At 236lbs he went to interview the diet guru Dr Atkins - a cry for help masquerading as a professional assignment - and Atkins explained why Leith could never get enough of buttered white toast. The butter isn't the problem: we eat 15-per cent less fat than we did when Atkins invented his diet in 1972, and we're 20-per cent fatter. The white bread is the problem. When you eat carbohydrates your blood sugar level goes up and your pancreas produces insulin to drive it back down, making you hungry again. If you overeat carbohydrates you overproduce insulin, your blood sugar levels crash and you get uncontrollable cravings.
So carbs and sugar can never satisfy you. Like pornography, slimming products, nicotine or cocaine, they offer a short-term fix but always leave you wanting more. That's why there are so many hundreds of sugary and carbohydrate snacks on the market: they're the perfect product. And that, thinks Leith, explains why each time there's been a resurgence of interest in the Atkins diet, a powerful backlash swiftly followed. (Just as this book was published, sales of Atkins products were revealed to have crashed.) Low-fat diets promote the sale of low-fat products, but Atkins had nothing to sell and his low-carb message was potentially very damaging to the food industry: "Carbs are powerful. Carbs have influential friends."
By cutting out carbs Leith eliminated his cravings, and has since maintained a fairly ideal weight of around 200lbs. After a while he reintroduced a moderate amount into his diet without feeling the urge to binge, and he even had the odd drink or two. Then three or four more. And a few lines of coke as well. Then three or four more of those. And then he woke up in a stranger's house, bleeding and in a pool of his own vomit, realised that his compulsive behaviour was symptomatic of a deeper problem that Dr Atkins couldn't help him with, and booked himself into therapy.
So carbs weren't really to blame for Leith's obesity. As The Hungry Years closes we find him learning to blame his parents for sending him to be bullied at boarding school and for never noticing how abandoned he felt. But that's material for a different book; a more self-indulgent and less interesting book, about his own personal woes.
The Hungry Years, on the other hand, because Leith owns up to the fact that "if we have a core problem, here in the Western world, I am an embodiment of that problem", is a book about all of us who live in a consumer society which teaches us to be dissatisfied and to crave what we haven't got, and which promises to sell us a quick and easy solution to the problems that it creates.
So, with a good newspaper columnist's flair for spinning interesting parables out of the mundane fabric of his own life, and in little, compulsively readable, bite-sized chapters that always leave you wanting to read more, Leith writes about glossy health and beauty magazines which make their readers feel insecure enough to purchase the products manufactured by companies whose adverts pay for them. About brightly packaged headache tablets, which are now consumed in such high quantities that they're giving people headaches. About mobile phones and Catherine Zeta Jones, Dawn French and French fries, about clothes, plastic surgery, self-help books, strip clubs, casual sex and drugs.
Because the Atkins diet worked for him, because he absolves so many of our insecurities, because he writes so frankly and without pity about the most mortifying moments of his life, and perhaps, too, because he's a man writing about vulnerabilities that only women usually admit to, it ends up being a rather reassuring book. So go on, buy yourself a copy. It really will make you feel much better about yourself, I promise.