This study is a randomized clinical trial comparing state-of-the-art, standard behavior
therapy for weight loss (SBT) with a maintenance tailored treatment (MTT) with varied
behavioral prescriptions, goals, and formats over time. The overall hypothesis in the study
is that the two treatment approaches will show different patterns of weight loss over time,
and in particular that the MTT approach would be associated with better long-term
maintenance of weight loss.
Recent dramatic increases in prevalence have made obesity the number one nutritional problem
in the US. Of particular concern is the fact that, although available treatments are
effective in producing clinically significant weight loss, their ability to sustain weight
loss long term is poor. This study is based on a conceptual analysis of this problem that
argues for greater attention to two issues related to the temporal dynamics of the challenge
of long-term weight control. These are: 1) the environment is continually changing and is
not supportive of weight control and 2) the intervention methods that are effective in
inducing short-term changes in behaviors and weight often lose their potency over time
because of habituation.
This study is a randomized trial in which obese men and women are assigned to one of two
study conditions, Standard Behavior Treatment (SBT) or Maintenance-Tailored Treatment (MTT).
The MTT has adaptation to change as its central theme. A primary technique that is used to
convey this theme that is different than traditional behavior treatment is that participants
are asked to deliberately change weight-loss strategies systematically over time rather than
to use the same approach consistently across time. Frequent change serves as a platform for
teaching a larger variety of weight-control skills and thus strengthening study participants
ability to adapt their weight-control strategies to changing circumstances. Changing
weight-control strategies regularly also helps to reduce the extent to which habituation to
strategies implemented invariantly over time diminish the salience of behavioral cues and
the potency of behavioral reinforcers for sustaining weight-control efforts over time.
Individuals in both treatment groups receive active intervention for a period of 18 months,
followed by 12 months of no-treatment follow-up.
The primary hypothesis tested is that MTT will produce larger mean weight losses at 30-month
follow-up than SBT. Moreover, it is predicted that the better long-term success of the MTT
group will be due primarily to better weight-loss success beyond 6 months, the point at
which most people begin to regain weight with standard therapy.
- Participants must be 18 years of age or older
- Body mass index between 30.0 and 37.0
- serious current physical disease (e.g., heart disease, cancer, and diabetes) for
which physician supervision of diet and exercise would be needed.
- initial fasting glucose values above 120 mg/dl
- resting blood pressure at or above 90 DBP or 150 SBP will be strongly encouraged to
see their primary care physician for further evaluation and will not be accepted into
the study unless they do so and have physician consent for participation.
- physical problems that preclude their participation in the diet and exercise
components of the program
- currently taking weight-loss medications
- currently participating in another formal weight loss-program
- currently pregnant or plan to become pregnant during the next 30 months
- currently receiving treatment for a major psychological disorder or have scores on
the Beck Depression Inventory above 27.0, indicative of likely clinical depression.
- only one individual per household accepted into the study