Investigation of the Effects of Obesity Surgery on Appetitive Behaviour
Status:
Unknown status
Trial end date:
2018-06-01
Target enrollment:
Participant gender:
Summary
Among all the existing ways to treat obesity (lifestyle, pharmacological), Roux-en-Y gastric
bypass (RYGB) surgery is currently the most effective. It results in long term weight loss
maintenance, significant remission of obesity-related comorbidities and decreased overall
mortality. It also induces changes in gastrointestinal hormones responses, with an increase
of anorexigenic hormones GLP-1, and PYY.
Although successful, the mechanisms for RYGB-induced weight loss are not completely
understood. The RYGB does result in increased satiation, decreased calorie intake and
decreased preferences for sweet and fatty foods. Previous work from our lab has shown using
progressive ratio task (PRT) that RYGB specifically decreases the appetitive behaviour for
sweet and fat stimuli but not for vegetables. The reasons for this change in appetitive
behaviour after the surgery remain unknown. They may be triggered by changes in gut hormones,
conditioned taste aversion (negative post-ingestive effects) or changes in serum bile acids
levels.
This study aims to assess whether RGYB-induced gut hormone changes contribute to the decrease
in appetitive behaviour for sweet and fatty foods observed after the surgery.
This is a double blind controlled study comparing the effect of blocking gut hormones with
somatostatin analogue (octreotide) on the appetitive behaviour for sweet-fat candies will be
carried out. Appetitive behaviour will be measured using the progressive ratio task.
The investigators hypothesize that blocking the gut hormones in obese patients with RYGB will
increase their appetitive behaviour for sweet-fat candies.