connor E, Fowler SE, Hamman RF, Lachin
JM, Walker EA et al. Reduction in the incidence of type 2 diabetes
with lifestyle intervention or metformin. N Engl J Med 2002; 346:
393–403.
3 Kruger J, Galuska DA, Serdula MK, Jones DA. Attempting to lose
weight: specific practices among US adults. Am J Prev Med 2004;
26: 402–406.
4 Serdula MK, Mokdad AH, Williamson DF, Galuska DA, Mendlein
JM, Heath GW. Prevalence of attempting weight loss
and strategies for controlling weight. JAMA 1999; 282:
1353–1358.
5 Cleland R, Graybill DC, Hubbard V, Khan LK, Stern JS, Wadden TA
et al. Commercial weight loss products and programs: what
consumers stand to gain and lose. Washington DC, Federal Trade
Commission, Bureau of Consumer Protection 1998.
6 Hamilton M, Greenway F. Evaluating commercial weight loss
programmes: an evolution in outcomes research. Obes Rev 2004;
5: 217–232.
7 Tsai AG, Wadden TA. Systematic review: an evaluation of major
commercial weight loss programs in the United States. Ann Intern
Med 2005; 142: 56–66.
8 US Bureau of Labor Statistics. US Department of Labor. Consumer
Expenditure Survey, 2003–2004. US Bureau of Labor Statistics:
Washington, D.C., 2005.
9 Pate RR, Pratt M, Blair SN, Haskell WL, Macera CA, Bouchard C
et al. Physical activity and public health: a recommendation from
the Centers for Disease Control and Prevention and the American
College of Sports Medicine. JAMA 1995; 273: 402–407.
10 US Department of Health and Human Services. Physical activity
and health: A report of the Surgeon General. US Department of
Health and Human Services, Centers for Disease Control and
Prevention, National Center for Chronic Disease Prevention and
Health Promotion: Atlanta, GA, 1996.
11 Wing RR, Venditti E, Jakicic JM, Polley BA, Lang W. Lifestyle
intervention in overweight individuals with a family history of
diabetes. Diabetes Care 1998; 21: 350–359.
12 Davidson MH, Hauptman J, DiGirolamo M, Foreyt JP, Halsted
CH, Heber D et al. Weight control and risk factor reduction in
obese subjects treated for 2 years with orlistat: a randomized
controlled trial. JAMA 1999; 281: 235–242.
13 Jakicic JM, Winters C, Lang W, Wing RR. Effects of intermittent
exercise and use of home exercise equipment on adherence,
weight loss, and fitness in overweight women: a randomized trial.
JAMA 1999; 282: 1554–1560.
14 Jakicic JM, Marcus BH, Gallagher KI, Napolitano M, Lang W.
Effect of exercise duration and intensity on weight loss in
overweight, sedentary women: a randomized trial. JAMA 2003;
290: 1323–1330.
15 Wirth A, Krause J. Long-term weight loss with sibutramine: a
randomized controlled trial. JAMA 2001; 286: 1331–1339.
16 Zemel MB, Thompson W, Milstead A, Morris K, Campbell P.
Calcium and dairy acceleration of weight and fat loss during
energy restriction in obese adults. Obes Res 2004; 12: 582–590.
17 Volkmar FR, Stunkard AJ, Woolston J, Bailey RA. High attrition
rates in commercial weight reduction programs. Arch Intern Med
1981; 141: 426–428.
18 Honas JJ, Early JL, Frederickson DD, O’Brien MS. Predictors of
attrition in a large clinic-based weight-loss program. Obes Res
2003; 11: 888–894.
19 Teixeira PJ, Going SB, Houtkooper LB, Cussler EC, Metcalfe LL,
Blew RM et al. Pretreatment predictors of attrition and successful
weight management in women. Int J Obes Relat Metab Disord
2004; 28: 1124–1133.
Retention in a commercial weight loss program
CE Finley et al
6
International Journal of Obesity

20 Lowe MR, Miller-Kovach K, Frye N, Phelan S. An initial
evaluation of a commercial weight loss program: short-term
effects on weight, eating behavior, and mood. Obes Res 1999; 7:
51–59.
21 Wing RR, Hamman RF, Bray GA, Delahanty L, Edelstein SL, Hill
JO et al. Achieving weight and activity goals among diabetes
prevention program lifestyle participants. Obes Res 2004; 12:
1426–1434.
22 Heshka S, Anderson JW, Atkinson RL, Greenway FL, Hill JO,
Phinney SD et al. Weight loss with self-help compared with a
structured commercial program: a randomized trial. JAMA 2003;
289: 1792–1798.
23 Garb JR, Stunkard AJ. Effectiveness of a self-help group in obesity
control. A further assessment. Arch Intern Med 1974; 134: 716–720.
24 Wolfe BL. Long-term maintenance following attainment of goal
weight: a preliminary investigation. Addict Behav 1992; 17: 469–477.
25 Lowe MR, Miller-Kovach K, Phelan S. Weight-loss maintenance in
overweight individuals one to five years following successful
completion of a commercial weight loss program. Int J Obes Relat
Metab Disord 2001; 25: 325–331.
26 Grodstein F, Levine R, Troy L, Spencer T, Colditz GA, Stampfer MJ.
Three-year follow-up of participants in a commercial weight loss
program: can you keep it off? Arch Intern Med 1996; 156: 1302–
1306.
Retention in a commercial weight loss program
CE Finley et al
7
International Journal of Obesity