They say the way to a man's heart is through his stomach - but a well-fed woman may also be easier to woo, new research suggests.
Scientists found that women with full stomachs were more responsive to romantic cues than those feeling empty.
After eating, their brain circuits reacted more strongly to images of loving couples holding hands or embracing.
Neutral images, such as a bowling ball, a stapler, or a tree, did not have the same effect.
Lead researcher Dr Alice Ely, from the University of California at San Diego, US, said: "We found that young women both with and without a history of dieting had greater brain activation in response to romantic pictures in reward-related neural regions after having eaten than when hungry ...
"T hey were more responsive when fed. This data suggests that eating may prime or sensitise young women to rewards beyond food. It also supports a shared neurocircuitry for food and sex."
The findings, published in the online journal Appetite, appear to challenge other research showing that people are typically more sensitive to rewarding stimuli when hungry. But in those studies the kinds of stimuli investigated included food, money and drugs rather than romantic cues.
A previous study conducted by the same team found that "highly palatable" food rewards such as chocolate cake produced a greater brain response from women with a history of dieting after they had eaten.
The new research showed that, when stimulated by romantic images, one brain region of dieters with a full stomach showed a different pattern of activity than that of non-dieters.
"The pattern of response was similar to historical dieter's activation when viewing highly palatable food cues, and is consistent with research showing overlapping brain-based responses to sex, drugs and food," said Dr Ely.
Magnetic Resonance Imaging (MRI) was used to scan the brains of the study participants.
To make the women feel fed, they were given a a chocolate-flavoured meal-replacement shake.