However, the study also found that between obese and normal-weight men, the impulsivity levels are nearly the same.
The researchers conducted the study to see how obese and normal-weight men and women differed in their decision-making skills, specifically in delay discounting, the measure of how much an individual is driven by immediate gratification versus the willingness to wait for delayed but greater rewards.
In the study of 95 men and women, the researchers gave the participants the choice of receiving varying hypothetical amounts of money immediately or fixed hypothetical amounts of money to be received after delays of two weeks, one month, six months or one, three, five or 10 years.
The hypothetical rewards ranged from 1,000 dollars to 50,000 dollars.
The researchers found that obese women discounted the value of future rewards at a rate three-to-four times greater than that of normal-weight women, suggesting greater impulsivity.
However, obese men and the male and female control subjects all showed similar levels of delay discounting.
The results were the same even when the researchers controlled for differences in IQ and income, both of which have been found to be related to measures of impulsivity.
UAB researcher Rosalyn Weller, Ph. D., the study's principle investigator, said that one explanation for the differences between men and women may be found in a personality trait known as eating-related disinhibition, which is the tendency to overeat in response to certain situations or cues such as a big display of dessert.
"Our study found that obese men have more impulse control than obese women. So, obese men may be protected from more impulsive behavior on the delay-discounting task by having lower disinhibition in general. Obese women may have the double whammy of being female and having higher body mass index," Weller said.
The study is published in the November issue of the journal Appetite.