And there are reasons we shouldn’t write off UPFs altogether. They can make food last longer and taste better, as well as being more convenient. The problems lie in how much we’re eating (they make up 60% of the average diet in the UK), as they are often low in nutrients; high in sugar, fat and salt; and are so tasty that they encourage us to overeat, she explains.

“They are not whole foods, so essentially, part of the digestion has already been done for us,” she explains. Think of super-soft supermarket bread compared to a more rustic, homemade option; or a packet of crisps that dissolves in our mouth compared to potatoes. “It’s very quick and easy to eat them, which means we absorb lots of calories very quickly,” she says.

Our fridges are particularly vulnerable to becoming full of ultra-processed foods. Here, Lambert shares the staple foods she always has in her fridge, including the UPFs that make the cut – and those she’d never buy.

Cheese

Lambert keeps her fridge well stocked with an array of cheeses, including the classic cheddar, but also mozzarella, blue, brie and even Babybel.

“Most days, I’ll have a small amount of these stronger cheeses,” she says. “They’re so flavoursome and go well with plant-based dishes. I even put a little blue cheese into my homemade burritos, curries and pastas.”

While a Babybel is ultra-processed, that doesn’t make it a bad choice, Lambert notes. “It’s not full of a load of additives, it’s just pretty much cheese, give or take,” she says. “I give my children a Babybel – they travel well in lunch boxes and it’s a far superior choice to a chocolate bar or a fruit yoghurt.”

She cautions that, because of the high calorie and saturated fat content in cheese, it’s important to learn what the correct portion size is (30g, or around a small matchbox-sized piece for adults, and around half of that for children). “Definitely measure out a portion once and then you know what you’re doing.”

Dark chocolate

“Nearly every day as a family, we all have a bit of dark chocolate,” Lambert says. “It contains fewer ingredients than milk, there’s less sugar, and you don’t have all the extra additives and stabilisers. You’ve just got the pure cocoa bean.”

“Dark chocolate also contains fibre and amazing antioxidants called flavanols that research has shown to benefit us – it’s linked to better blood pressure,” Lambert adds.

“I will sometimes have a cube of 75% chocolate in the morning after I finish my breakfast, and I find it just means I’m not craving anything else.”

Lambert tends to buy Ombar, Lindt, Hotel Chocolat or Green & Black’s dark chocolate. “I look at it as a benefit to the diet, as long as it’s a minimal sugar variety.”

Berries

“I’m a huge berry fan and have a portion most days,” Lambert says. They contain anthocyanins, a type of antioxidant that give berries their red, blue or purple colour, and have been shown to benefit brain health, she notes.

“When they’re in season, as they are now, I splash out on a punnet because there’s nothing tastier than berries that haven’t needed artificial help to grow,” Lambert says.

“They’re a beautiful tasting fruit that you can put on every dessert, overnight oats, yoghurt and kefir bowls, or have just enjoyed as a snack with some dark chocolate.”

But, for most of the year, Lambert opts for frozen, as they are much cheaper and just as nutritious, and will use them to make jam. “Jam is a food I would never buy,” she says. “It’s very high in sugar, so I would rather make it.” Her recipe, shared in her new book, simply combines frozen berries, chia seeds and honey or maple syrup.

Kefir

Kefir is a weekly staple in Lambert’s fridge. The fermented milk drink is similar to yoghurt but has a runnier texture. You can drink it, add it to smoothies, stir it into dressings or pour it over fruit, cereal or porridge.

“It’s a better choice than nearly every yoghurt you’ll get out there on the shop shelves,” she says. “It contains more live bacteria than a standard Greek yoghurt, which has just bifidobacteria or lactobacillus added in. The extra strains are beneficial for gut health.”

“I go for the natural one, so it’s just the flavour of the cow’s milk,” says Lambert, who opts for the kefir made by Biotiful, Yeo Valley or The Collective. Buying for the plain flavour means it shouldn’t contain artificial sweeteners or flavourings, and you can add your own fruit for extra flavour.

Pizza

“We do pizza night every Friday because I’m tired, it’s the end of the week and I don’t really want to cook,” Lambert says. “The difference is, I know how to spot a healthier pizza. Crosta Mollica is an example of pizza that doesn’t contain additives or preservatives.”

Lambert recommends checking the ingredients list and makes her own if there isn’t one like this available. There will often be some additives in shop-bought pizza to stop them from spoiling too quickly, and palm oil might be added to keep the dough soft, she notes.

“I normally get two adult-sized pizzas and serve it in the middle of the table, always alongside crudites – cucumber and pepper with some hummus. I also might add some tinned sweetcorn to the pizza. That’s how we do pizza night.”

Vegetables

“The vegetable drawer is my favourite,” Lambert says. “To create healthy meals, vegetables are essential – they’re rich in vitamins, minerals and unique plant compounds that help protect against disease and support gut health.”

