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Tate DF, Wing RR, Winett RA. Using Internet Technology to Deliver a Behavioral Weight Loss Program. JAMA. 2001;285(9):1172–1177. doi:10.1001/jama.285.9.1172
Context Rapid increases in access to the Internet have made it a viable mode
for public health intervention. No controlled studies have evaluated this
resource for weight loss.
Objective To determine whether a structured Internet behavioral weight loss program
produces greater initial weight loss and changes in waist circumference than
a weight loss education Web site.
Design Randomized, controlled trial conducted from April to December 1999.
Setting and Participants Ninety-one healthy, overweight adult hospital employees aged 18 to 60
years with a body mass index of 25 to 36 kg/m2. Analyses were performed
for the 65 who had complete follow-up data.
Interventions Participants were randomly assigned to a 6-month weight loss program
of either Internet education (education; n = 32 with complete data) or Internet
behavior therapy (behavior therapy; n = 33 with complete data). All participants
were given 1 face-to-face group weight loss session and access to a Web site
with organized links to Internet weight loss resources. Participants in the
behavior therapy group received additional behavioral procedures, including
a sequence of 24 weekly behavioral lessons via e-mail, weekly online submission
of self-monitoring diaries with individualized therapist feedback via e-mail,
and an online bulletin board.
Main Outcome Measures Body weight and waist circumference, measured at 0, 3, and 6 months,
compared the 2 intervention groups.
Results Repeated-measures analyses showed that the behavior therapy group lost
more weight than the education group (P = .005).
The behavior therapy group lost a mean (SD) of 4.0 (2.8) kg by 3 months and
4.1 (4.5) kg by 6 months. Weight loss in the education group was 1.7 (2.7)
kg at 3 months and 1.6 (3.3) kg by 6 months. More participants in the behavior
therapy than education group achieved the 5% weight loss goal (45% vs 22%; P = .05) by 6 months. Changes in waist circumference were
also greater in the behavior therapy group than in the education group at
both 3 months (P = .001) and 6 months (P = .005).
Conclusions Participants who were given a structured behavioral treatment program
with weekly contact and individualized feedback had better weight loss compared
with those given links to educational Web sites. Thus, the Internet and e-mail
appear to be viable methods for delivery of structured behavioral weight loss
Developing effective weight loss programs that are widely accessible
is a health care priority given that more than 54% of US adults are overweight
or obese1 and that weight loss is recommended
to reduce the health impact of obesity. Although group behavioral programs
involving weekly clinic visits are the most effective treatments available
for obesity, most adults would prefer to lose weight without having to participate
in a structured face-to-face treatment program.2
To accommodate the needs of these individuals and to make obesity treatment
more accessible, investigators have explored alternative methods for delivering
weight loss programs including mail-based correspondence programs3-5 interventions delivered
via telephone6 and television.7,8
Although these types of programs have typically produced smaller weight losses
than standard group behavioral programs, they offer an important alternative
to face-to-face treatment.
In the past decade, computer-mediated interventions have been developed
for a variety of behavior changes, including dietary change,9,10
smoking cessation,11 and exercise12;
however, few studies have been conducted using computers for the treatment
of obesity. Initial research in this area focused on using hand-held computers
for entry of self-monitoring data, to give automated feedback about caloric
values and either provide praise for or instructions on modifying eating contingent
on performance.13,14 Furthermore,
research has not expanded or developed the use of this technology as stand-alone
obesity treatment or as an adjunct to standard therapy. Computer based programs
can easily be adapted for use via the Internet, which has renewed interest
in using this technology for weight loss.
Rapid increases in access to the Internet and the World Wide Web has
made it a viable and logical mode for public health intervention. The number
of US adults who use the Internet has surged from 9% to 56% of adults in the
past 4 years.15 Conceptually, the Internet
has distinct advantages for program delivery because it combines the essential
characteristics of the other forms of media. For example, the Internet allows
for dissemination of written material, video or photographic materials, and
direct communication and social support via e-mail, bulletin boards, or chat
rooms. There are numerous Internet sites offering weight loss information
and providing such tools as databases of recipes or caloric values, diaries
for recording consumption and exercise, and bulletin boards to offer support.
