Can hypnosis make me a healthy eater?

• ​How hidden sugar lurks in 'healthy' modern diets
• Good Food Guide Editor Myffy Rigby's health diary

You could avoid grains and stop drinking and put chia seeds in your oats and exercise and do all those difficult, boring, willpower-sapping things that people do to lose weight. You could fight your urges, uproot your habits, and slowly, painfully grind your excess fat out of existence.

Or you could just ... desire less food. This is the basic idea behind weight-loss hypnotherapy: that it couldn't be easier. You just go for a few sessions and then you don't need to fight temptation at all, because you don't even feel it. For an existence untroubled by the allure of sugar, it sounds pretty sweet.

It also sounds pretty fanciful. As with any weight loss treatment, if it worked every time, you'd already know about it. That was my second reaction when my editor asked me to go and try it, the first being indignation that he viewed me as ripe for some fat-shifting, like a prize hog swollen for slaughter. Incensed, I whipped the apple from my mouth to tell him just how angry I was.

Then I agreed to go: it was a couple of weeks after Christmas and I was just under 22 per cent body fat, which is not atypical for me but equates, on the scale of nought to Cristiano Ronaldo, to whatever number looks most like a doughnut. I had long preferred the idea of being a stone and a half lighter, but my body always seemed to disagree. Maybe I could hoodwink it.

So, one lunchtime in early January, I went to see Susan Hepburn, a hypnotherapist who has been credited with helping Lily Allen drop three dress sizes and Nigella Lawson lose 12 kilograms. At her Harley Street clinic, she led me up to her dim, high-ceilinged, first-floor room and we began the session with a discussion of my eating habits.

Soft pipe music played in the background as she told me I was going to eat clean, light, healthy foods, reduce my snacking, eat slowly and so on.

I've always been greedy, I explained, and it would be great not to be. I told her about my insatiable appetite for crisps; and various other aspects of my weirdo diet, which at that point was composed predominantly of meal-replacement shakes and vegan meat substitutes. She noted this stuff down, probed me to recall the first time I ate when I wasn't hungry (unfortunately my greed far predates the development of my long-term memory) and asked what results I wanted. "Er, 15 per cent body fat?" I suggested. You can go lower, she said. We settled on 12, and a 10-centimetre reduction in waist size to 28.

It was time to start the hypnotherapy. It won't feel like it's working at first, Hepburn said, but it will later. She sat me on a reclining chair and told me to close my eyes, and then began speaking in a soft, occasionally sonorous voice that rose and fell like waves.

"Breathe in and out, down the diaphragm, and hold that breath ..." she began. Rest, she said, and concentrate on "the idea that you have a window on to your mind. We're going to let out all anger and fears and worries ..."

She asked me to relax my shoulders, arms, chest, all the way down to my legs and toes. Soft pipe music played in the background as she told me I was going to eat clean, light, healthy foods, reduce my snacking, eat slowly and so on. She told me she was going to erase my early memories of overeating (a shame! They were good times!) and by this point I felt relaxed and mentally absorbent. After about 15 minutes, she counted down to 10 and asked me to open my eyes. I felt like I'd had a nice lie-down, not a life-changing treatment, but, as she reminded me, the effects would kick in later.

I went back to the office and then the weirdest thing happened: I didn't want snacks for a whole afternoon. Imagine. When a colleague offered me some chocolate, I had a single square and was entirely spared my usual craving for more. My stomach just felt ... full. The phantom meal in my stomach hung around for two or three days, and in the weeks after that I continued to willingly eat more virtuously and sparingly. After eight weeks, two sessions, and daily listening to the recording Hepburn had made of our session, I had lost four kilograms, and my body fat had fallen below 20 per cent.

It felt good, and, placebo or not, I'd had that interesting experience of fullness. There are some caveats, however. It definitely helped that I hadn't been drinking in January; it's normal for someone's weight to go back down after a period of festive weight gain; Hepburn instructed me to note what I was eating, which in itself made me more self-aware and less likely to eat rubbish; and, crucially, I was particularly motivated by the unique millstone that is having your weight loss documented in a national newspaper.

Anyway, whatever, it was great. But then ... it stopped. I reached the lower bound of where my typical weight might be, and then I didn't lose any more. Hepburn gave me a remedial session, which gave me a similar but shorter-lived effect to the one I'd had after our first meeting, and reminded me to keep listening to her tape and to keep noting down my meals. It's now four months since that first session and I have remained about three kilograms lighter than I was in January.

The evidence for hypnotherapy's efficacy is of course mixed, but clearly it works for some people. Guy Hands, one of the city's leading financiers, said this week that hypnosis helped him overcome his roast-potato addiction.

Sadly, I didn't get near my target of 12 per cent body fat, but for what anecdotal testimony is worth, I do appear to have permanently lessened my snacking vice. Crisps, I fear not thee.

The Telegraph, London

Hypnotherapy - should you try it?

How does it work?

By inducing a state of suggestible relaxation - hypnosis - in the patient, say practitioners, which allows them to reprogram the unconscious mind. The patient, contrary to popular belief, will stay awake and alert and remember the session. The practitioner won't use a gently swinging pocket watch. It's important that patients want the treatment to work.

What's it used for?

Apart from weight loss, hypnotherapy is often used to treat addictions, change habits, reduce anxiety and relieve pain.

And, um, does it work?

Hypnotherapy, as the sceptics' encyclopedia Rational Wiki puts it, "is not widely endorsed by the medical and psychiatric community as a primary therapy". It's easy to find anecdotal evidence in its favour but just as easy to find examples of its failure. There are many studies showing hypnotherapy's effectiveness in treating a range of conditions, particularly pain. However, it is far from universally reliable and depends greatly on the willingness of the patient. It should never be used as a substitute for evidence-based medicine.

What are the risks?

Some therapists attempt to recover patients' repressed memories, but these patients sometimes accidentally create false memories. Hypnotherapy, the NHS warns, can exacerbate psychosis and certain types of personality disorder. If you're looking for a private hypnotherapist, the NHS recommends you choose someone with a healthcare background who is trained in working with your condition and registered with a body which is accredited by the Professional Standards Authority.

The Telegraph, London