I wanted to diet to set a good example to my children

In May last year, when I decided to attend my first local branch meeting of the Rosemary Conley diet and fitness class, I was slightly desperate. The scales put me at more than 14st (89kg), which, at 5ft 5in, gave me an "obese" body mass index (BMI) of 31 (the norm is between 20 and 25). This had happened to me in increments: too much weight put on during two pregnancies, too many bad habits (chiefly, continuing to eat as if I were still pregnant), too little exercise.

The weight itself did not bother me that much. It's just a number and I was probably even heavier than that while pregnant. But I hated that BMI figure because I knew what it meant: I was a medical liability. I had a problem and it was one that I needed to sort out sooner rather than later.

My weight has fluctuated all my life. My mother was permanently on a diet while I was a child and always telling me I had to be careful not to become "fat". (She herself has always been a size 12 but would rather be a size 10.) I don't blame her for my weight: virtually everyone I know who grew up in the 1970s had a mother like this. As a child, though, I was never large. I was a voluptuous student perhaps, but it wasn't a big deal.

It was only after university that my weight began to creep up because of an over-consumption of biscuits, alcohol and takeaways (there is no attractive way to portray it). At the age of 25, I dieted, lost 2st and was almost slim. But by last year, aged 35, the weight had gone back on – plus extra.

As anyone who weighs more than they should knows, there is no great mystery to piling it on. You eat a bit more here and a bit more there. Certain foods start off as treats and, before you know it, they are everyday indulgences. I was not a miserable porker by any means: I love eating and fully enjoyed not denying myself anything. It was only when I realised that I was becoming increasingly unhealthy – and setting a terrible example to my children – that I realised I needed to change my ways.

I was feeling increasingly uncomfortable with the idea of my daughter Vera, then two, growing up hearing me talk about being on a diet, denying myself food or stressing about looking large. I lived through all this with my own mum and the outcome was not healthy. For some reason, I wasn't as worried for my son, Will, aged five: he doesn't seem to have any hang-ups with food. Vera, however, copies everything I do, so I need to be doing the right thing. I wanted Vera to see me eating whatever I wanted in sensible amounts, enjoying healthy food and exercising regularly. It dawned on me that if I didn't do it before she turned three this summer, it would be too late: she would already be absorbing all the wrong messages.

So for the past year, I have attended the Rosemary Conley classes in my local area (Teddington and Twickenham in south-west London). It costs £30 a month for unlimited classes: a weigh-in, motivational talk and 45 minutes of aerobics. Sometimes I'm a bit slack and go only once a week. Other weeks, I'll go four times. In the early weeks I lost up to three or four pounds a week. In the first six months I lost two and a half stone.

The next half stone has taken another six months and is still not really off completely – it goes up and down. To my great annoyance, my BMI is still not quite down to 25 (I need to lose another 4lb) but I'm becoming less bothered. If anything, I'm now a bit bored of the tyranny of the scales.

The diet itself is very easy. You just have to be disciplined. They give you a booklet that contains hundreds of meal choices. Breakfast is typically cereal; lunch is a salad or a ham sandwich; dinner is pasta with a tomato-based sauce, or lean meat or fish with vegetables. And they figure in treats too: three Cadbury's fingers a day or a Jaffa cake here or there. I must admit, though, that I struggle to follow the maintenance diet now that I've lost the bulk of the weight (it is quite punitive if you love eating). So, instead, I eat more or less what I want – but in far smaller quantities than before – and try to compensate by doing extra exercise.

The best thing has been how I feel around the children. They notice how much I enjoy the exercise classes. In general I'm more active: if I have to miss classes, I'll go running instead. I've also started Pilates – which I hadn't done in more than five years. My biggest enemy, though, is complacency. I recently missed two weeks of classes, and Jaffa cakes started "disappearing" from the kitchen cupboard. But I do have a safety net now. I feel a certain comfort knowing that the classes are always there, and I can always up the dosage if things get out of hand.

I'm quietly vigilant around my daughter and I notice already that her attitude to food is different from mine. She will happily leave half a piece of chocolate cake if she doesn't want it all, something I find both inspirational and puzzling. (I always found it impossible as a child to leave anything sweet on my plate, and I still struggle with this as an adult.) I say very little about food to my children because I know my own attitudes are a bit warped. Nothing is forbidden to them and I try desperately hard not to refer to biscuits, sweets or chocolates as "treats".

I try to keep it all as neutral as possible. As a result, so far they eat everything and don't fixate on anything. If only I could say the same for myself. And so the battle goes on

Thanks to guardian.co.uk who have provided this article. View the original here.