How 50 years of processed foods have harmed us
Processed foods have infiltrated every aspect of our diets. What began as a promise of convenience has now become one of the primary drivers of chronic disease. From pre-packaged snacks, and fizzy drinks to ready meals, breads and sugary cereals, ultra-processed foods (UPFs) are everywhere. In fact, in the UK alone, UPFs make up over 57% of daily calorie intake for adults and an alarming 66% for adolescents and young children. This is no longer a dietary choice but a societal norm—and it’s costing us dearly.
It’s hard to believe how much our diets have changed in just half a century. Fifty years ago, most meals were cooked at home using fresh, local ingredients. Bread came from the local baker, milk was delivered to your doorstep, and vegetables were often grown in the back garden. Now, our supermarkets are filled with products that bear little resemblance to real food.
One of the most shocking aspects of modern food is its nutritional decline. Studies have shown that the nutrient content of fruits and vegetables has decreased dramatically over the past 50–70 years. This loss of nutrients isn’t just due to processing; it’s also a result of over-farming and soil depletion. Modern agriculture prioritises yield and appearance over nutritional quality, leaving us with beautiful but nutritionally empty foods. We have also seen changes in crop varieties, including increased use in genetically modified foods. When we then add processing into this, it is little wonder we are seeing patients who are obese but also with significant nutritional deficiencies.
Part of this journey included the low-fat revolution, which began in 1977. We were advised to avoid fat, and, in return, we would all be healthy, free from heart attacks, and slim. The ironic aspect is that we were actually all thin in the 1970s and, since then, we have witnessed the exact opposite of what was promised. Obesity has skyrocketed, with a significant increase starting at the time when we were all monitoring our fat intake, switching from whole milk to skimmed milk and discarding our butter in favour of processed margarine.
The food industry adopted our health message and stepped in, removing all fat from our food and often replacing it with sugars, emulsifiers, and flavourings to enhance palatability. Their profits surged while our waistlines expanded and our health deteriorated. In our quest for calorie counting, we have encountered a rise in Frankenstein foods, all claiming to be low-calorie and low-fat, therefore healthy. Ninety-nine-calorie bars ensure you can eat your cake, but you need a chemistry degree to decipher the ingredients.
The processing of our food is one of our biggest worries and something that people are not always aware of. I have yet to encounter a patient who has not attempted to improve their diet prior to visiting me, but the problem is that we are obtaining our food and health information from the food industry. They are not doctors or nutritionists but businesses that are ultimately there to make a profit and increase sales. Nearly everyone will say no when I ask if they consume any ultra-processed foods. We perceive ultra-processed foods as the most awful junk foods, but they are often shocked when I point out our really common foods, including those marketed as ‘healthy’. But these foods are full of ultra-processed elements.
One of the most commonly used in our food is emulsifiers. Emulsifiers are additives that help mix ingredients that wouldn’t naturally combine, such as oil and water. They’re a key component of many processed foods, ensuring a smooth texture and stable consistency. For instance, they:
- Prevent oils from separating in mayonnaise or salad dressings.
- Stop ice cream from forming large ice crystals, keeping it creamy.
- Prolong the shelf life of supermarket bread by stabilising the dough.
In the UK, emulsifiers are present in a wide range of everyday foods, including:
- Pre-packaged bread and baked goods.
- Processed meats and sausages.
- Sauces and dressings.
- Sweets, chocolate, and ice cream.
While they may seem harmless, emulsifiers can wreak havoc on our health, particularly when consumed as part of a diet already high in UPFs. Combine this with our heavy use of seed oils and we are seeing big changes to our overall health. The most common issues are:
Impact on our gut health - Studies have shown that emulsifiers like polysorbate 80 and carboxymethylcellulose disrupt the gut microbiome, reducing the diversity of beneficial bacteria. Seed oils also contribute to inflammation in the gut lining. The two combined can lead to intestinal inflammation and a condition known as “leaky gut,” where the intestinal lining becomes permeable, allowing harmful substances to enter the bloodstream.
In my clinic, I have observed a significant increase in cases of IBS, bloating, and gut imbalances. Many of these issues can be traced back to diets high in processed foods laden with emulsifiers and seed oils, compounded by our environment, medication, diet and lifestyle. The gut is critical to overall health, influencing everything from immunity to mental well-being. When this delicate system is compromised, the effects ripple through the entire body.
Chronic inflammation - Emulsifiers have been linked to increased inflammation, a key driver of many chronic diseases, including obesity, type 2 diabetes, and heart disease. By disrupting the gut barrier and triggering immune responses, emulsifiers contribute to a cycle of low-grade, chronic inflammation that silently damages the body over time.
