Regulation of Energy Balance and Metabolism - Mechanisms Behind and Beyond Obesity and Weight Loss

Study Overview
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Brief Summary
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The study aims to investigate homeostatic and hedonic mechanisms regulating appetite, energy balance and metabolism in obesity and the effects of three distinct obesity treatments on these regulatory mechanisms.

Detailed Description
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Obesity is widely acknowledged health problem affecting millions of people globally. Enormous efforts have been made to solve the problem, but long-term results of the conventional weight loss and/or weight management strategies have been poor indicating still inadequate understanding of the problem. Surgical, rather than weight-centred lifestyle interventions, have proved to be the most effective tool available to treat obesity within individuals suitable for obesity surgery. Current surgical interventions are, however, suitable only for a small subset of obese individuals. In general, there is a need for development of new approaches and therapies that are safer and more individualized to each patient in the struggle against obesity and related disorders. To achieve these goals, research must focus to investigate and understand the complex homeostatic and hedonic regulation of eating behavior and energy balance in different physiological and pathological conditions. This study aims to investigate homeostatic and hedonic mechanisms regulating energy balance and metabolism in obesity and the effects of three distinct obesity treatments on these regulatory mechanisms. The regulatory mechanisms are investigated at the level of metabolism, autonomic and central nervous systems as well as subjective, both implicit and explicit, experiences. A total of 90 obese female volunteers (18-65 years, body mass index > 35 kg/m2), of which 30 females waiting for bariatric surgery (SURG), 30 females attending a dietary treatment program for obesity (DIET) and 30 females attending Health at Every Size (HAES) program, will participate in the study. The obesity treatment for SURG and DIET groups follows the principles of the Current Care Guidelines for Obesity (adults) and the treatment for the HAES group applies the strategies of the non-diet wellness-based HAES program. The treatment programs of the DIET and HAES groups include 8-10 weekly group sessions organized by authorised nutritionist. The study includes also two four-hour visits at the research laboratory of the Institute of Public Health and Clinical Nutrition, University of Eastern Finland, the first visit organized before the participants attend any of the obesity treatments and the second visit 12 months later. During the laboratory visits psychophysiological signals (EEG, ANS, facial EMG and eye tracking) are monitored and blood samples taken throughout the experimental period. Participants will also perform two computer-based test sessions, the first one at baseline and the second before a snack meal. Two meals (breakfast and snack meal) are offered to the participants during the experiment in order to study the regulatory mechanisms of interest both at the homeostatic and hedonic states.

Official Title
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Regulation of Energy Balance and Metabolism - Mechanisms Behind and Beyond Obesity and Weight Loss

Conditions
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Obesity, Appetitive Behavior

Intervention / Treatment
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* Procedure: SURG
* Behavioral: DIET
* Behavioral: HAES


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: body mass index >34 kg/m2 native finnish speaker right-handed Exclusion Criteria: pregnancy or breast feeding severe visual impairments, severe scalp skin lesions or intracranial bleeding during previous six months severe neurological, psychiatric or cardiovascular disease type 1 or 2 diabetes mellitus use of weight loss medications or other treatments known to affect weight heavy alcohol use any other condition (medical or other) the principal investigator considers as an obstacle to participation

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: SURG<br>subjects attending bariatric surgery | Procedure: SURG<br>* bariatric surgery according to Finnish Current Care Guidelines for Obesity in adults<br>|
| Active Comparator: DIET<br>subjects attending dietary weight loss program | Behavioral: DIET<br>* dietary weight loss program according to Finnish Current Care Guidelines for Obesity in adults<br>|
| Active Comparator: HAES<br>subjects attending Health At Every Size weight management program | Behavioral: HAES<br>* treatment is based on the previously published procedure (e.g. Bacon et al. 2002) and Health At Every Size trademark, consisting of body acceptance, eating behaviour, physical activity, nutrition, and social support<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Implicit associations | D-score of Implicit Association Test | Change from baseline D-score at 1 year | 
| Explicit ratings | Ratings on visual analogue scales for wanting and liking of presented foods | Change from baseline visual analogue scale at 1 year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Event-related potentials | Event-related potentials measured by EEG | Change from baseline event-related potentials at 1 year | 
| Glucose | Plasma glucose, fasting, postprandial | Change from baseline glucose at 1 year | 
| Insulin | plasma insulin, fasting, postprandial | Change from baseline insulin at 1 year | 
| Ghrelin | plasma ghrelin, fasting, postprandial | Change from baseline ghrelin at 1 year | 
| Leptin | serum leptin, fasting | Change from baseline leptin at 1 year | 
| Peptide YY | plasma peptide YY, fasting, postprandial | Change from baseline PYY at 1 year | 
| Endocannabinoids | plasma endocannabinoids, fasting, postprandial | Change from baseline endocannabinoids at 1 year | 
| Weight | body weight, fasting | Change from baseline weight at 1 year | 
| Eating behaviour | self-reported questionnaires | Change from baseline eating behaviour at 1 year | 
| Psychosocial characteristics | self-reported questionnaires | Change from baseline psychosocial characteristics at 1 year | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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obesity, appetite, food reward, hormonal responses, psychophysiological responses, implicit measures, explicit measures