In a study to examine the impact of desired body
weight on the number of unhealthy days subjects report
over one month, researchers at Columbia University Mailman
School of Public Health found that the desire to weigh
less was a more accurate predictor of physically and mentally
unhealthy days, than body
mass index (BMI). In addition, the desire to lose
weight was more predictive of unhealthy days among Whites
than among African-Americans or Hispanics, and among women
than among men.
After controlling for actual BMI
and age, the researchers found that men who wished to
lose 1 percent, 10 percent, and 20 percent of their body
weight, respectively, reported 0.1, 0.9 and 2.7 more unhealthy
days per month than those who were happy with their weight.
Among women, the corresponding increase in numbers of
reported unhealthy days was 0.1, 1.6 and 4.3. Persons
who were happy with their weight experienced fewer physically
unhealthy days (3.0 vs 3.7) and mentally unhealthy days
(2.6 vs 3.6) compared with persons unhappy with their
weight.
"Our data suggest that some of the obesity epidemic
may be partially attributable to social constructs that
surround ideal body types," said Peter Muennig, MD,
MPH, Mailman School of Public Health assistant professor
of Health Policy and Management. "Younger persons,
Whites, and women are disproportionately affected by negative
body image concerns, and these groups unduly suffer from
BMI-associated morbidity and mortality."
Approximately 66% of the more than 150,000 U.S. adults
studied wanted to lose weight, and about 26% were satisfied
with their current weight. With respect to BMI, 41% of
normal weight people, 20% of overweight people, and 5%
of obese people were happy with their weight. Older persons
were also more likely to feel positively about their weight
than were younger persons. However, in all models, perceived
difference was a stronger predictor than was BMI of mentally
and physically unhealthy days.
The researchers emphasize that there is a large body
of evidence suggesting that social stress adversely affects
mental health as well as physical health. "Our findings
confirmed that there was a positive relationship between
a person's actual weight and his or her desired weight
and health, be it physical or mental," observed Dr.
Muennig.
Obesity
is one of the greatest public health threats. Over 7 million
quality-adjusted life years are lost annually as a result
of excess body weight in the United States alone. There
is evidence that discrimination against heavy people is
pervasive, occurring in social settings, the workplace,
and the home. These processes are likely internalized,
leading to a negative body image that also may serve as
a source of chronic stress.
"The data add support to our hypothesis that the
psychological stress that accompanies a negative body
image explains some of the morbidity commonly associated
with being obese. Our finding that the desire to lose
weight was a much stronger predictor of unhealthy days
than was BMI further suggests that perceived difference
plays a greater role in generating disease," said
Dr. Muennig.
The paper, "I Think Therefore I Am: Perceived Ideal
Weight as a Determinant of Health," will be published
in the March issue of the American Journal of Public Health.
