Regulation of Energy Balance and Metabolism - Mechanisms Behind and Beyond Obesity and Weight Loss
Condition: Obesity; Appetitive Behavior
MeSH terms: Obesity; Weight Loss
Study type: Interventional

Summary: 
      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: 
      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.
    

Intervention name(s): SURG; DIET; HAES
Intervention type(s): Procedure; Behavioral; Behavioral
Intervention description(s): bariatric surgery according to Finnish Current Care Guidelines for Obesity in adults; dietary weight loss program according to Finnish Current Care Guidelines for Obesity in adults; 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
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Basic Science
Keywords: obesity; appetite; food reward; hormonal responses; psychophysiological responses; implicit measures; explicit measures