One day earlier this month, I opened The Oxford Companion to Food, for so long a bible to me, and looked up sugar. The entry ran to several pages, taking me from its composition (carbon, hydrogen, oxygen) to the various forms it takes (dextrose, fructose and so on), and then to its sources in nature (honey, cane, beet). Finally, there was a section titled “Sugar as a Food”. This dealt, in a way that already seems rather old-fashioned (the book, edited by the late Alan Davidson, was published in 1999), with the difference between white sugar and brown. The latter, the writer stressed, is not healthier than the former; and while overconsumption of both kinds may lead to obesity, this is not the fault of sugar, but of those who eat too much of it.

It’s been a long time since I heard anyone suggest that brown sugar is healthier than white; it’s the kind of thing my granny might have said in 1979. But it wasn’t this that caught my attention. What surprised me was the writer’s firm placing of the blame for sugar-related weight gain on human beings rather than on, say, the industries that relentlessly push sugar our way in the form of fizzy drinks and ready meals. Nor had he mentioned the now well-established connection between the overconsumption of sugar and type 2 diabetes, cancer and even, it is thought, Alzheimer’s disease. Having registered this, I was then surprised by own surprise. Once, I would have read the words “the fault of the people who eat too much of it” and nodded my head. Now I was shaking it instead.

My mantra used to be: all things in moderation. But I have to accept that this is no longer the case. Thanks to the American journalist Gary Taubes, a long-time opponent of the old dietary advice that insisted healthy eating involves avoiding fat, and to those others who’ve since taken up his cause, I’ve grown, slowly but surely, ever more anxious about sugar. Thanks to my mantra, I never believed fat was bad in the first place. Even as everyone began spreading St Ivel Gold on their toast, I stuck doggedly with butter. But when, more than a decade ago, Taubes set out to prove it was sugar and refined carbohydrates that were doing people the most harm – a heresy in public health circles – it was impossible not to listen. You had only to visit a supermarket to see how bodies were changing. You had only to open a newspaper to read what a deleterious effect this mutation was having on the nation’s health.

Taubes’s latest book (the reason why I looked up sugar in the Oxford Companion) takes his argument one step further. In The Case Against Sugar, he has no time for my enduring conviction that a calorie is a calorie, irrespective of where it comes from. Sugars, he believes, have a “unique physiological, metabolic and endocrinological effect” on our bodies. They trigger “insulin resistance”, the condition that leads to diabetes and other diseases, for which reason we should avoid them. I thought about this quite a lot as I finished the last of the season’s Roses. I eat relatively few processed foods, a happy by-product of the fact that I like to cook, and I’ve never been one for fizzy drinks. Still, I’m a sucker for cake, that very British treat, and I often add sugar to things to make them taste better: a dash in salad dressing, a pinch in tomato sauce. Plus, I eat fruit, which I gather Taubes regards as an indulgent treat. (I won’t ever give up fruit: eating has as much to do with pleasure as with health.)

It’s not all about me, though, is it? I used not to be able to picture it, the white stuff that was going down people’s necks in such seemingly vast quantities. Then I began reading labels. Sugar is in everything, from stock cubes to roasted peanuts to salami (I won’t ever give up eating salami, either). If I’m eating this much hidden sugar, what are others consuming? Quite a lot, is the answer. Perhaps you had the misfortune, last week, to watch ITV’s egregious reality show, Sugar Free Farm. As the series began, one of those who was consuming the most sugar was the actor Peter Davison, a charming, sensible-seeming man who did not appear to me to be vastly overweight. He eats (or ate – we shall see) 52 kilos of sugar a year. Just imagine it. Piled up, it would fill your downstairs loo. Two days into cold turkey, it was Davison, rather than, say, Gemma Collins from Towie, who came over all dizzy. The paramedics took him away in an ambulance, just another pitiful, trembling addict.