When some men see women in bikinis or lingerie - they lose their ability to delay gratification: whether it's about food or money.
The research in the Journal of Consumer Research is called "Bikinis Instigate Generalized Impatience in Intertemporal Choice".
From the the lead author: "Prior exposure to sexy stimuli may influence the choice between chocolate cake or fruit for dessert."
It's all about the inability to delay gratification.
"The study demonstrates that bikinis cause a shift in time preference: Men live in the here and now when they glance at pictures featuring women in lingerie. That is, men will choose the immediately available rewards and seek immediate gratification after sex cue exposure." (src)
Yet another clue into how easily manipulated we can be by various forms of advertising... and how seriously pathetic we men can be at times!
The ability to delay gratification is another key to successful weight management.
References: See the full study here (PDF).