Scientists reviewed all existing studies on the subject and performed the first "prospective" study

Jul 6, 2006 10:44 GMT  ·  By

A team of researchers asked whether the fat really are jollier, as popular opinion often claims. But, in spite of the chubby image of Santa Claus and other jolly characters, what they found was that obesity does not protect people from mental health problems, on the contrary. Are the Fat Jollier? "The answer," they write, "is a most emphatic 'No.'"

Looking at eight different indicators of mental health problems, the researchers examined whether the stereotype of the "jolly fat" is accurate. It's not, says researcher Robert E. Roberts, Ph.D., of the University of Texas Health Science Center at Houston. "There was either no observed association between obesity and psychological dysfunction or the obese were worse off," he and his colleagues write. "In no case did we observe better mental health among the obese. In sum, the obese were not more jolly."

Roberts and his colleagues looked at data from a long-term study of residents of Alameda County, Calif., gleaning information for 1,739 people who were at least 50 years old in 1994 and who provided information on body mass index and mental health. They used data from that year as well as 1999, when participants were questioned again.

Measures of mental health included questions about overall happiness, life and relationship satisfaction, positive or negative mental state, feeling loved, depression and optimism. The researchers also looked at respondents' social support, level of financial strain, number of recent stress-inducing life events, chronic medical conditions and frequency of exercise.

Limited previous research exists on the issue of whether obese people have fewer or more mental health problems than the general public; Roberts and his colleagues reference 16 such studies. They found that in seven of those studies, obesity had a negative effect on mental health; in six, there was a positive association between obesity and mental health; and in three, no association was recorded.

Roberts notes that this study differs from most existing research in that it provides "prospective" data, meaning the researchers were able to look at respondents' information in 1994 and how that information had changed by 1999.

They suggest further research on a variety of issues, including whether there is a link between obesity and anxiety and how nutrition (including consumption of carbohydrates - linked both to depression and weight levels) affects mental state.

"Data are also needed," Roberts and his colleagues say, "on the natural history of obesity and mental health to ascertain the nature and magnitude of reciprocal effects and the implication of such effects for prevention and treatment."

By this, Roberts says, they mean "whether psychiatric problems such as depression increase the risk of becoming obese and, in turn, whether becoming obese increases the risk of becoming depressed."

Photo: Jolly Trixie