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Long Term Effects of Obesity Treatment

Is early identification possible of who, over the long term, will have a failed result from obesity surgery and conservative weight loss treatment?

Photo illustration: Colourbox

About the project

In this study we wish to study psychosocial factors and attitude changes in patients who undergo an obesity operation compared with those who receive conservative weight loss treatment.

Obesity surgery is the most effective treatment method for patients with morbid obesity where conservative weight loss treatment doesn’t work.

The success of such operations is however not just dependent on a medically successful operation, but also on the patient changing their lifestyle after the procedure. By following the patients regularly before and after treatment over a 10 year period we will be able to chart the factors which are central for change of eating habits and physical activity, and thereby the level and maintenance of weight loss.

The results will form a foundation to develop preventative and monitoring measures in weight loss treatment.


The objective is early identification of those who after surgery/conservative weight loss treatment will get problems with weight regulation and mental health. By investigating different factors associated with the overweight before treatment, such as eating and exercise habits, life situation and mental health, we wish to discover in what degree these factors affect lifestyle changes and weight loss over a ten year period after treatment.

The main focus in the project is on obesity surgery. We partly wish to discover why some begin to gain weight again some years after surgery and what the health and psycho-social effect of obesity surgery is over the long term. It is especially important to find out if it is possible to prevent problems with changes of eating and exercise habits after obesity surgery.

All patients who seek obesity surgery at the Senter for Sykelig Overvekt (Centre for Morbid Obesity), Oslo University Hospital, Aker and who seek conservative weight loss treatment at Tonsåsen Rehabilitation Centre are asked for consent to participate in the project. Participants answer a questionnaire once before and four times after treatment. The data collection started in January 2011.


Obesity is an increasing problem both in Norway and internationally. Obesity surgery and conservative weight loss treatment in a systematic way are both relatively new as established treatments in Norway and we therefore know little about how things progress with these patient groups over a long time perspective.

Most obesity surgery patients manage to change their habits, but a significant proportion of around 10-30% of patients experience post-operative problems in changing their eating behavior and their lifestyle. Weight reduction stops too soon, and they begin to gain weight again or they develop new eating problems, something which leads to both negative medical and psychological effects. This is especially concerning since obesity surgery is an extensive and irreversible procedure.


Patients who received obesity surgery in 2005 at Aker University Hospital participated in a retrospective study where they answered a questionnaire about their experiences four years after the procedure. Fifteen of these patients also participated in an in depth interview. The results from this study are under publication.


The project is internally financed through contributions from minor research funds at the Department of Psychology, University in Oslo.


The project is a large cooperation project between several research milieus.

Oslo University Hospital, Aker and the Department of Psychology,UiO are responsible for the survey.

Partner institutions are Tonsåsen Rehabilitering, The University of Tromsø, The Norwegian Institute of Public Health, Uppsala University and the University of Bergen.

Published Nov. 5, 2012 2:02 PM - Last modified May 7, 2014 4:29 PM