Factors Associated With Obesity in Adult Women: Respiratory Exchange Ratio, Heart Rate Variation and Body Image
Condition: Obesity
MeSH terms: Obesity
Study type: Observational

Summary: 
      The prevalence of obesity all over the world has increased year by year, and how to
      effectively prevent and treat obesity has become an important health care issue. Many
      adjustable and nonadjustable causes of obesity have been proposed, such as unbalanced eating
      habits, lack of physical activity, psychological factors, and genes. The practice guidelines
      recommended lifestyle modification interventions which include diet control combined with
      regular exercise as the core treatment for obesity, but the effects on different ethnic
      groups are not ideal. In order to provide more choices for future weight loss intervention,
      it would be important to find out more risk factors for obesity. Previous studies have shown
      that lower sympathetic activity assessed by heart rate variability was related to obesity;
      obese men have higher respiratory exchange rates which might indicate they are more likely to
      use carbohydrates as a source of energy, and therefore, fat cannot be effectively consumed
      and led to an accumulation in the body. Furthermore, previous studies showed that Asians are
      less satisfied with their body image than other races, and women are more dissatisfied than
      men. Poor body image will lead to a series of effects, such as changes in eating habits,
      hormonal changes, depression, etc., eventually forming a vicious circle of obesity. However,
      most aforementioned Asians in these studies are immigrants living in overseas areas such as
      the Americas, and cannot fully represent the ethnic groups in Asia. Therefore, the purpose of
      this study are (1) to investigate the physiological and psychological factors influence
      obesity in adult women, including respiratory exchange rate, heart rate variability, and body
      image, and (2) to examine the correlations among these risk factors and different degree of
      obesity.
    

Detailed description: 
      Methods: This is a cross-sectional design study. Subjects were recruited from Taipei city.
      Inclusion criteria are women aged between 20 and 50 years old and have willing to participate
      to this study. Subjects will be excluded as follows: (1) taking medications that affect
      weight or hormones; (2) fluctuation of weight exceeds 2 kg within 3 months before the
      enrolled in study; (3) any condition that causes the subject fail to complete the test paper,
      such as: cognitive problems; (4) diagnosed with mental illness; (5) pregnancy or menopause.
      The assessments include: obesity-related indicators (height, weight, waist and hip
      circumference, percentage of body fat), respiratory exchange ratio, heart rate variability,
      body image (multi-directional self-body relationship questionnaire (MBSRQ), figure rating
      scale (FRS)), physical activity (Seven-days Physical Activity Recall, 7-d PAR), eating
      behavior (Three-Factor Eating Questionnaire, revised 18-item, TFEQ-18), and depression
      (Mongomery-Asberg Depression Rating Scale, MADRS). Statistical analysis will be performed by
      using SPSS version 18 (SPSS Inc, Chicago: SPSS Inc.), and significant level would be set at
      0.05. Analysis of variance (ANOVA) will be used to examine the differences of all measured
      variables among different degrees of obesity groups. In addition, we will use multiple linear
      regression analysis to examine whether overweight and obesity are significantly related to
      respiratory exchange rate, heart rate variability and body image.
    

Intervention name(s): Respiratory exchange ratio; Heart rate variability; Body composition; Eating behavior; Physical activity recall; Depression; Body image
Intervention type(s): Device; Device; Device; Behavioral; Behavioral; Behavioral; Behavioral
Intervention description(s): Ask participants to supine on bed, using a ventilator hood cover upon their head. Measure respiratory exchange ratio for 15 minutes.; Ask participants to supine on bed for 10 minutes, connect electrodes on their right wrist. Measure heart rate variability for 5 minutes.; Ask participants to supine on bed for 10 minutes, connect electrodes on their right wrist and right foot. Measure body composition.; Fill in questionnaire (Three-Factor Eating Questionnaire, revised 18-item, TFEQ-18).; Fill in questionnaire (Seven-days Physical Activity Recall, 7-d PAR).; Fill in questionnaire (Mongomery-Asberg Depression Rating Scale, MADRS).; Fill in questionnaire (multi-directional self-body relationship questionnaire (MBSRQ), figure rating scale (FRS)).
Observational model: Case-Control
Time perspective: Cross-Sectional
Sampling method: Probability Sample
Study population: 
        Asian, mainly living in Taiwan
      
Keywords: Respiratory exchange ratio; Body image; Heart rate variability