St Andrews University study claims stressed men prefer heavier women
Higher levels of stress may result in men finding heavier women more physically attractive, according to University of St Andrews research.
The study compared men undergoing intensive army cadet training with men whose environment remained unchanged.
During training, men appeared to show a preference for heavier-looking women.
Lead researcher Dr Carlota Batres said men's preferences may adapt in tough environments so they mate with women best equipped to survive and reproduce.
"Our findings provide new evidence for the malleability of preferences depending on the environment," she said.
"We found that the weight preferences in prospective female partners changed in response to the harsher environment and then remained at the new level while the environment remained harsh.
"Such changes in preferences may be beneficial because they allow for increased opportunities to form partnerships with those who are better equipped to survive illness or uncertain food availability."
Participants were asked to rate computer-generated female faces, which varied in apparent weight.
For the control subjects - whose lives and environment did not change compared to baseline - there were no changes in their preferences.
The army cadets' preference increased towards heavier-looking women when they started training, and plateaued until their training finished.
Cadets reported higher levels of stress, physical strain, mental pressure, pain and being more out of their comfort zone.
Prof David Perrett, who runs the Perception Lab at the university, said previous studies had found that populations living in places where life is tough prefer heavier women.
"No-one has shown that as the environment changes, people's preferences change too," he said.
"So it appears that when the going gets tough, tougher-looking women become more attractive."
The study involved 23 men in the cadet sample and nine men in the baseline sample.
Researchers also tested women's responses to men's faces (eight in the cadets and 11 in the baseline), but found no differences whether or not they were taking part in cadet training.
Dr Batres said: "This may be because the sample was too small, or it may be because weight is more important in men's preferences because weight can affect reproductive health."
The university said the research, published by journal Ethology, was the first to suggest that people's face preferences change when their environment changes.