Using implementation intentions to change unhealthy eating habits in a clinical morbid obese sample.

Approximately 12% of the Dutch population is obese and 1-2% suffers from morbid obesity, and these numbers are increasing rapidly. (Morbid) obesity is associated with various serious diseases including type 2 diabetes mellitus, cardiovascular diseases, several forms of cancer, as well as a reduced life expectancy and a poorer quality of life. A radical yet highly effective treatment is bariatric surgery. To prepare people who will undergo bariatric surgery, patients are required to participate in a psychological treatment program. This program focuses on important factors to establish health behavior change in anticipation of and after the surgery. Although such programs concentrate on important factors like knowledge and motivation, usually, they do not facilitate the development of new automatic healthy behaviors. In order to reduce unhealthy and initiating healthy behaviors as well as to establish behavior change maintenance, promoting new desirable habits is essential. This can be established with the use of implementation intentions. Implementation intentions are specific if-then plans that aid the development of new, healthy, habits. Implementation intention are very applicable to many psychological treatment programs, are cost-effective, easy to implement, and have been found to be very effective. Yet, implementation intentions have hardly been used in samples such as morbid obese patients in a clinical setting. The present study aims to examine whether unhealthy eating habits as well as unhealthy snack consumption can be diminished with the use of an implementation intention intervention.

It is hypothesized that patients receiving the implementation intention intervention will (1) develop stronger healthy eating habits and (2) consume fewer unhealthy snacks compared to patients in a control condition.

T0: Baseline

T1: Directly after the intervention

T2: One week after the intervention

T3: Six months after the intervention

T4: One year after the intervention

T5: Two years after the intervention

The intervention is aimed at changing unhealthy snacking habits and consists of two parts:

1. First, participants will monitor their unhealthy snacking behavior for seven days using a cue-monitoring diary. In this diary, participants report which unhealthy snacks they consume as well as the situation in which this behavior was performed and their most important trigger for unhealthy snacking.

2. After this week, participants will receive elaborate instructions to formulate an implementation intention. For this 'if-then' plan, participants identify their most important trigger for unhealthy snacking (the 'if'-part of the plan; based on the cue-monitoring diary) and specify an alternative desirable behavior to perform in their snacking situation (the 'then'-part). They then formulate the complete if-then plan. This plan will reduce their old habit, while simultaneously create a new mental association between the situation that was formerly inducing the unwanted habit, with a new, healthier response.