In studies of the general population, early studies showed few consistent patterns with
respect to psychosocial distress and obesity, partly due to small samples and varying
assessment tools. The relationship between BMI, smoking status, and depressive
symptoms was studied in a large US national sample, using validated instruments.
The investigators found that the relationship between obesity and depression varied
by sex. Among women, but not men, greater BMI was weakly associated with elevated
reports of depressive symptoms. This relationship remained significant after
controlling for age, years of education, and smoking status, indicating that relative
body weight is weakly related to psychological distress among women but not men. Another US study sought to test the relationships between relative body weight
and clinical depression, suicidal thoughts and suicide attempts in an adult US general
population sample comprising over 40,000 people. Outcome measures were past year
major depression, suicidal thoughts and suicide attempts. Among women, increased
BMI was associated with both major depression and suicide ideation. Among men,
lower BMI was associated with major depression, suicide attempts and suicidal
thoughts. There were no racial differences. Studies of clinical populations have used psychometric instruments for assessment of mental health and psychological functioning in obese individuals and compared them with healthy reference populations. In a much-cited Swedish study ,
severely obese men and women reported distinctly poorer current health and less
positive mood states than the reference subjects, a situation that was worse in women
than in men. Anxiety and/or depression on a level indicating psychiatric morbidity
were more often seen in the obese, again more often in women. The obese subjects
rated their mental well-being worse than chronically ill or injured patients, for example
patients with rheumatoid arthritis, cancer survivors with no recurrence and
spinal-cord injured persons several years after injury. These symptoms improved
with subsequent weight loss from bariatric surgical treatment, providing further support
for the idea that obesity was driving the psychological impairment. In contrast to the widely accepted view that much of the observed psychopathology
associated with obesity is secondary to the obesity itself, one line of research suggests
that psychosocial stress induces central obesity and the metabolic syndrome. Originally suggested by Björntorp and colleagues, subsequent research has been
hampered by largely cross-sectional designs and lack of prospective data. However, a
recent study found that the effect of job strain on subsequent weight change was
dependent on baseline BMI in men but not in women . In the leanest quintile
(BMI 22) at baseline, high job strain and low job control were associated with
weight loss, whereas among those in the highest BMI quintile ( 27), these stress
indicators were associated with subsequent weight gain. No corresponding interaction
between baseline BMI and weight change was seen among women. Furthermore,
the metabolic syndrome, with abdominal obesity as an important determinant, was
recently demonstrated to be closely related to cumulative exposure to work stressors
over 14 years, independent of other relevant risk factors. Employees with chronic
work stress (three or more exposures) were more than twice as likely to have the syndrome
compared to those without work stress. Altered adrenocortical function
induced by stress might influence hepatic lipoprotein metabolism and insulin sensitivity
at target organs, providing a partial explanation for the social inequalities in
obesity and obesity-related disorders. However, given the recent development with
decreasing socioeconomic differences in obesity seen in the US this is obviously a
complex issue.
Other than the conventional view of obesity as a condition carrying both medical
and psychosocial disabilities to the individual, obesity may also been viewed as a sociological
problem deriving from current cultural norms of beauty, normality and socially
acceptable behaviour. In other cultural contexts, where food was less plentiful, obesity
was often considered beautiful. On the other hand, a negative attitude towards obesity,
with stigmatisation of obese individuals, is not entirely a recent phenomenon, with
ascetism and self-denial idealised in many Western societies throughout the centuries.
One of the views driving the stigma of obesity is the notion that it is self-inflicted, with
the cardinal sins of sloth and gluttony emanating from low morals and poor character.
Despite increasing knowledge about the importance of heritability in obesity, and the
societal changes behind the obesity epidemic, these attitudes still prevail.
The growing stigma attached to all degrees of overweight reflects a society with a
contemporary ideal of extreme leanness. There is a belief that this attitude is setting
the stage for an epidemic of dieting and eating disorders.
One of the repeating themes emerging from research on psychosocial aspects of
obesity is the necessity for a gender perspective. Medically, due to the greater likelihood
of central adiposity in men, obesity may be said to confer a greater risk among
males. However, there is much evidence suggesting that the psychological and social
consequences of obesity are far worse for women. Even so, it should be noted that
increased prevalence of body dissatisfaction is occurring in both men and women.
Is there an association between obesity and depression? In Western society, being
overweight has been associated with increased risk for low self-esteem and depression.
It has, however, not been quite clear whether obesity increases the risk of
depression, or if depression increases the risk of obesity, or if there is a reciprocal relation
such that the obese are at increased risk of depression and the depressed are at
increased risk of obesity. Roberts et al. summarised 11 studies studying this association
using cross-sectional or prevalence study designs, with seven of these finding
some evidence of greater risk of depression among the obese. But while seven of these
studies found support for the proposition that the obese are at a greater risk for
depression, evidence was not uniformly robust, and the temporal relation between
obesity and depression was unclear. In their own study of 2,123 adults age 50 and
older, participants reported their height, weight and depressive symptoms during
interviews in 1994 and 1999. Subjects who were obese in 1994 had twice the risk of
becoming depressed in 1999 than subjects who were not obese in 1994. They did not
find any support for depression predicting subsequent obesity, after adjusting for
baseline obesity, or limiting the analyses to the non-obese at baseline. Accordingly, to
date, there is little conclusive evidence that obesity is caused by depression, whereas
obese people do seem more prone to develop future depression.
