The most harmful foods you should never eat - 6 foods to eat instead

Episode Overview

• Navigating the Modern Supermarket: Produced by ZOE and hosted by co-founder Jonathan Wolf, this episode features King’s College London professors Tim Spector (ZOE co-founder and author of Ferment) and Sarah Berry (ZOE Chief Scientist) discussing how consumers can navigate grocery stores stocked with 30,000 to 50,000 items—where heavily processed foods are about 55% cheaper than minimally processed options.
• Deconstructing Front-of-Pack Marketing: The scientists explain why front-of-pack health claims like "low fat," "sugar-free," "gluten-free," and "high protein" should be treated as warning signs of heavy processing rather than markers of health.
• Six Rules for the Grocery Aisle: The conversation is structured around six practical rules: checking for hidden ingredients, not fearing fats, rethinking snacks, prioritizing dietary staples, spotting fermented food deceptions, and buying more plants.
• Real-Life Nutrition and Disclosures: Alongside clinical research, the guests share candid personal habits—such as Sarah Berry craving white bread with butter and bacon when hungover, buying sugary Cheerios when overwhelmed in the cereal aisle in the past, her 14-year-old son being brainwashed by TikTok into buying junk high-protein bars, and relying on ZOE products to hit 30 plants a week while working two jobs (including a disclosed self-sponsorship and mid-roll ad for the ZOE Gut Health Bar, which provides 7g of plant protein, 8g of fiber, and 12 to 13 plants).

Key Concepts

• Choice Overload in the Grocery Store: Whereas 70 to 100 years ago people simply ate what was available in their house or village, modern supermarkets carry 30,000 to 50,000 items. Psychologists note that nearly infinite choice overwhelms consumers, causing them to make poor decisions and default to the exact same shopping trolley habits.
• The "Low-Fat" and "Sugar-Free" Trap: Evidence from randomized controlled trials is clear that choosing low-fat over full-fat foods does not lead to weight reduction, a reality reflected in the latest US dietary guidelines (though UK and European guidelines lag behind). When manufacturers strip fat out of food, they typically replace it with blood-sugar-spiking starches and sugars. Similarly, swapping a full-sugar Coke for a no-sugar version saves about 130 calories but introduces artificial sweeteners like acesulfame potassium (Ace-K), aspartame, saccharin, or sucralose, which Tim Spector notes may have a detrimental, negative effect on gut microbes.
• The "Gluten-Free" and "High-Protein" Marketing Halo: Only 1% of the population has celiac disease and possibly another 1% has a gluten intolerance; for everyone else, "gluten-free" labels usually mean the food has undergone extra processing (with the exception of naturally gluten-free lentil or chickpea pastas). Likewise, while 90% of people are not protein deficient, surveys and ZOE studies show around 70% of consumers view any food with a "protein" sticker as healthy—allowing manufacturers to double sales by adding cheap dairy waste (whey protein) to ultra-processed foods.
• Nutrient Profiles vs. Ingredient Lists: Two foods can look nearly identical on their back-of-pack nutrition tables (calories, fat, fiber, protein, salt, sugar) while being vastly different in quality. For example, Kettle Crisps contain only potatoes, sunflower or rapeseed oil, and salt, whereas Monster Munch uses reconstituted starches and most Pringles brands contain over 30 ingredients. Furthermore, many granolas contain numerous additives where scientists do not yet know how they impact the gut microbiome and overall health, and children's cereals like Cheerios or Rainbows are around 30% sugar or more.
• Food Matrix and Fat Quality: Not all saturated fats act the same way in the body. While Sarah Berry buys lower-fat (5% or 2%) minced red meat because its saturated fat is unhealthy, the saturated fat in yogurt is "fermented fat" and is not harmful. Epidemiological evidence also shows that cheese is not harmful to the heart and is possibly beneficial (whether due to fermentation or another mechanism). Similarly, olive oil is about 13% saturated fat and triggers a "big red" traffic light label for total fat alongside nuts and seeds, yet remains incredibly healthy due to its fat profile and bioactive polyphenols.
• The Power of Snacks and Daily Staples: In the US and UK, 20% to 25% of calories come from snacks. A 6-week King's College London clinical trial led by Sarah Berry found that getting 20% of calories from nuts instead of typical US/UK snacks improved blood cholesterol and blood vessel function to a degree equating to a 30% reduction in cardiovascular disease risk. Upgrading daily staples (like bread, rice, and pasta) also yields massive returns: average UK/US whole grain intake is about 16 grams a day, and increasing this to 75 grams a day reduces the risk of all-cause mortality, type 2 diabetes, and cardiovascular disease by around 10%.
• Fermented Foods and Microbiome Reality: Fermented foods have officially entered the US dietary guidelines. For his book Ferment, Tim Spector tested 70 products and found that even basic Gouda, Cheddar, and processed Philadelphia cream cheese contained 3 species of live microbes (whereas Kraft slices, frozen pizza cheese, and some highly processed vegan cheeses had zero). Supermarket kefirs—though a hybrid of yogurt and kefir rather than made from artisan grains—still contain 3 to 4 times more live microbes than standard yogurt, though manufacturers can legally label "any old rubbish" as kefir just by adding 12 specified microbe cultures.
• Plant Diversity for Gut Health: ZOE science indicates people should aim to eat 30 different plants a week for optimal gut health (compared to the US/UK average of 10 to 12), though Tim Spector notes they do not know if there is an upper limit and are investigating whether higher numbers are even better.

