Multidimensional influencing factors of eating disorders and obesity: social consciousness, family environment and biological mechanisms

II. Eating Disorders Eating disorders (ED) are a group of syndromes characterized by abnormal eating behaviors and psychological disturbances, accompanied by significant weight changes and/or physiological dysfunctions. Eating disorders are associated with cognitive, emotional, and behavioral disturbances. Patients often exhibit low self-esteem, low self-evaluation, perfectionism, depression, anxiety, and other abnormal personality traits. When patients feel rejected, they experience low self-esteem and adopt inappropriate coping mechanisms. The perfectionism of patients with eating disorders leads them to view their weight and body shape as flaws, resulting in abnormal eating habits to achieve a perfect physique. Patients with eating disorders have very low self-evaluation, which is entirely dependent on their evaluation of their own body; furthermore, these patients also have varying degrees of body image disorder, experiencing perceptual impairment and distorted cognition of their own image. These erroneous cognitions cause patients to spend a significant amount of time each day obsessively thinking about food, weight, and body shape, leading to abnormal eating behaviors. Related studies have found that overweight children aged 6-13 often exhibit dieting and/or binge eating behaviors, and 20%-37% of obese adolescents experience eating disorder-related symptoms such as bulimia, low self-esteem, depression, and anxiety. This early-life overweight status may be a significant contributing factor to the later development of eating disorders. Generally, adolescence is the peak period for the onset of eating disorders, with girls being more prone to them than boys. Eating disorders are mainly classified into anorexia nervosa, bulimia nervosa, and atypical eating disorders. Anorexia nervosa is characterized by significant weight loss due to voluntary refusal to eat, accompanied by body image disturbances, significant behavioral deviations, and mental and psychological disturbances. Anorexia nervosa often causes severe malnutrition, metabolic and endocrine disorders, and may also present with intermittent episodes of polyphagia. Anorexia nervosa is generally less common in obese patients. Bulimia nervosa refers to recurrent episodes of binge eating behavior, accompanied by a strong preoccupation with controlling weight. Binge eating episodes are the main characteristic of bulimia nervosa. Patients relieve the inner tension caused by the urge to eat through binge eating, but afterwards feel regret, guilt, and even depression. To counteract the weight gain caused by binge eating, they often use methods such as induced vomiting, laxatives, or excessive exercise to lose weight. Unlike anorexia nervosa, patients with bulimia nervosa experience greater weight fluctuations. Atypical eating disorders refer to abnormal eating behaviors that do not fully reach the state of bulimia nervosa or anorexia nervosa. Compared to anorexia nervosa and bulimia nervosa, atypical eating disorders are milder, but the proportion of individuals in this state is alarming. Individuals with atypical eating disorders are at risk of developing bulimia nervosa/anorexia nervosa. III. Factors Influencing Various Psychological and Behavioral Problems in Obese Patients The causes of psychological and behavioral problems in obese patients are multifaceted. Currently understood influencing factors include social ideology, family environment, lifestyle, biological factors, and dietary structure.

Social Ideology: For nearly half a century, the mainstream aesthetic in society has been "thinness as beauty," and obesity has often been criticized. Under the influence of various media, the pursuit of slimness has become a popular fashion, while obesity is associated with negative evaluations such as "laziness," "gluttony," and "ugliness." Although the aesthetic of "thinness as beauty" has positive significance in promoting public health, the public's pursuit of the perfect figure generally exhibits a kind of blindness, being overly critical of obese individuals and lacking understanding and care. In this environment, obese individuals, on the one hand, find it difficult to accept themselves due to the influence of social aesthetics, and on the other hand, may suffer discrimination, ridicule, and isolation from those around them, which can eventually lead to various psychological and behavioral problems.

Family environment: The family environment is one of the leading factors in the development of various psychological problems. The personality traits, values, and communication styles among family members all have a subtle influence on obese individuals. Families of obese patients often share some common characteristics: a hostile atmosphere, a lack of effective communication, excessive criticism of the obese individual, and frequent neglect of the obese individual's emotional needs. The lack of emotional support within the family can further impair normal social relationships for obese individuals.

Lifestyle: With the development of technology and the improvement of economic levels, modern work and lifestyles have undergone tremendous changes. Advanced internet media, convenient transportation, and convenient living facilities have led people to tend to be sedentary in their work and daily lives, lacking physical exercise. Furthermore, people are more inclined to communicate online, lacking face-to-face social interaction. Obese individuals' lack of exercise and normal social activities further contribute to the development of various psychological problems.

Biological factors: ① Decreased expression of adipokines: Decreased expression of relevant adipokines in obese patients is associated with the occurrence of depression. Leptin plays a role in regulating body weight and energy metabolism, and also has antidepressant functions. Animal studies have found that increased adiponectin levels in the brain can alleviate depressive-like behaviors in experimental animals. Compared with normal individuals, obese patients typically have lower levels of leptin and adiponectin, and exhibit varying degrees of leptin resistance and insulin resistance. ② Low-inflammatory state: Obese patients all exhibit a chronic low-inflammatory state. Inflammation is an important pathophysiological mechanism for neurological diseases such as depression, cognitive impairment, and dementia. TNF-α circulating in the peripheral circulation of obese patients can cross the blood-brain barrier, inducing cognitive impairment and depressive-like behaviors. ③ Changes in the structure and function of the nervous system: Related studies have found that the overall brain volume of obese patients is reduced, and gray matter atrophies. These changes in the structure and excitatory function of the nervous system may be the reason for sympathetic-parasympathetic dysregulation and depression in obese patients.

Dietary structure: There is a link between dietary structure and the occurrence of depression. Studies have shown that long-term consumption of foods rich in saturated and trans fatty acids is more likely to cause depressive symptoms. Long-term deficiency of n-3 polyunsaturated fatty acids can trigger hyperactivity of the hypothalamus-pituitary-adrenal (HPA) axis, disrupt the glucocorticoid receptor signaling pathway, and induce mood and behavioral changes, including depression.