Despite the proliferation of weight loss–related Web sites, no controlled
studies have evaluated this type of resource for weight loss.
After review of numerous Web sites, it appeared that although much of
the content of behavioral weight loss programs was covered on the Web, weight
loss Web sites lacked the programmatic nature, structure, and professional
contact that are essential elements of face-to-face clinic programs. We hypothesized
that better weight loss might be produced by using the Internet to deliver
a structured behavioral weight loss program including a sequence of 24 weekly
lessons that taught behavioral principles related to weight loss, weekly submission
of self-monitoring diaries, weekly recommendations from a therapist, and the
opportunity for social support among group members. To test this hypothesis
we conducted a randomized controlled trial to test the feasibility and initial
efficacy of a structured Internet behavioral weight loss program compared
with an educational Web site that was representative of weight loss resources
widely available on the Internet.
Ninety-one (81 women, 10 men) healthy overweight adults with a mean
(SD) age of 40.9 (10.6) and body mass index (BMI) of 29.0 (3.0) kg/m2, all employed by a large network of hospitals with access to e-mail
and the Internet, were recruited through a series of 2 e-mail messages and
an advertisement posted to the work site's Intranet Web site (Figure 1). The e-mail messages and advertisement clearly stated
the eligibility criteria. Interested participants were further screened for
eligibility via telephone. Eligibility criteria included persons aged 18 to
60 years and having a BMI of 25 to 36 kg/m2. Participants were
ineligible if they had a history of myocardial infarction, stroke, or cancer
in the last 5 years; diabetes, angina, or orthopedic or joint problems that
would prohibit exercise; major psychiatric diseases; and current, planned,
or previous pregnancy within 6 months. All participants agreed not to seek
additional weight loss treatment for 1 year. The screening also included the
Physical Activity Readiness Questionnaire (PAR-Q).16
Eleven participants endorsed 1 or more items on the PAR-Q and were required
to obtain physician consent to participate.
Following initial screening, participants were randomly assigned to
1 of 2 treatment groups: Internet education (education; n = 45) or Internet
behavior therapy (behavior therapy; n = 46). All participants were seen at
baseline, 3 and 6 months for objective weight and waist measurements and were
paid $10 and $25 for attending the 3- and 6-month follow-up appointments,
respectively. This study was conducted from April to December 1999 and was
approved by the institutional review board of the Miriam Hospital in Rhode
All participants attended an initial introductory group weight loss
session led by a doctoral-level clinical psychologist. At this meeting, baseline
measurements and written informed consent were obtained. In addition, participants
were taught Web site login procedures for this study. To ensure that all participants
had a sufficient level of computer and Internet knowledge, the basics of navigation
and login procedures were demonstrated on a computer. A detailed written guide
outlining login procedures and Internet navigation was also given to each
participant. To protect confidentiality, participants were given a login identification
code and weight data were transmitted and stored using this code rather than
participant names; however, they were advised that the potential existed for
data and e-mail messages to be intercepted and read.
The study Web site was accessible on the organization's Intranet and
provided a brief review of basic information related to weight loss and an
organized directory of selected Internet resources about diet, exercise, self-monitoring,
and other resources that included behavioral topics including social support,
stimulus control, and managing stress. During the introductory group session,
participants received a 1 hour lesson on behavioral weight control. At this
session, a standard calorie restriction diet of 1200 to 1500 kcals per day
and daily fat intake of less than 20% of calories consumed was recommended.
Participants were also instructed to increase gradually their physical activity
to burn a minimum of 1000 kcals per week. The importance of self-monitoring
was stressed and participants in both groups were encouraged to use the self-monitoring
Web resources to keep track of their diet and exercise daily. However, only
the behavior therapy group was asked to submit self-monitoring diaries to
the therapist each week. All participants were contacted at 3 months and 6
months to schedule individual appointments for follow-up measurements and
a brief 15 minute check-in with the clinical psychologist.
Behavior therapy participants received all of the above plus the following
procedures. They were instructed to report self-monitoring information each
week via an electronic diary accessible on the study Web site. Weekly self-monitoring
information included weight, calories, fat grams, and exercise energy expenditure.
Along with submitting their diaries, participants were also able to submit
any comments or questions they had to the therapist.
