We all know short-term fad diets don't work. We know that long term they make us fatter, mess with our metabolism, upset our hormones, and turn us into calorie-counting psychopaths if we don't leanr to eat healthily and get regular exercise.
As if we needed further proof, a new book – 'Why Diets Fail (Because You're Addicted To Sugar)' – spells it out.
Written by neuroscientist Nichole Avena and John Talbott, a financial and political analyst who kicked his own sugar addiction, it suggests that the only way to a lasting healthy weight is to go cold turkey from sugar and everything will fall into place.
Or rather, fall off the places that sugar has been helping to expand. The only snag is that sugar, in its myriad forms, seems to be in everything apart from spinach.
It's not like I didn't know that I was hooked on sugar when, two Januarys ago, I paid a man six grand to insert a silicone band high into my abdominal cavity.
I also knew I was three to four stone overweight, and could not face another diet.
I knew diets didn't work for me , because I had done so many of them – Weight Watchers, Slimfast, Lighter Life, GP-prescribed weight loss medication that made me bonkers, and a bewildering assortment of psychological approaches.
From Harley Street hypnotherapy (from the £275-an-hour hypnotherapist who shrank Lily Allen, no less) to various 12-step food programmes that advocated abstinence from sugar, white flour, snacking, and asking a higher power to remove my obsession, I tried it all.
Oh, and psychotherapy, homeopathy, naturopathy, Bikram yoga, Bergamot oil. Swimming, cycling, cross-training.
You name it, I did it. Everything worked short-term, nothing worked long-term.
So, in desperation, I thought a gastric band might be the answer.
This was not about wanting to look slinky in a pair of jeans, or buy clothes with a particular size number on the label.
It was not about kowtowing to the cultural message shouted at women a million times a day that the less physical space you inhabit, the more social respect and sexual desire you are accorded.
I absolutely do not buy into any of that – although obviously I would prefer if my shadow didn't require its own post code.
No, this was (mostly) about long-term health.
I had been clinically obese for over a decade, since my first pregnancy in 2000, where I had gained five stone in nine months – yet to my great surprise, had not given birth to a five-stone baby.
So I was still carrying a lot of it, and my BMI was 36 (healthy weight is between 18 and 25 – serious obesity is 40 and above).
A single mother in my mid-40s, I was horribly aware of the health implications of long-term obesity – I'd already had cancer in my 30s caused, said my oncologist, probably by too much smoking and booze.
I packed them in, but not the sugar. I was starting to feel achy, creaky, dopey, grumpy. Something had to be done.
As we become fatter and our exposure to the concept of weight-loss surgery increases, so too does our knowledge.
We know the difference between a gastric band and a gastric bypass – the latter is irreversible, and requires rerouting part of the digestive system.
The band, which is not irreversible, involves keyhole surgery under general anaesthetic. A small white silicon doughnut-shaped band is placed around the top of the stomach.
Attached to the band is a long thin tube, with a stopper at its other end – this is the port through which the width of the band can be adjusted via saline injections.
The more saline is injected into the donut, the narrower the access to the main stomach area.
The idea is to cordon off a golfball-sized area at the top of the stomach above the band, so when you eat a small amount of food, you feel full.
It sounded like a genius idea, so after lots of research and deliberation, and after borrowing the money, I was ready.
I had the procedure done in a private hospital which has clinics all over Ireland and the UK. The hospital looked like a hotel – it also did breast implants, face lifts, nose jobs, cosmetic dentistry, liposuction, and many other cosmetic procedures.
A year after the operation, there had been no weight loss. In fact, the unthinkable had happened – I'd actually gained a small amount of weight.
My GP had suggested that this might happen – another of her patients had changed her eating habits post-banding from three big meals to many smaller ones, and gained weight. Don't be daft, I'd laughed. That won't happen to me.
Except it did. I was hungry all the time, but could not get much food down.
The food that got blocked was the healthy stuff – broccoli, rice, Quorn, anything chewy and dense.
I spent a lot of time regurgitating blocked food, which is exactly as unpleasant as it sounds.
What did not get blocked were the addictive high-fat high-sugar melty foods that had made me fat in the first place – Ben & Jerrys, Green & Blacks. Those foods just slid down.
Turns out the band was too tight – so they removed some saline, which made eating easier, thus reducing the cravings for high-energy foods.
But the whole point was that it was supposed to restrict food intake, wasn't it?
It was starting to dawn on me that this was not quite the miracle cure I had hoped for.
"While 80pc of patients have a good response to gastric band surgery, between 10pc and 20pc have a sub-optimal response," says obesity expert Professor Carel le Roux of Imperial College London.
"This is not the patient's fault – the band doesn't help everyone. As a procedure to lose weight, it is very poor.
"As a treatment for what you see in the mirror, the gastric band is rubbish.
"But as a health benefit, it is marvellous. They make patients healthier.
"You have to change the biology before you can change the psychology."
Professor Le Roux says that most obese people continue to gain 1-2kgs per year, and that the band stops this continued gain.
Also, while a 5pc to 15pc weight loss might not make much of a visual difference, in terms of health, it does.
Over 70pc of band patients are women, which confirms the cultural pressure to conform to a prescribed body size, ie thin.
Richard Welbourn, president of the British Obesity and Metabolic Surgery Society, (BOMSS) agrees.
"Bariatric surgery doesn't make you thin or happy, but it improves your health," he says, adding that most patients experience 50pc to 60pc loss of excess weight within three to four years.
"So you might still look fat, but physically you are in better nick.
So were my expectations unrealistic?
Did I imagine the band was some kind of magical device?
A friend recently had a gastric bypass done privately in Belgium, where it is much cheaper, and tells me her surgeon offers packages of band removal prior to bypass surgery.
I briefly considered a bypass, as it had worked so successfully for her, but it seemed too drastic, even if I could have afforded it, which I could not.
The only difference, says Richard Welbourn, is that bypass weight loss is faster. And sometimes when bypass patients regain weight, they need banding.
Meanwhile, fed up and still obese, someone recommended a personal trainer.
He turned out to be affordable, motivational, and engaging. I began to get fit again, and to connect with my physical self.
I rejoined the gym, and finally discovered a form of exercise I actually love – doing weights, on my own.
I get high on the endorphins, which makes me keep going.
Then I changed my diet permanently from vegetarian to vegan, and discovered it's quite hard to eat badly without eggs, dairy or processed foods.
I am still a sugar slave, but these days it tends to be 'good' sugar – fruit, moderate amounts of dark chocolate – and I balance it out with regular, consistent exercise.
The punchline is that until I spoke with Carel Le Roux and Richard Welbourn, I had actually wanted to have my gastric band removed.
It gets in the way of exercise, especially yoga or anything involving abdominal work.
But the fact is that I am much healthier than I was two years ago.
The band is preventing further weight gain – it is a stabiliser.
The rest seems to be down to me – down to daily consistency with diet and exercise.
I have discovered the long hard expensive way that there is no quick fix. And anyway band removal costs five grand – so unless I win the lottery, it's in there for good.
Expensive mistake or long-term weight management aid? To be honest, I have no idea. I haven't a clue.