Food is never just food; as any vegetarian who found herself eating a pork pie before a 20-week pregnancy scan will know. Sometimes we eat for pleasure, sometimes we eat for fuel, to feel better, out of boredom, because we’re sexually frustrated, sad, or any number of other reasons. In her new book Grace Dent explores the particular way in which we all, from time to time, eat for comfort. Most importantly, she looks at what we shove, flat-palmed, into our faces when nobody’s looking and what this tells us about the human condition. The book draws on the three years Dent has spent as the presenter of Comfort Eating – a Guardian podcast in which the food writer invites celebrity guests to her house to eat the kind of snack that they most certainly wouldn’t be serving up to a dinner party. Potato waffles with spaghetti hoops, fried bread sandwiches, beans on toast with crushed Wotsits; starchy, dripping, saturated morsels of pure, vitamin-free delight. But what Dent really wants to write about, it seems to me, is nostalgia. This is a book shot through with a certain kind of recollection of northern, working-class family life in all its funny and poignant detail. As Dent puts it herself: “There’s nothing about life in late 20th-century north-west England that isn’t faintly hilarious in print, and I would not swap a single, solitary second.” Chippy teas, gas fires, formidable older female relatives, Saturday morning telly, sliced bread, pyjamas, pebble dash, margarine and wind-whipped beaches smelling of vinegar are everywhere in this book. Because, of course, to talk about comfort food is so often to talk about childhood, home, family and formative experiences. It is no surprise that so many people, when asked to produce an item of comfort food for the show, reach back to a recipe of their mother’s, something made by their gran, or the flavours associated with sitting with their dad in the pub. Now that Dent makes her living as a restaurant critic and television personality, firmly ensconced in the London liberal elite, all this might feel a bit put on, except that her affection is tangible, her humour tweezer-sharp and the writing as strong as a Christmas stilton. If you are a sweet comfort eater, susceptible to the siren song of malted milk biscuits, Angel Delight, rice pudding or golden syrup, you may find Comfort Eating unfairly weighted towards the savoury. But this is Dent’s book and she has dominion. The main chapters concern cheese, butter, pasta, bread and potatoes, to which she ascribes a God-like status. In fact, in a quintessential Dent sentence, she writes: “Yes, suffering is a natural part of our earthly existence, and everything we love is fragile, but potatoes make all this tolerable.” This is a book that’s not just about comfort but also sadness, suffering and grief; the first series of Comfort Food was recorded just after Dent had nursed her mother during the last weeks of her life, and there is a tinge of heartache to much of what’s described here. All of which makes for a particular kind of slightly mournful, slightly camp, slightly wistful philosophy, typified by statements such as: “Life is impermanent, and everything changes. I love tinned pasta because I like to cling to the small things that are constant.” Have I made a single recipe from the book? No (and there are only six). But halfway through reading it, in the grips of a lung infection and the mournful last days of summer, I did find myself thinking about boiled eggs and Marmite toast in a way that felt almost metaphysical. Comfort Eating by Grace Dent is published by Guardian Faber (£20). To support the Guardian and the Observer buy a copy at guardianbookshop.com. Delivery charges may apply.