Quotes

• At 0:02:21 - "I think it's being fooled by those labels on the front with ridiculous health claims. High protein, low fat, low sugar, low calorie, they're the things most people get wrong and they get attracted to them." - Tim Spector identifying the single biggest mistake shoppers make in the grocery store.
• At 0:05:06 - "And we know the heavily processed ones tend to be about 55% cheaper than the minimally processed." - Sarah Berry explaining the economic pressures driving consumers toward ultra-processed supermarket items.
• At 0:09:15 - "But the evidence from randomized control trials are really clear that if you're selecting low-fat foods above full-fat foods, it does not result in weight reduction." - Sarah Berry debunking the long-standing myth that buying low-fat products helps with weight loss.
• At 0:18:17 - "And this is a 14-year-old child who is being brainwashed, I don't know by what, TikTok obviously because that's what occupies his brain, into thinking as long as it's got protein on it, it's healthy." - Sarah Berry illustrating how social media and front-of-pack "high protein" marketing deceive consumers.
• At 0:19:15 - "You just add a bit of whey protein, it's a waste product from the dairy industry, you know, it costs nothing, they pour it in there and suddenly they can double their sales. It's a scam, basically." - Tim Spector explaining the economics behind the high-protein ultra-processed food trend.
• At 0:29:31 - "A lot of family doctors will tell people to avoid cheese because it's bad for your heart. All the epidemiology evidence suggests that's not the case and that whether it's the fermentation in it or something else, but it's not harmful for you and possibly beneficial." - Tim Spector challenging outdated medical advice regarding full-fat dairy and heart health.
• At 0:34:20 - "In those consuming the nuts versus those consuming US, UK typical snacks, equated to a 30% reduction in cardiovascular disease." - Sarah Berry sharing the results of her 6-week clinical trial at King's College London on replacing typical snacks with nuts.
• At 0:41:09 - "And it's this ratio between the carbohydrates and the fiber that is the only way I can really sort out a healthy bread from an unhealthy bread. And I'm looking for a ratio that is, you know, as close to five as I can get." - Tim Spector providing a concrete formula for reading nutrition labels in the bread aisle.
• At 0:44:41 - "We would change from our average intake of whole grains being around say 16 grams a day, we could get it up to 75 grams a day. And at that level, you reduce your risk of all-cause mortality, type 2 diabetes, cardiovascular disease by around 10%." - Sarah Berry quantifying the massive health impact of simply swapping white bread, rice, and pasta for whole grain versions.
• At 0:48:11 - "Even something that seems rather highly processed like Philadelphia cream cheese, we got three species of microbe out of it. It was only things like Kraft slices that had absolutely nothing in it." - Tim Spector revealing surprising findings from testing 70 products for live microbes for his book Ferment.

Takeaways

• Inspect the Back of the Pack for Whole Foods, Fiber, and Sugar: Ignore front-of-pack claims and check the ingredient list (which is ordered by weight from largest to smallest) to ensure whole foods are at the very top—such as peanuts being #1 in peanut butter rather than palm oil. On the nutrition table, focus on fiber and added sugar (noting that US labels separate added and intrinsic sugars, while UK labels only list total sugar).
• Choose Cooking Oils Strategically: Do not fear healthy fats, and consider using standard rapeseed (canola) oil for high-heat cooking; because heating extra virgin olive oil at high temperatures destroys some of its bioactive polyphenols and it is expensive, rapeseed oil offers an affordable, neutral-tasting, heat-stable alternative rich in mono- and polyunsaturated fats.
• Use the 5:1 Carb-to-Fiber Rule for Bread: Bypass deceptive "granary," "multigrain," or brown-dyed loaves made via the rapid chemical Chorleywood process (which uses glues, emulsifiers, preservatives, and anti-stick chemicals). Instead, divide total carbohydrates by fiber on the nutrition label and buy bread with a ratio as close to 5:1 as possible.
• Upgrade Your Daily Grains: Boost your daily whole grain intake by 50 to 60 grams simply by swapping white bread for whole grain bread (adds ~20g) and white rice and pasta for whole grain versions (adds ~10g each). If you dislike brown rice, swap white rice for high-fiber, high-protein alternatives like bulgur wheat or quinoa.
• Buy Unflavored Kefir and Check Kombucha for Sediment: When buying fermented dairy, choose plain kefir and avoid fruit-flavored or sweetened versions, as Tim Spector notes it is unknown how those additions affect the live microbes. When buying kombucha (which typically has a fifth of the sugar of a Coca-Cola), look for visible sediment at the bottom of the bottle to ensure it is genuinely live rather than just flavored water with added cultures.
• Build a "Diversity Jar" and Stock Underrated Plants: To easily work toward 30 plants a week, mix a bag of mixed seeds and a bag of mixed nuts into a single jar to get about 10 plants in one scoop, and remember that a teaspoon of spice counts as a plant. Prioritize Sarah Berry's top "superfood"—mixed nuts—for snacking, and add Tim Spector's top cost-effective plant, beetroot, to lower blood pressure and support heart health.