People with personality traits of high neuroticism and low conscientiousness are likely to go through cycles of gaining and losing weight throughout their lives, according to an examination of 50 years of data in a study published by the American Psychological Association.

Impulsivity was the strongest predictor of who would be overweight, researchers found.

Study participants who scored in the top 10 percent on impulsivity weighed an average of 22 lbs, more than those in the bottom 10 percent, according to the study.

The researchers, from the National Institute on Aging, looked at data from a longitudinal study of 1,988 people to determine how personality traits are associated with weight and body mass index. Their conclusions were published online in the APA’s Journal of Personality and Social Psychology.

Participants were drawn from the Baltimore Longitudinal Study of Aging, an ongoing multidisciplinary study of normal aging administered by the National Institute on Aging. Subjects were generally healthy and highly educated, with an average of 16.53 years of education. All were assessed on what’s known as the “Big Five” personality traits -- openness, conscientiousness, extraversion, agreeableness and neuroticism -- as well as on 30 subcategories of these personality traits. Subjects were weighed and measured over time.

Although weight tends to increase gradually as people age, the researchers, led by Angelina R. Sutin, PhD, found greater weight gain among impulsive people; those who enjoy taking risks; and those who are antagonistic -- especially those who are cynical, competitive and aggressive.

“Previous research has found that impulsive individuals are prone to binge eating and alcohol consumption,” Sutin said. “These behavioral patterns may contribute to weight gain over time.”

Among their other findings: Conscientious participants tended to be leaner and weight did not contribute to changes in personality across adulthood.

“The pathway from personality traits to weight gain is complex and probably includes physiological mechanisms, in addition to behavioral ones,” Sutin said. “We hope that by more clearly identifying the association between personality and obesity, more tailored treatments will be developed. For example, lifestyle and exercise interventions that are done in a group setting may be more effective for extroverts than for introverts.”

(From news reports)