It's a funny thing really. The notion of bustier women being more beautiful along with the ads to gain weight that floated in abundance in the 1950s-1960s are just the same as our ads today that sell diets as if they were a cookie. The society, whether fifty years earlier or not, were telling a portion of the female population that their body type wasn't pretty and they should buy food and diets and magazines that would help them achieve such a thing. Just because gaining weight is a lot easier than losing it (to an extent, I know some people who struggle with gaining weight) doesn't mean that the prevalence of weight gaining ads in the 50s is okay.
People don't realize that it's the exact same thing, just in reverse. By saying the 1950s had it right and we have it wrong, still isn't advocating for all body types.
I'm not going to sit here and ramble about how we should love and accept everyone boobs or no boobs, ass or no ass either. I'm just here to say, hey, think it through.
I know of several people I follow on Twitter who readily "retweet" posts about how we should go back in time to 50 years earlier because they "had it all right".
Just read the above ad, "If you are a normal healthy, underweight person and are ashamed of your skinny, scrawny figure, NUMAL may help you add pounds and pounds of firm attractive flesh to your figure." Note the use of ashamed, scrawny, and attractive in the ad. Funny how society still hasn't changed.
Have a fabulous day.