While researchers have been interested in finding links between personality and health issues (luckily there’s no relationship between personality and cancer), the results have been sparse. But a new study finds that certain personality traits – like impulsivity, for instance – do appear to be connected to the odds of gaining more weight over the years.

Weight gain is a good candidate for a health issue with a potential link to personality, because much of overweight and obesity is due to a particular behavior: overeating, which is thought to be a method of emotion regulation for overeaters.

Being aware of people’s personality traits may help doctors and public health officials determine who’s at risk for weight gain over the years. It may also help determine what "interventions" will work best for each individual.

The researchers in the new study looked a number of personality traits in almost 2,000 participants who took part in a national study on aging. They tracked personality along with the participants’ weight fluctuations over a period of 50 years, which is an impressively long period for a research study.

The personality traits included those widely viewed by psychologists as the major bases of personality and called the "big five": Openness, Conscientiousness, Extraversion, Agreeableness and Neuroticism. Each of these categories has subcategories, making a total of 30 personality traits.

The researchers only found a few connections between personality and weight. The strongest was between impulsivity (a subcategory of Neuroticism), where people who ranked in the top 10% of impulsivity weighed about 22 pounds more than people in the lowest 10%. People who ranked low in self-discipline (a subcategory of Conscientiousness) also tended to gain more weight over the study’s span.

The authors point out that to stay at a healthy weight, it is necessary to stick to a healthy diet, resist temptation, and take part in regular physical activity. People who are impulsive and/or lack self-discipline may have trouble with both of these aspects.

Past studies have found that people who are high in Neuroticism and low in Conscientiousness are also more likely to smoke, binge eat and drink alcohol, and use drugs. Therefore, it is particularly interesting that weight gain was lined to the same personality traits in the current study, especially in light of the fact that more and more research is showing that food activates the same brain areas as other, more "classical" additions.

Being aware of people’s personality traits may help doctors and public health officials determine who’s at risk for weight gain over the years. It may also help determine what "interventions" will work best for each individual. For example, people with high impulsivity and low Consciousness may respond best to weight loss routines that focus on meal planning and schedules. Other personality traits may benefit from focusing on exercise routine planning. With obesity reaching frightening proportions, we seem to need all the tools we can in the fight against it.

The study was carried out by researchers at the National Institute on Aging and NIH. It was published in the July 11, 2011 online issue of the Journal of Personality and Social Psychology.