The face can reveal whether our weight has changed, but how much is required for others to see it?
Dr Nicholas Rule, co-author of a new study on the subject, explains:
“Women and men of average height need to gain or lose about three and a half and four kilograms, or about eight and nine pounds, respectively, for anyone to see it in their face, but they need to lose about twice as much for anyone to find them more attractive.”
Fat in the face, or ‘facial adiposity’, is a good indicator of someone’s body weight, but it’s also more than that, said Dr Rule:
“It is a robust indicator of one’s health.
Increased facial adiposity is associated with a compromised immune system, poor cardiovascular function, frequent respiratory infections, and mortality.
So, even a small decrease can improve one’s health.”
The researchers used a series of pictures digitally altered to increase or decrease the person’s weight.
Participants then looked at randomly selected pairs of images and were asked to choose the heavier one.
It turned out that a change in BMI of 1.33 kg/m2 is required for someone to notice.
Daniel Re, the study’s co-author, explained:
“We calculated the weight change thresholds in terms of BMI rather than simple kilograms or pounds, so that people of all weights and heights can apply it to themselves according to their individual stature.”
The researchers then went on to look at how much change in weight was required before someone looked more attractive.
For women the difference was 6.3kg or about 14 pounds.
For men it was 8.2kg or around 18 pounds.
Even taking into account men’s greater average weight, women needed to lose proportionally less weight to appear attractive, Dr Rule said:
“The difference between the groups suggests women’s facial attractiveness may be more sensitive to changes in weight.
This just means women attempting to lose weight need to shed slightly fewer pounds than men for people to find them more attractive.”
Dr Re added:
“When it comes to incentives for weight loss, some people are more motivated to look attractive than to improve their health.”
The study was published in the journal Social Psychological and Personality Science (Re & Rule, 2015).
Pretty face image from Shutterstock