The reasons to avoid ultraprocessed foods just keep coming. The largest review of evidence to date, published earlier this year in the British Medical Journal, highlighted 32 ways in which UPFs are doing us dirty, from obesity and heart disease to type 2 diabetes and cancer. As Dr Chris van Tulleken, one of the world’s leading experts on UPFs, put it at the time, an “enormous number of independent studies … clearly link a diet high in UPFs to multiple damaging health outcomes, including early death”.

And yet still we buy them. In the UK and US, they now account for more than half of the average diet.

That’s the bad news. The good news is, you can make your own, healthier versions of many so-called “convenience” foods – and so easily you only need the sketchiest of recipes. Here, then, is how to replace everything from flavoured instant noodles to fizzy drinks.

Snacks, biscuits and cereals

I’ve grouped these together because, with oats, it’s only baby steps between making muesli, granola, granola bars, flapjacks and cookies.

For muesli, just mix rolled oats – or any other rolled or puffed grains – with the dried fruit and nuts of your choice, chopped up. Add seeds, wheat bran and spices to taste. Make it fancy with chopped-up chocolate and cocoa powder. Sweeten with sugar if you want to. And store in an airtight container.

To make the above into granola, keep the dry fruit aside and add it when everything else is cooked (so it doesn’t burn). Combine the grains and nuts with a half-and-half mix of oil and a sweetener (honey, maple or other syrup) to a ratio of 5-7 parts dry to 1 part wet, by volume. Spread over a lined baking tray and bake at a low temperature until toasted. If you want it loose, don’t press down too tight; for big chunks, do.

To turn that into granola bars, cookbook author Emma Christensen uses brown rice syrup at a ratio of 4 cups of granola mix to 1/2 cup syrup. She adds in a few optional tbsp of nut butter for firmer bars. (The Minimalist Baker makes a no-bake bar, mixing oats with chopped up dates and toasted nuts, and a melted mix of nut butter and agave or maple syrup. Press into a lined tray and refrigerate till firm, then slice.)

Flapjacks are essentially the same, but you mix the dry ingredients (plain oats if you’re a purist, everything if you’re not) with a combo of melted butter, sugar and golden syrup. The simplest ratio here is 3 parts oats, 2 parts butter, 1 part sugar (by weight), with 1 tbsp golden syrup per 100g oats. Bake at 180C/160C fan. For both bars and flapjack, the final degree of chewiness or crunch depends on the baking time – just remember they’ll harden as they cool, so don’t overbake.

For oat biscuits – Hobnobs, basically – you ramp up the sugar and butter content, and add flour (1 part of all four) with a little baking soda, a little golden syrup and a pinch of salt. Mix, make balls, flatten on a baking tray and bake for 15 minutes until golden.

Irish baker Gemma Stafford highlights the beauty of what she calls 3-2-1 recipes: 3 parts flour to 2 parts butter and 1 part sugar by weight. Cream the sugar and butter, then mix in the flour until just combined, roll into a log, cut into discs and bake until golden at 180C/160C fan. Her other three-ingredient cookies include 1 cup each of sugar and peanut butter mixed with an egg, or 2 bananas mixed with 1 3/4 cup of oats and a big handful of chocolate chips. Roll into small balls, flatten with a fork and bake at 180C/160C fan for 15-20 mins.

Instant noodles

So long as you have some homemade chicken stock in the freezer, you can make these really quickly. Defrost a portion of stock and bring to a simmer, then flavour it with soy sauce or miso. Cook the noodles according to the packet instructions, drain and add to the stock, then top with a permutation of finely chopped spring onion, half a soft-boiled egg, blanched and chopped greens, a nori sheet cut into thin pieces and some aromatics (toasted sesame seeds, chilli flakes, citrus zest …). If you have any actual chicken meat, you can slice it thinly and cook it quickly in the stock before adding the noodles.

White sliced bread

If you have an oven, a cast-iron casserole with a lid and lots of time, make US baker Jim Lahey’s no-knead loaf. You’ll find a video on YouTube but the kitchen chemist Kenji Lopez-Alt has broken it down into a ratio, which is how professional bakers usually think about breadmaking. Whisk together in a bowl 100 parts flour, 1.5 parts salt and 1 part instant yeast, then add 70 parts water (all by weight) and mix. Cover the bowl with clingfilm or a cloth, then leave at room temperature for 18 hours. (Lopez-Alt puts it in the fridge for three days.) Then turn it out, shape it into a loaf and place it in a cloth-lined bowl or basket for another couple of hours. Heat your lidded casserole in the oven at 230-245C (no fan: most breadmakers suggest not using the fan setting, to preserve the steam you need in the first 3o mins) for half an hour, then gently transfer the dough to the casserole (don’t burn yourself), snip the dome to allow the loaf to expand, put a tray of water at the bottom of the oven (steaming will make the crumb springier) and bake, with the lid on, for half an hour. Then remove the lid, turn down the temperature slightly, and bake for another half hour. If you struggle with the slicing process once the bread has cooled, the secret is a sharp serrated knife and a firm grip.

