About a couple weeks ago, you might have heard about a study out of the University of Hawaii that found overweight and obese women (BMI>25) had 'more sex' than normal-weighted ones. The study was all over the news because it challenged what we would generally believe - after all, 'skinny' women are hotter, so they should have more sex.
The study surveyed over 7,000 women aged 15-44 about their sexual habits, and a higher percentage of the larger women reported having had sex. The researchers admitted they were surprised. "These results were unexpected and we don't really know why this is the case," said lead researcher Dr Bliss Kaneshiro. The big question remained - why?
Well, perhaps they should have talked to researchers over at University of Alabama about their new study. While looking to see if the weight of obese women might be tied to their overall ability to control impulses, they found an interesting result. Overweight women are simply more impulsive - even in methods completely unrelated to food.
In a study of 95 men and women, the researchers looked at "delay discounting" - a measure of the degree to which an individual is driven by immediate gratification vs. the prospect of larger, but delayed, rewards. The participants were given the choice of receiving varying hypothetical amounts of money immediately or fixed hypothetical amounts of money to be received after delays of two weeks to ten years. The obese women undervalued the delayed rewards at a rate three-to-four times greater than that of normal weight women - meaning they're a lot more impulsive.
If you bring together the two parts, it seems obvious why overweight and obese women would have more sex. Because of a lack of impulse control, the hefty ladies are more likely to say 'yes' to a man's advances.
That's not to say that all fat women are sluts - don't get me wrong. While the University of Hawaii study found that overweight women are more likely to have had sex, they also found that the sexual behavior between the two groups was essentially the same. That is, BMI was not significantly associated with sexual orientation, age at first intercourse, frequency of heterosexual intercourse, and the number of lifetime or current male partners. So one group was no more slutty or prudish than the other. The only difference is that more overweight women had had sex at all - a small variance in the big scheme of sexual behavior.
Small enough that, perhaps, their increased impulsivity could be at fault. Which just might give those University of Hawaii researchers their answer. Of course, they have yet to show if this difference is genetic versus learned - which might open up a whole other can of worms.