Any leftovers from pre-Christmas tins of Quality Street have been locked away and replaced by very thin slivers of apple and discussions about portion control.
I am not usually one to be coerced into giving up the thing I love most (namely food), but having recently been trailed by a group of giggling Year 6 girls, who stopped me in the corridor and affectionately asked me whether I was pregnant, I realise that I, or more precisely, my belly, is not immune to the consequences of seasonal excess.
So I have decided to pay attention to the breaktime musings of the boiled water brigade (a hardcore group of teachers who have denounced coffee granules and teabags), and am learning how to put the zing back into my eating habits.
I am happy to be reminded that fresh produce is best and that every food group needs to be represented at mealtimes. I am not so happy, however, to be told that servings should fit neatly into the palm of the hand - that's a fist-full of rice, or a palm-sized chicken breast.
I look down at my hands (which are particularly small) and start to despair.
But never mind, boiled water fanatic number one consoles me - on this diet you can eat as much leafy green salad as you like. Well, thank goodness for that.
On second thoughts, I think I might just sit back with a large bag of salted pistachio nuts and a can of (non-diet) Coke, and learn to be at one with my pot belly instead.
And when the curious enquire whether it was a boy or a girl, I will tell them all about the wonders of Marks and Sparks's support underwear Louisa Leaman is a London teacher