An e-mail message was sent to behavior therapy participants each week
during the 24-week program including a behavioral weight loss lesson and feedback.
The behavioral lesson included structured guidance about a variety of weight
loss topics on nutrition, exercise, or behavioral self-regulatory strategies.
In addition, each weekly e-mail included individualized feedback sent personally
from the doctoral-level therapist. The feedback included recommendations and
reinforcement based on progress noted in the self-monitoring diary and specifically
addressed weight loss progress, dietary intake, and energy expenditure. Recommendations
and strategies for improvement also were provided. In addition, the therapist
answered any questions raised by participants and provided general support
and encouragement via the e-mail message. Participants who did not send in
a log were sent a personal e-mail inquiring about their progress and were
encouraged to monitor and continue with the program. Participants in the behavior
therapy group also had access to an electronic bulletin board to facilitate
social support among participants assigned to this intervention.
The primary dependent measure was change in body weight. Weight was
measured in the clinic at baseline, 3, and 6 months in light street clothing,
without shoes, and on a calibrated scale. Height was measured using a wall-mounted
stadiometer. The circumference at the waist (measured at the umbilicus) was
measured with a Gulick steel tape measure using the procedure recommended
by Lohman et al.17 Physical activity was measured
at each assessment using a self-report format of the Paffenbarger activity
questionnaire.18 Dietary intake was measured
using the Block Food Frequency Questionnaire19
at baseline, 3, and 6 months and was analyzed using the National Cancer Institute
Dietary Analysis System 4.01 software program. Depressive symptoms were measured
using the Centers for Epidemiological Studies Depression Scale.20
Use of the Web site was tracked using a unique login identification code for
each participant to record each login. An index of participants' previous
experience with the Internet or e-mail was created by summing the number of
months participants had used e-mail plus the number of months they had used
Using an α level of .05 and power of 80%, a sample size of 37
for each group was needed to detect a 2.27-kg difference between groups. Assuming
an average attrition rate of 20%,21 a sample
of at least 90 subjects was selected. To detect changes in the outcomes of
weight, waist circumference, calorie intake, and expenditure, repeated-measures
analysis of variance (ANOVA) models were used. All analyses were performed
using the Statistical Package for the Social Sciences (SPSS for Windows version
10.05 SPSS Inc, Chicago, Ill).
A preliminary analysis showed that there were no differences between
groups for baseline measures of age, weight, BMI, waist circumference, or
Internet experience (Table 1).
Attrition was 15% and 22% at 3 and 6 months, respectively, and did not vary
by treatment group at either assessment (3 mo, χ2 = 0.288, P = .59; 6 mo, χ2 = 0.003, P = .96) (Figure 1). Participants
who did not attend the 6-month follow-up were significantly younger (t = −2.75, P<.007) and
had less e-mail or Internet experience at baseline but did not differ from
attendees on baseline BMI, education, or level of depressive symptoms.
Analyses were conducted for the 65 participants with objective follow-up
data at all 3 assessments (33 behavior therapy, 32 education). Repeated-measures
ANOVA examining weight showed a significant treatment × time interaction
(P = .005) (Figure
2). Those in the behavior therapy group lost more weight than those
in the education group from baseline to 3 months. Both groups maintained their
weight loss between 3 and 6 months but did not lose additional weight. Among
these participants who completed all 3 assessments, the behavior therapy group
lost mean (SD) 4.0 (2.8) kg by 3 months and 4.1 (4.5) kg by 6 months. Weight
loss in the education group was 1.7 (2.7) kg at 3 months and 1.6 (3.3) kg
by 6 months. Post hoc t tests showed that mean weight
losses were significantly different between the groups at both 3 (t = 3.4; P = .001) and 6 months (t = 2.1; P = .04). In addition, 45% of participants
in the behavior therapy group lost greater than or equal to 5% of initial
body weight compared with 22% of those in the education group (χ2 = 4.03; P = .05).
