London: Are you impulsive or an extrovert? Well, these are some of your personality traits which may help determine what your weight will be as you get older, according to a 50-year study.

In the study, researchers from America's national Institute on Ageing looked at detailed statistics from 1,988 people to determine how personality traits are associated with weight and body mass index.

They concluded that while weight tends to increase with age, impulsivity was the strongest predictor of who would be overweight, the 'Sunday Express' reported.

Conversely, they found that people who displayed the most conscientiousness in their daily lives were those who tended to be leaner and did not put on weight.

Dr Angelina Sutin, who led the study, said: "While on the face of it this sounds simple, to maintain a healthy weight it is necessary to have a healthy diet but also to have a sustained programme of physical activity and this requires a great deal of commitment and restraint.

"Such control appears to be very difficult, indeed often impossible, for highly impulsive individuals. Impulsive people are more likely to overeat and binge-drink, where someone more conscientious will compensate for any days they eat too much by having less the next day. Someone impulsive can't do this even with the best intentions.

"One biscuit is never enough, they have to keep going until they are all gone. Someone more controlled and conscientious will be able to have just one small piece of cake, enjoy it and leave it there. We found that, more often than not, impulsive people cannot do this."

The researchers also found that greater weight gain occurred in those who enjoy taking risks in all areas of their lives; career, love life and financial decision making.

"Those who are antagonistic to others, always looking for a fight or an argument, also put on more weight as they got older. Those who were cynical had the worst results in terms
of weight gain and competitive people too tended to fall into the fatter category.

"The control that keeps us on an even keel in terms of mood might have something to do with overeating and not taking a measured view of food. High neuroticism, where someone is constantly worried and feels they are being persecuted, also seems to make them eat more and make bad judgment calls on what they eat," Dr Sutin said.

In fact, the study found that those who rated most highly on impulsivity measures weighed 22 pounds more, on average, than those who were the least impulsive.

The study, which used results from a wider research project into ageing and its effects among people of Baltimore, began in 1958, with participants and doctors recording all
aspects of getting older from normal ageing and everyday life, cardiovascular ageing, cognitive ageing as well as what happens to emotions as people grow older.

"To the best of our knowledge we are the first to examine whether personality is associated with fluctuations in weight over time," the researchers wrote in their report published by
the American Psychological Association.