This is true, for many, but not all men. What you are describing is someone who is healthy, not anorexic or morbidly obese. However within that healthy range, is still a wide variation, dancer slim?, athlete muscular?, curvy?...it is personal taste. I will add, that
some men like the less healthy heroin-chic look, or the big-beautiful type. It's a bell curve. Less at the extremes.
I have found that
most men like a woman with "a little meat on her bones". 
I've spoken to men and 99% say they'd rather hug a woman who's a little "fluffy" rather than a bag of bones. They don't like wrapping their arms around a skeleton. When it comes to men, neither do I. I prefer someone I can wrap my arms and not feel his ribs when I hug him.
Besides, if one desires to do the horizontal mambo, those hipbones can be dangerous.
However,
very few men are turned on by a 300-pound woman, no matter how beautiful she is on the inside.