Lionel Shriver makes a distinction:
Socially, cosmetic transformation makes a big difference—an appalling difference. And maybe the discipline of regular exercise builds mental muscles for the pursuit of more important goals. But beyond that, our contemporary equivalence between the self and its ever-corrupting, malady-prone shell profoundly diminishes what it means to be a human being. After all, it’s hard to imagine ever commending one friend to another, “Oh, you’d just love Nancy, she’s so thin!”
Beauty is especially prone to assume the status of be-all and end-all to those who believe they’ve been denied it. In truth, feeling beautiful is an elusive sensation—dangerously dependent on other people, sometimes mystifying or even disquieting, and forever undermined by insecurity that, with one fatal pint of ice cream or foregone set of sit-ups, it’s over. For many whom others regard as hot stuff will squander their attractiveness on scrutinizing themselves for flaws, fearing their looks have faded, and, these days? Feeling fat.
The Dish 