A lot of those Manhattan ladies are neurotic grass-eaters who haven't had a really good meal in years. Not the best examples.
Becoming a competent cook and using quality ingredients is one of the best ways to stay thin, as that will cut an enormous amount of sugar and refined starch out of your diet. You also discover that you like a lot of things that you thought you didn't; many relatively healthy things taste far better than most people imagine simply because they've only had badly prepared versions made with poor quality ingredients.
Well, I don't know what the beautiful Manhattan ladies eat, but perhaps you are right. I first noticed them a few years ago while jogging in Central Park during a visit to NYC. At the time I was jogging 3 miles most mornings, yet many of the ladies were able to outpace me...'course they were likely 20 or 30 years younger than me...anyway, they were in shape. I figured they were showgirls or actresses, people who needed to look sharp for professional reasons. Anyway, these days, whenever I visit Manhattan, I notice them around.
Agreed with your points about cooking, eating and refined starch. Both me and my wife cook pretty well, neither of us has ever had much of a weight problem.