Women aren't as weight-conscious as we thought them to be.  Researchers from the University of Texas Medical Branch did a study and found that one-third of 466 women of various ethnicities they observed over a period of 36 months, didn't notice that they'd gained about 4.5 pounds (2 kilograms) over a six-month period.  That's not all. Contrary to our image of fat, black women, African-American women were more likely than white or Hispanic women to notice they'd gained weight. 

Maybe, women know what weight they are comfortable with. Maybe, women know when their weight starts giving them problems, until then it's okay.