The author and psychotherapist Susie Orbach wrote recently that she thinks slimming clubs give women unrealistic expectations about weight loss. Speaking at a parliamentary inquiry on body image, Orbach said that slimming clubs lock women in "straitjackets for the rest of their lives". This pronouncement is utterly wrong. I should know, because I was fat, and I attended the slimming club Weight Watchers for over a year.

The turning point for me wasn't that my clothes looked bad – I was used to that. It wasn't even that a size 16 was too tight. It was when I went to the doctors for a routine blood test and I was told I had high cholesterol. Now, that came as a shock – I was only 26. Who has high cholesterol? I always assumed it was "properly" fat people, like the really unhealthy ones that look a bit grey as if they're ready for the mortuary slab. It was then that I realised I'd had enough – it was time to actually make a real change.

There's nothing like getting on the scales in front of a terrifying "leader" called Judy to keep you on the straight and narrow. She didn't hold back if I slipped up and put on weight, but she was right – I did need to try harder. That feeling was horrible; nothing felt worse. But it made me motivated. Each week the number went down as did my cholesterol. I eventually lost just over two stone and, although I know it's such a boring cliche, I really do feel great.

The difference between slimming clubs and diets is that the clubs have a structure, regular weigh-ins and food diaries that you're encouraged to keep. This gives people the lasting tools to lose weight. To say that these clubs are a "straitjacket" is ridiculous. The whole idea of it is that you eat less and exercise more. It's not rocket science and it's exactly what your doctor would tell you to do, just with regular support and a group of people in the same boat as you to help you on your way.

Slimming clubs seem a perfectly sensible way of losing weight to me. I had no illusions of ending up looking like Beyoncé or being a size zero. I just wanted to be healthy. Our terrifying leader Judy didn't like you to lose much more than a pound or two a week – anything else was too quick and unrealistic. There was no "lose a stone over a weekend" or "get a flat stomach by drinking this vile milkshake". I liked that nothing was forbidden. Everything had its points value, so if I wanted a Walnut Whip, I ate one. I just didn't have that with an added McDonalds for lunch and six pints of cider.

I haven't been to a class in six months. I got bored. But I've now got a sensible set of guidelines that I can always use to make sure I never get unhealthily overweight again. I think Orbach is over-thinking the whole thing. Perhaps she's never had to squeeze into a size 16 in a Miss Selfridge dressing room. There's no denying that there is all sorts of unfair pressure on women to look good. I can just think of a lot worse culprits than slimming clubs.

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