If you don’t have an oven, make South African baker Noji Gaylard’s steamed loaf: here, the ratio is 500 parts plain flour, 3 parts salt, 12 parts sugar, 1.5 parts instant yeast and 250 parts water. Mix it all vigorously in a bowl with a wooden spoon, cover and rest for an hour, then repeat, resting for half an hour. Pour into a buttered bowl, place in a large lidded pot and add boiling water to halfway up the side of your bread bowl. Steam for two hours or so, until a knife stuck into the centre comes out clean.

If you have no time for all this, make flatbreads: shake some flour into a bowl, add a pinch of salt and a glug of oil if you have some, and some water and mix by hand until smooth. Dan Lepard uses a ratio of 250 parts flour to 150 parts water, but I just eyeball it. Rest it if you have 30 minutes to spare; otherwise shape right away into small balls, roll out as thin as you can and dry fry one after the other on a piping hot heavy-based pan, flipping when you get bubbles.

From there you can try sweet potato, spiced yoghurt, spring onion and garlic and gluten-free options such as rice flour (chawal ki roti), mashed potato or chickpea (farinata).

Fizzy drinks

The easiest way to get a soda fix at home is to flavour sparkling water with fruit juice, aromatics, cordial, honey, maple syrup, jam or any combination thereof. To make your own flavoured sugar syrup, slowly dissolve over a gentle heat 1 to 2 parts sugar in 1 part water (by weight), add whatever fruit, fresh herbs or spices you fancy and simmer for 5-10 minutes. Then strain and bottle in a sterilised jar and use as a cordial.

For a more robust carbonated drink, how about ginger beer, which requires a kind of fermentation culture or “scoby”. To make a ginger bug, as it’s called, combine a piece of fresh ginger, peeled and grated, with 1 tbsp of raw sugar and 2 cups of water in a jar. Cover with a cloth lid and leave in a warm spot for 24 hours, then once a day stir in a tsp of sugar and 1 tsp of grated ginger. Do this until it’s bubbling away on its own – 5-10 days.

Once it’s ready, you can make your ginger beer. In a large jar, combine 1 part starter with 19 parts water, 1.5 parts sugar (by volume), some grated ginger and some fresh lemon juice, cover with a cloth and leave for 8-10 days, until bubbly. As with all fermentation, taste as you go. You can then bottle it in fliptop bottles and leave (cautiously) for a couple of days for extra carbonation, or drink as it is.

Dairy-free milks and cheeses

If you don’t already have a blender, you’ll need one to make your own nut and grain milks and butters. They’re not cheap – but then neither are all the vegan UPF-rich ready-to-gos, cumulatively.

So, to make a milk-like drink, blend with water the grain or nut in question. For oats, a good ratio, by volume, is 1 part oats to 4 parts water; for almonds, 1 part to 5 parts water.

You can sweeten with dates, syrups or vanilla essence and add some salt to balance the sweetness out, but you really don’t need to. Just strain through a muslin and use.

For vegan cheeses, there are lots of complicated ideas, where, yes, you would do best to follow the recipe, but I’d say, learn the basic methods, then experiment yourself. My best tip is that nutritional yeast is your friend. I’m not a vegan, but if I have cashews, I’ll soak them for a while, till soft, then blend them with nutritional yeast, garlic, soy or tamari, some kind of spice or chilli flakes and lemon juice – tasting as I go. I’ll use this as a spread or a dip, or to coat curly kale pieces which I will then slowly dehydrate at a low heat in the oven until crispy. Even my father, a dedicated anti-healthy eater, can’t get enough of them.

Flavoured yoghurt

On the one hand, all you need to flavour yoghurt is jam. On the other, there are plenty of other things you can do to elevate your yoghurt. Straining any plain runny yoghurt will make it creamy and thicker (and give you whey with which to bake). You can then flavour it with different sugars, jam, honey, syrup, nut butters, tahini, stewed fruit and the like. Whip or blend it to achieve a texture you like better. Add in fresh fruits, seeds, nuts, chocolate bits, the granola you just made, cake crumbs, meringue crumbs, toasted bread crumbs, toasted grains … Go wild. Be free.

Chicken nuggets

Some analyses of fast-food outlet nuggets have found them to contain less than 20% actual chicken meat, with the remainder mostly fat, some bone and then tendons, ligaments, blood and guts. Yet at their most basic, homemade nuggets are just bite-size pieces of chicken breast seasoned, floured, egged and breadcrumbed, then deep-fried, baked or air-fried. Where you take them flavour-wise is up to you – to the flour dredge, you can add spices, pepper flakes or dried herbs. You can marinade the chicken before you dredge it. You can add spices and aromatics to the breadcrumb mix. You can also mince the chicken and add aromatics right off the bat, achieving a smoother texture and a more flavoured meat.