Thousands of teenage hopefuls glued to the Channel 5 series Make Me a Supermodel at the end of last year learned that a size 1012 is simply too fat. As if that message was not sufficiently disturbing, newspapers covered the death of Brazilian model Ana Carolina Reston whose supermodel diet of tomatoes and apples proved fatal.
Even on the somewhat ironically named Breakfast Television, Paul McKenna promised to make us thin. This is sizeism gone mad, timed to address the collective guilt of Christmas indulgence.
We have a serious national problem with obesity as "convenience" rules the kitchen. But of equal concern is the growing epidemic of eating disorders and the worship of the unattainable size zero.
Our love-hate relationship with food sits uncomfortably within an appearance-obsessed culture. It is one where politicians are subjected to sartorial scrutiny more rigorously than their policies ever are, and where TV style gurus claim to change lives by changing fashion sense.
Those of us tasked with teaching young adults about healthy living, trying to nurture their burgeoning self-confidence, battle against the lure of a powerful, often unbalanced media message.
For all the apparent concern in recent months, designers are still recruiting painfully thin models, still approaching diagnosed anorexics to offer contracts.
Aspiring starlets still haunt the tabloids and gossip magazines in their double zero-size dresses.
Any anorexic will tell you that, in some bizarre way, rejecting food can be enormously liberating. It represents the ultimate act of control in a world where she has been monitored and controlled, regulated and assessed at every turn. The designers and retailers have a lot to answer for. However much we deplore its shallowness as a concept, dress style offers developing young adults an identity amid all the confusion of puberty. It provides a means of instant social inclusion.
To be denied access to a particular fashion because of your size is more significant than designers can imagine. Memory carries me back reluctantly to the mid-1960s, and the agonies of trendy boutiques where everyone sought to look like Twiggy. Larger women in those days were outcasts, and scurried furtively into "the outsize shop" for their baggy crimplene numbers.
Outsize meant outside what was normal, acceptable or desirable.
It is much easier and infinitely less embarrassing to change shape, to stop eating and aim to be a "nothing", and thus conform to what the designers and retailers have decided is acceptable. Theirs is the power to determine which bodies will carry their creations.
But perhaps there is some hope. In the United States, Dan Kindlon, Harvard child psychologist, has recently encountered a new breed of teenage "alpha girl", confident, assertive, ambitious and free of gender stereotyping.
"The alpha girl doesn't feel limited by her sex," he writes. "She is a person first and then a woman."
Girls in the UK are achieving more than ever before. We must help them to feel good about themselves, to be healthy and active, to be confident enough to reject the pressure to morph into what others want them to be. We must alert them to the power of the media to control their perceptions, and help them identify fantasy media creations from the truth.
Dr Brenda Despontin is head of Haberdashers' Monmouth school for girls