In these days, obesity and depression are two major problems in the society, especially among children and adolescents. The correlation between obesity and mental diseases is significant, but not obvious, but what is obvious is that obesity and depression are associated with many health complications – hypertension, coronary heart disease, etc. (Faith MS, et al., 2002) Many studies have been conducted to investigate the influence of obesity on depression and vice versa. Some studies have also suggested that an adolescent obesity is a strong predictor of adulthood obesity and it is associated with depression, especially in women and young girls. (Luppino, et al., 2010).
By World Health Organization is obesity defined as an excessive fat accumulation. Obesity occurs when the caloric intake is higher than the caloric output, this leads to the accumulation of fat tissues. To calculate obesity or overweight, we use the body mass index. The body mass index, also BMI, is a number using as an indicator of underweight, overweight and obesity. If adults have BMI from twenty-five to thirty, it is regarded as an overweight, if BMI is greater than thirty or equal thirty, it means that the person is obese. BMI varies with age and gender (Klish WJ, 2012)
Obesity makes people more likely to have conditions including heart disease and stroke, high blood pressure, diabetes, osteoarthritis, etc. But not everyone who is obese has these problems, some of these problems can be hereditary (Janssen I., et al., 2005)
Overweight and obesity in childhood have an important impact on physical and physiological health. Young people become obese or overweight because they do not have enough physical activity or if they have bad eating habits. Genetics also participate in a child´s weight status. If you want to prevent obesity you have to change eating habits, have more physical activity and better lifestyle – avoid alcohol and smoking (Ogden CL, et al., 2010).
Depression is a serious condition that affects your physical and especially mental health. Depression can affect thoughts, behaviour and feelings of a person. Many physical problems are connected to depression for example, problems with sleeping (insomnia or hypersomnia) and problems with appetite. Also, depressed mood, anhedonia, fatigue, and thoughts of death are depression criteria. Depressed adolescents may be moody, pessimistic, bored or sad. Even children may be depressed and have social problems, especially among peers (American Psychiatric Association, 2000).
Successfully treating of depression can be a lot of easier than successfully treating obesity if treatment of depression starts in the beginning. Recommendation of many doctors for people with some depressive symptoms is that they should not be afraid and go to visit doctors and start with the treating. Treatment includes medicaments or psychotherapy with the specialist (Bonin L., 2012).
III. Moderator and mediator variables
Gender, age, ethnicity and socioeconomic status, in other words, moderators affect the relationship between obesity and depression. There are gender differences between men and women – obese women are more inclined to be depressed than obese men. Also, there is a difference between races, for example, white females tend to see themselves as obese or overweight when clinically they are not, this leads to low self-esteem and bad weight management. Basically, it is important to recognize moderators such as gender or age to recognize those obese adolescents which might have tendencies to be depressed (Nemiary, D., et al., 2012).
Mediators determine how and why moderators such as age, gender, ethnicity, etc. influent causal effect of obesity onto depression. For example, body dissatisfaction can be a mediator for the association between obesity and bullying. Studies found that obese adolescents are at an increased risk for depression because of peer victimization. Peer victimization is enmity toward children by other children in none family relationship. (Nemiary, D., et al., 2012). A study by Janssen et al. found that obesity is related to peer victimization among younger youth (Janssen, et al., 2005). Also, another meta-analysis done between years 1978 and 1977 brought results, where the scientists confirmed the relationship between peer victimization and depression. (Hawker, D. and Boulton M., 2000). Thus, obesity may lead to peer victimization and this may lead to depression among young people – for example, when someone is bullied, that person is more inclinable to be depressed.
Dissatisfaction with your own body can be a reliable predictor of depression. Obesity in adolescents may lead to teasing, which may cause depression among obese youth, who have greater body dissatisfaction (Nemiary, D., et al., 2012). A one study found that body mass index, depression and lower self-esteem are the most common factors linked to body dissatisfaction especially among women and college students (Franklin, J., et al., 2006). A very recent cross-sectional study showed that in a survey of almost one thousand and five hundred youth in grades seven through twelve, obese youth has higher body dissatisfaction and greater depressive symptoms, including anhedonia which means a lacking interest in activities they used to enjoy (Barefoot, J., et al., 1998).