Similarly, repeated-measures ANOVA examining changes in waist circumference
between 0, 3, and 6 months showed a significant treatment × time interaction
(P = .005). Among those with all follow-up data,
the mean (SD) waist circumference reduction in the behavior therapy group
was 6.7 (4.7) cm at 3 months and 6.4 (5.5) cm by 6 months. In the education
group, the mean (SD) waist circumference reduction was 3.0 (4.0) cm at 3 months
and 3.1 (4.4) cm by 6 months. Post hoc t tests showed
mean (SD) waist reductions were significantly different between the groups
at both 3 months (P = .001) and 6 months (P = .009).
An intention-to-treat analysis was performed examining the pattern of
weight change from baseline to 3 and 6 months, including all randomized participants
using baseline weight for anyone with missing data at any follow-up period.
Repeated-measures ANOVA on the pattern of weight loss showed a significant
treatment × time interaction (P<.001). In
the intent-to-treat analysis, the education group lost a mean (SD) of 1.0
(2.4) kg at 3 months and 1.3 (3.0) kg by 6 months. Weight loss in the behavior
therapy group was 3.2 (2.9) kg by 3 months and 2.9 (4.4) kg by 6 months. Post
hoc t tests showed mean weight losses were significantly
different between the groups at both 3 months (P<.001)
and 6 months (P = .04). Within the intent-to-treat
sample, χ2 tests were used to compare the proportion of participants
in each group who lost at least 5% of initial body weight by 6 months. More
participants in the behavior therapy group than in the education group achieved
the 5% weight loss goal (35% vs 18%; χ2 = 3.39; P = .07).
Similarly, a repeated-measures ANOVA examining changes in waist circumference
between 0, 3, and 6 months using the baseline waist measurement for those
with missing follow-up data showed a significant treatment × time interaction
(P = .004). The mean (SD) waist reduction in the
education group was 2.1 (3.9) cm at 3 months and 2.3 (3.9) cm by 6 months.
In the behavior therapy group, mean (SD) waist reduction was 5.3 (4.9) and
4.6 (5.5), respectively. Post hoc t tests showed
that mean waist reductions were significantly different between the groups
at both 3 months (P = .001) and 6 months (P = .02).
To obtain an objective measure of Web site use, login data for all participants
were tracked over the 24-week period. Participants in the behavior therapy
group logged in to the Web site a mean (SD) of 19 (10.9) times over the first
3 months compared with 8.5 (10.4) for those in the education group (P<.001). Between months 3 and 6, logins decreased for
both groups (P<.001); however, participants in
behavior therapy group still logged in more often during this period—a
mean (SD) of 6.8 (6.2) times compared with 1.0 (3.0) times among education
participants (P<.001). Login frequency was significantly
correlated with weight change between 0 and 6 months both in the behavior
therapy (rs = −0.43; P = .003) and in the education group (rs = −0.33, P = .03).
Changes in dietary intake (kcal/d) at 0, 3, and 6 months were examined
using repeated-measures ANOVA for those with dietary data at all 3 assessments
(n = 62). There was a significant time effect (P<.001)
but no treatment × time interaction (P = .88),
indicating that both groups changed over time (Table 2). The change in dietary intake between baseline and 3 months
was marginally associated with weight loss during the same period in the behavior
therapy group (rs = 0.28, P = .10) but not in the education group (rs = 0.02, P = .93). Between months 3 and 6
the correlation between dietary change and weight change was similar in both
groups but only reached significance in the education group (behavior therapy, rs = 0.30; P = .10
vs education, rs = 0.38; P = .04).
Changes in physical activity between 0, 3, and 6 months were examined
using repeated-measures ANOVA for those with activity data at all 3 assessments
(n = 60). There was a significant time effect (P
= .03) but no treatment × time interaction. The change in physical activity
between baseline and 3 months was associated with weight loss during the same
period in the behavior therapy group (rs
= −0.32, P = .05) but not in the education
group (rs = −0.05, P = .79).
The behavior therapy group was asked to send in a self-monitoring diary
each week. Participants submitted a mean (SD) 13.65 (6.4) of self-monitoring
diaries during the 24-week program. Participants submitted more diaries during
the first 3 months than in the latter 3 months (8.5 [3.6] vs 4.6 [4.4]). Diary
submissions represented 46% of the total number of logins. Total number of
diaries submitted was significantly correlated with weight loss (rs = −0.50, P = .001). Only
28% ever posted a note to the bulletin board with a range of 1 to 7 postings
per person over the 6 months.
