Toward a More Effective Treatment of Obesity: A RCT on Emotional Eating Reduction by Dialectical Behaviour Therapy

Over half of the Dutch adult population has a Body Mass Index of 25 kg/m2 or
higher (overweight or obesity) and in 14%
obesity occurs (CBO, 2008). Present interventions, aimed at changes in life
style, fail to result in long-lasting weight loss (Mann
et al., 2007). The same holds true for behavioural treatments (Wilson, 1994),
though they are associated with less short-term
relapse (Werrij et al., 2009). There are important reasons to assume that
weight reduction treatment can be substantially
improved by paying systematic attention to emotional eating as a core
characteristic of (a high proportion of) obesity. Emotional
eating is eating in response to negative emotional states and as much as 40% of
the obese show significant degrees of
emotional eating (Van Strien, in press). The efficacy of the adapted version of
DBT for eating disorders was shown in two case reports, one uncontrolled trial
and two RCT*s. These last two studies however used waiting list conditions as
control conditions (Chen, et al., 2008), no comparison was made with CBT. There
has thus not been any direct comparison between DBT and CBT. The effectiveness
of this DBT (in a Dutch translation) for reduction of body weight and emotional
eating in the Netherlands was recently shown in a case-control study at GGZ
Oost-Brabant (Roosen, 2008). Of course, as is well-known, the limitation of
such a study is the risk on selection bias and confounding. These limitations
of the scarce studies available together with the promising nature of DBT for
treatment improvement of obesity led us to propose the present study.

We will examine whether the delivery of Dialectical Behaviour Therapy to obese
patient
with high levels of emotional eating compared to that of the treatment as
usual, Cognitive Behavioural Therapy, is preferable in
terms of effectiveness.

DBT is expected to result in larger decreases in BMI, emotional eating and
binge eating and in larger increases in quality of life compared to CBT.
Moreover we expect that these changes will persist.
Finally, secondary beneficial psychological effects are expected, specifically
reduction of levels of anxiety, depression and impulsivity and improvement of
skills regarding coping with emotions.

This study assesses the effectiveness of DBT in comparison to the effectiveness
of the treatment as usual, the (standard) cognitive behavioural therapy, by
using a randomised controlled design situated in the eating disorder and
obesity unit of Amarum.

Based on this objective several sub-questions are relevant, such as:
1a) What are the (extra) effects (measured in BMI, and quality of life) of DBT
compared to CBT?
1b) What are the (extra) effects of DBT compared to CBT in the long run?

DBT is expected to result in larger decreases in BMI, emotional eating and
binge eating and in larger increases in quality of life compared to CBT.
Moreover we expect that these changes will persist.
Finally, secondary beneficial psychological effects are expected, specifically
reduction of levels of anxiety, depression and impulsivity and improvement of
skills regarding coping with emotions.

Participants will be allocated at random to either of the two treatment
conditions:
- Emotion regulation skills training based on the Stanford Dialectical
Behaviour Therapy protocol for binge eating disorder
(DBT), without a diet advice or stimulation of physical exercise. This is a
systematic skills training, aimed at improving
identification of feelings, mindfulness, tolerance of distress, and skills to
regulation of emotions. The treatment consists of 20
sessions 2 hour group therapy and is given by two expert therapists.
- The Cognitive Behavioural Therapy (CBT) is based on the cognitive model of
eating disorders. The program focuses on
normalizing eating behavior, (i.e. realizing a regular eating pattern and
stopping bingeing), raising body awareness, and
optimizing physical movement by psycho-education, self-monitoring,
self-control, cognitive restructuring as well as psychomotor
therapy. It does not aim at improvement of emotion regulation skills. The
treatment consists of 20 days of group therapy, and is
given by a cognitive-behavioural therapist, a sociotherapist and a psychomotor
therapist.

Treatments will be given by different therapists. The therapists will be self
selected at Amarum (under supervision of Mirjam
Lammers). Maries Roosen of the GGZ Oost-Brabant will train the therapist for
the DBT. She has extensive experience with the
very detailed DBT protocol and has been the principal therapists of the
case-control (calorie restricted diet by dietician) for
treatment of obese people with high degrees of emotional eating (Roosen, 2008).

Data-collection and random assignment to DBT or CBT takes place at Amarum by
Mirjam Lammers. Data-entry and analysis of the data takes place at Radboud
University Nijmegen.

Measurements take place before treatment (T1), after treatment (T2) and at four
follow-up measurements (T3 at * year, T4 at
1 year, T5 at 2 years and T6 at 4 years after treatment).

One group receives 20 sessions of grouptherapy (2 hours/week, DBT).
The other group receives 20 sessions of grouptherapy (1 day/week, CBT).

Not applicable.