To get more in your diet, Lambert recommends buying seasonally (broad beans, chard, courgette, rocket, spinach and spring onions are all in season in June), as they’re cheaper and more nutritious.

“Try incorporating one new vegetable each week to support your gut microbiome and work toward the goal of eating 30 different plant foods a week,” she says. “A diverse diet rich in plant foods helps feed different types of beneficial gut bacteria, which play a key role in digestion, immunity and even mood regulation.”

Her fridge is filled with tomatoes, peppers, red onion, courgette, sweet potatoes, broccoli, fennel, avocado, garlic and ginger. “Most weeks, I’ll make a large tray bake with vegetables and olive oil, because I can then use the roasted vegetables in meals throughout the week, adding them to a wrap for lunch or curry and stir fry for dinner,” she says. “They set you up for a whole week, and it means I don’t have to cook the vegetables from scratch every mealtime.”

Oat, almond and soya milk

Lambert switched to plant-based milk, mainly oat and almond, a few years ago. “Since my family and I eat a balanced, nutritious diet, we don’t rely on the nutrients found in cow’s milk,” she says. “Fortified plant-based alternatives are a great option for us.”

There has been some backlash against these drinks because they can contain seed oils, Lambert notes. “I’m keen to bust myths that plant milks are bad because of seed oils,” she says. One concern is that an omega-6 fatty acid found in seed oils (linoleic acid) may contribute to inflammation, but experts say the evidence doesn’t support this.

“There are wonderful fortified options, so they still contain vitamins and minerals,” she says. “It is an ultra-processed food and that’s something I’m happy to have.

“Synthetic vitamins will never replace whole food but that’s not really the point. The point is, you still get something from it, just not the whole amount.”

Leftovers

“Like many people, I’m too busy to cook from scratch every day; after a long day at work and with a family to feed, time can be tight,” Lambert says. “That’s why I always aim to cook once and eat twice (or more).”

While it does require a bit of planning, cooking extra portions of a healthy meal to enjoy over the next day or two saves money and makes healthy eating more manageable, she says. “Knowing I have something nutritious and tasty ready to go takes a big chunk of stress out of my evening,” she adds.

“I have a Tupperware of leftover burrito in my fridge at the moment,” Lambert says. It’s made with sweet potato, black beans, onion, peppers and smoked paprika, and she serves it with green leaves and avocado. “I wouldn’t use a store-bought spice mix because they’ve got so much added sugar,” she says. “You can do it yourself cheaper and healthier.”

Tofu

Lambert’s diet is largely plant-based – though the recipes in her new book contain meat – so she eats plenty of plant-based sources of protein, such as tofu. She opts for calcium-set and organic tofu when it’s available, such as Cauldron.

“It is also a good source of protein and iron, and low in saturated fat, so I like cooking this for the children and I,” she says. “One of my go-tos is to slice the tofu, put it on a baking tray with olive oil, a little salt or paprika and roast it. It’s the best snack for movie night.”

She also uses it in her sweet and sour sticky tofu and tofu larb (a Thai salad), both recipes from her new book.

Tempeh

Tempeh is another plant-based protein source and it’s made from fermented soybeans.

“It’s good for your gut health and the texture is really nutty and delicious,” she says. “It’s a really good substitute for meat because, while tofu is more malleable and soft, tempeh has a chew that’s similar to the texture of meat.”

Watermelon

It’s important to get a range of fruit and vegetables in your diet, rather than getting stuck in a rut of eating the same few all the time, Lambert notes.

“This week, I bought watermelon purely because it was on offer and helps to hit our 30 plants a week,” she says. “We had some with our breakfast this morning and it was lovely. Next week, it might be grapes or blackberries.”

Flaxseeds and chia seeds

Large bags of flax and chia seeds take up most of one shelf in Lambert’s fridge and she usually buys Linwoods, Chia Charge or Good4U brands.

“We call them sprinkles in my house,” she says. As well as sprinkling on top of yoghurt and fruit, she also uses them to make her seedy granola.

Sprouts

“I always buy alfalfa sprouts – I’ve been eating them for about 10 years,” Lambert says. These sprouts, which look like cress and taste like radishes, are broccoli plants that are three or four days old. “I sprinkle them on top of meals,” she says.

They offer a hit of sulforaphane (a powerful antioxidant) at much higher levels than found in regular broccoli, Lambert adds.

Matcha

“My fridge is always full of matcha tea because I don’t drink coffee,” Lambert says. She has jars from OMGTea and Casa Cura in her fridge. It comes as a powder, made from finely ground green tea leaves, which is whisked with hot water or milk for a caffeine hit.