This study showed that participants who received a more structured Internet
behavior therapy intervention, including weekly e-mail contact, lost significantly
more weight and showed greater reductions in waist circumference at 3 and
6 months than those who received access to numerous weight loss Web sites.
Moreover, the behavior therapy program was effective in almost doubling the
percentage of participants who achieved a 5% weight loss goal. Weight loss
treatment goals of between 5% and 10% of initial body weight have been recommended
based on substantial evidence that many obesity-related conditions are improved
with weight losses of this magnitude.22-24
The pattern of weight losses in this program were essentially the same
for both groups and suggest that the weight losses occurred in the first 3
months. Encouragingly, participants maintained their weight losses, on average,
rather than showing regain during months 3 and 6. This maintenance was observed
despite decreased login frequency from months 3 through 6 in both groups and
diary submissions in the behavior therapy group. Both logins and diary submissions
were related to weight loss suggesting that if adherence to the program could
be improved and extended beyond 3 months, weight losses might also continue.
Attrition is also a substantial problem in many minimal-contact intervention25,26 studies and work-site programs. In
our study, attrition was 15% at 3 months and 22% at 6 months and did not vary
by treatment group. These rates are lower than several other minimal-contact
interventions and considerably lower than that reported for other work-site
weight loss programs.27,28 The
differences between the behavior therapy and education groups were statistically
significant when those participants who attended all assessments were examined
and when an intent-to-treat analysis was used.
Weight losses achieved in the behavior therapy group are better than
losses achieved with other minimal interventions5,29,30
and are comparable with those achieved in recent evaluation of a structured
commercial program.31 Although our study did
not include a face-to-face program as a comparison group, weight losses in
this study were not as good as are seen in the research literature on standard
behavioral weight loss programs. Such programs involving weekly face-to-face
contact typically produce 9.1-kg weight losses in 20 to 24 weeks. As noted
above, procedures to promote sustained use of the Web resources and continued
diary submission might improve weight losses; however, the advantage of Internet
weight loss programs may be in increasing the audience and the reach of treatment
programs. These types of programs might not produce weight losses that rival
Participants in both the behavior-therapy and education groups reported
changes in diet and exercise behaviors of similar magnitude despite significantly
different weight losses. Other studies with significant between-group differences
in weight loss have also failed to find differences on self-reported dietary
and exercise measures.32,33 Despite
the lack of difference detected by the measures used in this study, the only
explanation for differences in changes in body weight and waist circumference
is differential changes in either 1 or both of these behaviors.34
The inability to detect differences in eating and exercise between the groups
may reflect difficulty of accurately measuring these behaviors. It is also
probable that participants in the behavior therapy group became more accurate
in their estimation of dietary intake and exercise because they were self-monitoring
intake and activity; hence, there was a greater association between behavior
changes and weight change in this group.
The major strength of our study is that it was a randomized trial with
objective weight and waist measurements and was the first study to examine
using Internet technology to deliver a structured behavioral weight loss program.
The primary limitation of our study is that these results are for initial
weight loss. The efficacy of a program such as this for producing longer-term
weight losses and maintenance remains to be demonstrated. Further studies
with larger samples including equal numbers of men and women are needed to
replicate these findings. Furthermore, as this study was an initial feasibility
and efficacy trial, the design does not allow for dismantling of the behavior
therapy program to determine the critical components of this intervention.
Certainly, continued contact has been a critical element of weight loss programs
and other behavior-change programs. The difference in contact between conditions
may be responsible for the differences in weight loss. Future studies could
examine the effects of different types of contact on weight loss using the
Internet and e-mail. Finally, it should be noted that participants in behavior
therapy group had met face-to-face with the therapist that they had been corresponding
with weekly by e-mail. Other Internet programs using exclusively e-mail or
online communications without an initial face-to-face meeting may produce
In summary, the results of this study showed that a treatment program
that included access to Internet weight loss resources, structured behavioral
components, weekly contact, and individualized therapist feedback, delivered
via e-mail, produced better initial weight losses compared with providing
access to Internet weight loss resources alone. Thus, the Internet appears
to be a viable method for delivery of structured behavioral weight loss programs
deserving of future research.