Hostile men may pack on more pounds over time than their less hostile, more laid-back peers, new research shows.

The more hostile a man's personality, the more his body mass index (BMI) increased over the following two decades, Dr. Hermann Nabi of Hopital Paul Brousse in Villejuif, France and his colleagues found. BMI is the ratio of height to weight, used to determine if someone is within a normal weight range or is underweight, overweight or obese.

The researchers looked at data on 6,484 men and women participating in a UK study of socioeconomic status and health. Study participants ranged in age from 35 to 55 at the study's outset. They completed a standard scale measuring hostility at the beginning of the study, while their BMI was determined at four points over 19 years.

At the beginning of the study, the researchers found, both men and women with higher hostility levels also had higher BMIs. BMIs rose over time.

While the relationship between BMI and hostility remained constant for women, hostility seemed to accelerate weight gain over time in the men.

Hostility could affect BMI in many ways, Nabi and his colleagues note in a report of the study appearing in the American Journal of Epidemiology. For example, hostile people may be less likely to follow health guidelines on diet and exercise, or be more likely to be depressed.

Prior studies have linked hostility to heart disease, high blood pressure, and a greater overall mortality risk, the researchers also note.