Its not just a beauty ideal. Good grief. A women with higher than 0.9 starts to have health problems, because of visceral fat. They actually found that WHR is a better indicator of health
problems than BMI. The ideal for a women is 0.8 for health reason, not esthetic reason.
That it is more attractive is just an added bonus.
BTW, I'm 40 and I've been within 10 pounds of 175, all my life. Now, I'm 155,
with a minimum diet change and slightly more activity in one year. You'll
probably find me a bitch for saying that, but most TS and GG that have excess
weight is because of the wrong diet and exercise. I'm CERTAIn that
if they actually change how and what they eat and exercise they will lose weight
and look AND FEEL better.
I'm not even talking becoming hyper thin, coming back to a WHR=0.8 and
a BMI lower than 25 doesn't mean your super thin. You may be 10-15 pounds above
the ideal weight, but still your within the healthy range.
Since many women don't have children, or a small number not sure you can
really blame that for gaining weight. After menopause, women tend
to gain weight in closer to male pattern because of declining estrogen
values (which directs fat to the hips/buttocks area before that).
But, its inactivity and bad diet over a long period of time,
at any age which leads to being overweight.
Fat is not gained in one event like pregnancy. Most women come back within 5 pounds of their
pre pregnancy weight within one year. Its cumulative neglect which has led women
to edge closer and closer to 0.9. Once you've got visceral middle fat, it messes up
fat distribution even more and you gain mostly in the middle UNLESS you exercise.