132 Obesity
TABLE 6. 5Effects of Strategies Designed to Improve Long-Term Outcome
Bene“cial Ef fect Observed
Bene“cial Ef fect Bene“cial Ef fect
6 to 12 Months after 13 or More Months after
Strategy Initial Treatment Initial Treatment
Very-low calorie diets Yes No
Continued therapy
Extended therapy (continued weekly or
biweekly group sessions up to one year) Yes Yes
Therapist contact by mail phone Yes Unknown
Telephone prompts by nontherapists No Unknown
Skills training
Relapse prevention training during
initial treatment No Unlikely
Relapse prevention training combined
with posttreatment therapist contacts Yes Unknown
Portion-controlled meals
Provision of portion-controlled meals Yes No
Optional purchase of portion-controlled meals No Unlikely
Financial incentives
Financial incentives for weight loss No No
Financial incentives for exercise No No
Physical activity
Supervised exercise No No
Use of personal trainers No No
Home-based exercise Yes Unknown
Short-bout exercise home exercise equipment Yes Unknown
Social support training
Peer support training No Unlikely
Social support training for clients recruited
with friends or relatives Yes Unknown
Multicomponent programs
Therapist contact increased exercise Yes Yes
Therapist contact social support Yes Yes
Therapist contact increased exercise social support Yes Yes
Source:Data from Perri (2002).Extended Treatment
Improving the long-term effects of treatment involves “nding
ways to assist clients in sustaining key changes in the behav-
iors that regulate energy balance and weight loss. Extending
the length of treatment may offer the opportunity for contin-
ued reinforcement of adherence to the behaviors needed for
negative energy balance. Perri, Nezu, Patti, and McCann
(1989) tested whether extending treatment would improve
adherence and weight loss by comparing a standard 20-week
program with an extended 40-week program. The results
showed that the extended program signi“cantly improved
outcome compared to the standard treatment. During the pe-
riod from Week 20 to Week 40, participants in extended treat-
ment increased their weight losses by 35% while those in the
standard length treatment gained a small amount of weight.
Moreover, both weight loss and adherence data supported the
hypothesis that the longer patients are in treatment the longer
they adhere to the behaviors necessary for weight loss.
Perri and Corsica (2002) reviewed the results of 13 stud-
ies in which behavioral treatment was extended beyond six
months through the use of weekly or biweekly treatment
sessions. On average, treatment in the extended-intervention
groups in these 13 studies included 41 sessions over the
course of 54 weeks. One year after the initiation of treat-
ment, those groups that received behavior therapy with
extended contact succeeded in maintaining 96.3% of their
initial losses. The inclusion of a control group (i.e., behav-
ioral treatment without extended contact) in three of the
studies permits a rough comparison of the groups with and
without extended treatment (see Figure 6.2). The groups
without extended contact maintained about two-thirds
(66.5%) of their initial weight reductions. Judging the ef-
fects of the extended-treatments by comparison with the