Well, researchers from the University of Toronto have calculated how much weight people need to lose before others notice or find them more attractive.
"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," said Nicholas Rule, associate professor of arts and science.
But wait, that's not all.
"They need to lose about twice as much for anyone to find them more attractive," Rule said.
The study wasn't as superficial and silly as it sounds. The amount of weight in the face is a very good gauge of a person's BMI (body mass index) and can give tip-offs about what's going on with your immune system, cardiovascular health and stress levels.
"It is a robust indicator of one's health," Rule said. "Increased facial adiposity [perception of weight in the face] 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."
To figure out at what point a change in perception of facial adiposity occurs, Rule and co-author of the study, Daniel Re, digitally created a collection of pictures of male and female faces between 20 and 40 years old. In all the photos, the subjects had neutral expressions, pulled back hair, and no facial adornments. The researchers changed each image to produce sequences of weights ranges on a gradually increasing scale.
Participants in the study were asked to compare randomly drawn pairs of faces from each sequence and choose the heavier-looking one. After several trials, the researchers determined that a change of BMI of approximately 1.33kg/m2 is required to make a difference noticeable.
"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," said Re.
In summation, to make your face look more attractive, you'd need to lower your BMI by about 2.5 points. That means that a woman and man of average height would need to lose about 14 pounds (for women) and 18 pounds (for women) for others to notice a significant change in weight.