Obesity
Conditions
Keywords
diet, bariatric surgery, appetite
Brief summary
The biggest challenge in obesity management is maintaining weight loss in the long-term. Currently, bariatric surgery is the most effective treatment, leading to sustained weight loss that is not yet achievable with lifestyle intervention (e.g. diet). The reasons behind its success is still not clearly understood, but beneficial changes in the homeostatic and hedonic appetite systems (the two major physiological regulators of appetite), along with the microbiome (known to have a mediatory effect on appetite) have been shown to occur after bariatric surgery. These alterations are in opposition to what is seen after diet-induced weight loss. Today, the component of appetite regulation that drives bariatric surgeys' long-term success is still unknown. By comparing a lifestyle and surgical intervention in parallel, the investigators can observe the impact of a similar magnitude of weight loss on these three domains of appetite regulation simultaneously, thereby illuminating the mechanisms behind bariatric surgerys' success.
Interventions
DIETARY_SUPPLEMENTVLED group
10-week weight loss period with total meal replacement, consisting of 750 kcal/day. Measurements will be taken at baseline (before diet start), 10 weeks after intervention start (Wk11), and at 1 year.
PROCEDURESleeve Gastrectomy group
Standard clinical practice with 2-week diet consisting of 750 kcal/day prior to surgery. The pre- and post-surgical diet of this group will be matched with the VLED group in macro- and micronutrient composition. Measurements will be taken at baseline (before diet start), 10 weeks after intervention start (Wk11), and 1 year after surgery (sleeve gastrectomy)
PROCEDUREGastric Bypass group
Standard clinical practice with 2-week diet consisting of 750 kcal/day prior to surgery. The pre- and post-surgical diet of this group will be matched with the VLED group in macro- and micronutrient composition. Measurements will be taken at baseline (before diet start), 10 weeks after intervention start (Wk11), and 1 year after surgery (gastric bypass)
Sponsors
St. Olavs Hospital
Namsos Hospital
University of Copenhagen
University of Leeds
Norwegian University of Life Sciences
Norwegian University of Science and Technology
Study design
Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
No
Inclusion criteria
* scheduled for bariatric surgery * patient in obesity clinic * Body mass index (BMI) 35-55
Exclusion criteria
* Currently taking medication known to affect energy metabolism or appetite * Current cancer diagnosis * Substance abuse * Enrolled in another obesity treatment * Eating disorders * pre-existing endocrine disorders (e.g. diabetes) will not be excluded, but final analysis will controlled for these conditions
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Postprandial blood plasma concentration of Glucagon-like peptide-1 (GLP-1, satiety hormone) | Week 11 | Blood samples will be collected at fasting, and then every 30 minutes after a standardized test meal up to 150 minutes. A radioimmunoassay method will be used to measure the concentration of total GLP-1. This method measures antigen concentrations by the use of antibodies. |
Countries
Norway
Outcome results
None listed