“Matcha is having a real moment but I’ve been drinking it for the last decade,” she says. “It’s picked when the leaves are very young, so you’ve got a lot more energy and antioxidant potential compared to drinking old leaf tea, which is what makes matcha so special.”

Energy balls

“I always make energy balls for the kids and I,” Lambert says. She throws nuts, dates, seeds and some zest into a blender, sometimes adding berries or chocolate.

“It is such a good snack when you’re really hungry and go to the fridge,” she says. Her coconut, date and orange energy balls pack 11g fibre and 10g of protein and the recipe is in her new book. They take just 10 minutes to prepare (plus our hour of chill time in the fridge) and last for two weeks.

Apples

Apples are a nutritious go-to snack for Lambert and her children. “They’re full of fibre and great for our gut microbes, especially if you eat the skin,” she notes. Each apple has around 1.8g of fibre, counting towards the 30g we’re supposed to have each day.

“I also grate apples in overnight oats, add them to porridge or kefir bowls, and they make a great crumble when they start to go soft,” she says.

Fage 5% yoghurt

Authentic Greek yoghurt tends to be a superior option compared to low-fat, high-protein or Greek-style yoghurts that may contain added starches, gums, sweeteners or other ultra-processed ingredients, Lambert notes.

“Fage is an example of an authentic Greek yoghurt – this one happens to be my son’s favourite because it’s blue,” she says. It contains a blend of beneficial live active cultures, including L. bulgaricus, S. thermophilus, L. acidophilus, Bifidus, and L. casei, she notes.

“These bacteria contribute to gut health and are considered probiotics, which are microorganisms that can provide health benefits when consumed,” Lambert adds.

Aqua Libra sparkling water

“I have never been a fan of drinks like cola or Fanta, even as a child, but I love sparkling water,” Lambert says. “As a special treat during the hot weather, it has been really nice to reach for one of these when my family and I want a healthy refreshing drink that tastes delicious.”

This brand has no artificial additives or colours and some studies suggest that sparkling water can be more effective than still water in relieving constipation and improving digestion, she adds.

It can also be a good alternative to alcohol, which Lambert only has on special occasions. “I can have just one glass of bubbles or a cocktail and leave it at that,” she says. “Mocktails are also great when you’re out these days.”

Benecol spread

“High cholesterol runs in my family and although Benecol spread is a UPF, I consider small amounts of this a preferable option most of the time over butter for my health,” Lambert says. She mainly has it on bread in the morning for breakfast, often mixed with avocado.

“These spreads contain plant stanols, which help block cholesterol absorption, promoting heart health,” Lambert explains.

Smoked salmon

“Salmon is rich in omega-3 and has such a strong taste, a little goes a long way in recipes,” Lambert says.

It’s a nice treat to pick up when it’s on offer, to have with eggs and homemade bagels, made from just wholemeal self-raising flour and yogurt, she says.

Five things I’ve banned from my fridge

Pork sausages and bacon

Processed meats, such as sausages, are not healthy to consume frequently, Lambert says. The World Health Organisation (WHO) has classified these types of meat as a Group 1 carcinogen, which means they are known to increase the risk of cancer in humans.

Coke

“I don’t like the taste,” Lambert says. “I know I am in the minority but as a mother and nutritionist I think it’s important not to have items like this in the house, they offer no nutritional value and I think it’s very easy for children to get hooked.

“Everyone has to decide for themselves what their compromise is, so I understand for some of my clients they couldn’t live without this drink at home, so we look at other areas of their nutrition – it’s all a balance.”

Ketchup

It’s full of added sugar and unnecessary if you cook a lot of meals at home, Lambert says. She shares her recipe for her homemade version in her new book, which is made from chopped tomatoes, onion, garlic and spices.

“I think it’s one of those items if you’re ordering fast food out and about you go for it, but for my family and I it’s not an everyday item,” she says. “I find in the clinic a lot of households don’t use it, and it ends up sitting past the use-by date in the fridge.”

BBQ sauce

“I might be in the minority, but I’ve never been a big fan of condiments and BBQ sauce is where I personally draw the line,” Lambert says. “I wouldn’t want my children regularly consuming something so high in added sugar, salt and artificial additives.”

“Just two tablespoons of BBQ sauce can contain up to 14 grams of added sugar more than half the recommended daily limit for children,” she notes. However, not all condiments are equal. Mustard is generally a healthier option and can be useful in small amounts to add flavour to recipes.

Energy drinks

“I’m fully aware of the place they can hold for some, but the reality is for my household they are unnecessary, full of additives, colourings and sugar or sweeteners,” Lambert says.

Instead, she recommends getting more energy from a balanced diet with snacks.

“Personally, with two children in my house under the age of five, it would be dangerous as they contain high levels of caffeine and sugar, which can lead to various health problems.

“The effects can range from mild, such as increased anxiety, to more serious, including heart palpitations and even seizures.”