I've just joined a new club, new to me that is. I more than fulfil all the conditions for membership (well, one condition actually) and how I wish I didn't.

Groucho Marx was right when he said he didn't want to belong to any club that would have him.

I don't want to belong to this club but I'm more than eligible to be a member ... unfortunately.

A few years ago I would never have gained admittance - a few years ago I would never have thought to apply for entry.

But I'll say one thing for this club; it's certainly not elitist.

When I went along to enrol I wasn't asked for details of my educational achievements, annual earnings or whether I considered my family to be comfortable Old Money or flashy nouveau riche.

No, I was asked whether I had at least 10lb in weight to lose.

"Considerably more," I said. "Double that amount, add another ten for good measure and you're getting warm."

And so it was I found myself at my first meeting of WeightWatchers.

The only requirement for membership is that you must be carrying excess fat - it doesn't matter where, so long as it's all your own work.

I went with a friend who weighs the same as me but is several inches taller.

If she's overweight that must mean I'm verging on the morbidly obese. We reckoned a bit of healthy competition would keep us keen. We could award each other prizes and the like.

First we were weighed and yes, it was in public but it was all very discreet. Your weight isn't disclosed or discussed with anybody but yourself.

Instead you're advised on what weight would be desirable for your height and how many points a day you may consume in order to reach your target. And yes, I did say points, not pints.

Every item of foodstuff you might normally be tempted to swallow carries a certain number of points - the good (boring) stuff like lettuce and cabbage are point-free but the bad (delicious) stuff like chips and ice cream are full of points as well as excess calories.

It's not too punitive if you are able to eat in moderation but then if we could eat in moderation we wouldn't need to be weight watching, would we?

One scoop of ice cream, for instance, equals two-and-a-half points but what about those of us whose demanding appetites are only satiated when we've spooned up the last creamy drops from a 500ml tub of Ben and Jerry's Phish Food?

How many points have gone down the throat then? Too many to count in all probability and I'm only allowed 20 for the entire day.

After the first week I'd lost just 0.5lb while my friend had shed three and a half.

"Well, you won all the honours this week," I said glumly.

Then I cheered up. "Which means, I suppose, that I get the consolation prize," I added.

"And what's that?" my friend asked.

"A 500ml sized tub of Ben and Jerry's Phish Food," I told her.

"You can't!" she said. "You'll be guzzling an entire day's points, probably two entire days' points, at one sitting."

"That's the reason I'll be doing it," I replied defiantly.

"In fact, you could say it's the whole point ...!"