by Carole Jackson, Bottom Line Health
When it comes to personality and weight control, there are certain things that make perfect sense. Those undisciplined types who mindlessly munch in front of the TV or purposefully stuff down food at the kitchen table tend to be heavier, while the organized, conscientious folks — the ones who measure out their portions, for example — are more likely to keep the pounds off. But apparently, not all personality-weight associations are quite so logical. Now scientists are learning that some surprising personality traits may lead to a growing waistline.
The National Institute on Aging (NIA) recently studied the relationship between personality and weight over a substantial period of adulthood. The findings reveal that people who are aggressive, cynical and competitive are prone to gaining extra weight. Now that had me scratching my head, I must admit. Arenât those competitive types going to be the ones most likely to do whatever is necessary to stay in control — of their weight and everything else?
To learn more about the findings, I called lead investigator Angelina Sutin, PhD, a postdoctoral fellow at the NIAâs Laboratory of Behavioral Neuroscience in Baltimore. She told me that the research, which appeared in the July issue of Journal of Personality and Social Psychology, produced a mix of results that donât always add up as easily as weâd expect.
“We know how complex the reasons for weight gain can be, and we were extremely interested to see how psychological factors might contribute,” Dr. Sutin said.
Dr. Sutin lead the observational study, which examined data from the NIAâs Baltimore Longitudinal Study of Aging (BLSA), an ongoing research project that addresses normal aging. In the BLSA, 2,000 men and women were weighed and their body mass index (BMI) and other markers for excess fat were measured over the course of 50 years. Participants were generally healthy and highly educated. All were evaluated on what personality psychologists call the “Big Five” domains of personality — extraversion, agreeableness, neuroticism, conscientiousness and openness — along with 30 subcategories of these traits. Researchers measured which personality traits were associated with weight gain — and which ones werenât.
Among all personality traits — and this was not unexpected — the biggest contributor toward weight gain was impulsiveness (a subcategory of neuroticism). Those who fell into the high end of the impulsivity range gained, on average, an extra 22 pounds over their life spans. “Individuals with this [characteristic] tend to give into temptation and lack the discipline to stay on track amid difficulties or frustration,” Dr. Sutin found. “To maintain a healthy weight, it is typically necessary to have a healthy diet and a sustained program of physical activity, both of which require commitment and restraint. Such control may be difficult for highly impulsive individuals.”
What other traits influenced an accumulation of pounds? Some others were obvious, like extraversion, which I can easily associate with a certain joie de vivre that could lead to weight gain. Neuroticism, conservativeness, warmth and a tendency to take risks were also traits that (unsurprisingly) were associated with weight gain. It isnât that hard to picture a heavyset, warm, conservative person — especially if he is also a risk taker — Winston Churchill, anyone? But then there are the antagonistic people (those who are aggressive, competitive and cynical). We might expect them to be thinner because, after all, no mere plate of food is going to get the best of them! But they actually tended to gain more and more weight over the decades, until they became clearly too heavy for good health. And there may be a physiological reason for that, Dr. Sutin told me. “Antagonistic people can be very reactive to stress,” she said, “and stress increases the production of hormones that can lead to weight gain.”
And who consistently maintained their weight over the decades? No surprise here. It tended to be the people who were open, agreeable, conscientious, active, straightforward, modest, orderly and/or dutiful.
More research may yield clues as to how to apply the personality traits of thinner people to those less likely to resist fried chicken and Oreos. Until then, if youâre having trouble watching your weight, watch your stress level. It may be turning your battle of the bulge into a war.
Source:
Angelina Sutin, PhD, a postdoctoral fellow, National Institute on Aging, Laboratory of Behavioral Neuroscience, Baltimore.