Factors Associated With Obesity in Adult Women: Respiratory Exchange Ratio, Heart Rate Variation and Body Image

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.