Furthermore, it is necessary to examine the effect of seed oils on inflammation. They are high in omega-6, which, although essential in small amounts, can be harmful when consumed in excess. Indeed, we do take this in excess in our Western diets! Another issue with seed oils is the processing, which transforms a relatively innocuous oil into a very different chemical. The industrial methods involved use high heat and often chemical solvents, which generate free radicals and aldehydes, contributing to oxidative stress and inflammation. Some seed oils are partially hydrogenated to improve shelf stability, producing trans fats. Even trace amounts of trans fats are highly inflammatory and have been linked to heart disease, diabetes, and other chronic conditions.
Food manufacturers also rely on additives to compensate for the lack of natural flavour and shelf stability. Artificial sweeteners, preservatives, and flavourings are now staples in most processed foods, all of which have their own impact on our health. When assessing the safety of individual ingredients in processed foods, regulators typically evaluate each additive or chemical in isolation. However, this approach overlooks the “cocktail effect”—the cumulative impact of consuming multiple additives, preservatives, and other chemicals in combination. In processed foods, this means a single meal could contain a mix of artificial sweeteners, emulsifiers, preservatives, colourings, and stabilisers, each tested individually but rarely considered as part of a broader chemical load.
The cocktail effect extends beyond food to include exposures in our environment, homes, and personal care products. Chemicals from cleaning products, plastics, air pollution, and even water supplies add to our daily chemical burden. While each substance may fall within “acceptable” safety limits on its own, their combined effects can amplify health risks. For instance, emulsifiers in food might disrupt the gut barrier, while exposure to environmental toxins could further strain the immune system, creating a perfect storm for inflammation, hormone disruption, or even carcinogenic activity. The reality is that we live in a world of cumulative exposures, and addressing this requires a more holistic view of how these factors interact and affect our health over time.
Fifty years ago, bread was made with flour, water, yeast, and salt—ingredients you could find in any home kitchen. Today, supermarket loaves often contain over 10 additives, including emulsifiers like mono- and diglycerides of fatty acids, designed to keep the bread soft and fluffy for weeks. We need a chemistry degree to understand the food listed on our food labels. I love the quote ‘Man is clever enough to make his own food, but stupid enough to eat it’. When we look at some of the ‘foods’ in our supermarket, we can see the truth in this statement.
Processed foods are more than just “empty calories.” They actively harm our health. The link between UPFs and chronic diseases like obesity, type 2 diabetes, and heart disease is undeniable. A 2019 study in The BMJ found that for every 10% increase in UPF consumption, there was a corresponding 12% increase in cancer risk. Similarly, diets high in processed foods are a leading cause of the obesity epidemic, with nearly 28% of UK adults classified as obese.
UPFs also take a toll on our mental well-being. Processed diets disrupt the gut-brain axis, reducing the diversity of beneficial gut bacteria and impairing the production of neurotransmitters like serotonin. Research has linked high UPF intake to a 22% higher risk of depression and a 50% greater risk of anxiety.
As you may have read in our previous article on emotional eating, processed foods are designed to keep you coming back for more. The combination of sugar, salt, and fat stimulates the brain’s reward system, much like addictive substances do. This is why stopping at one crisp or biscuit is nearly impossible—they’re engineered to override your natural satiety signals.
World health
It is really interesting when we look around the world. You may be surprised to hear that many illnesses common in Western countries are virtually unheard of in regions that stick to traditional diets. If you want proof that food is the foundation of health, look no further than the world’s “Blue Zones”—regions where people live significantly longer, healthier lives.
Okinawa, Japan - Known for its high concentration of centenarians, Okinawa’s traditional diet includes sweet potatoes, seaweed, tofu, and fish. Meals are naturally low in sugar and full of anti-inflammatory nutrients, contributing to the longevity of Okinawans and their low rates of heart disease.
Ikaria, Greece - Dubbed the “island where people forget to die,” Ikaria boasts a diet rich in olive oil, beans, vegetables, and wild herbs. It’s Mediterranean eating at its best, with minimally processed foods and plenty of time spent savouring meals with family.
Nicoya, Costa Rica - Nicoya's diet of corn tortillas, beans, and tropical fruits provides ample fibre and nutrients. Combined with clean, mineral-rich water, this simple diet supports strong bones, good digestion, and a long life.
Other examples:
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Rural African communities, where diets are based on whole grains, vegetables, and lean proteins, have far lower rates of heart disease than the UK.
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Indigenous populations in the Amazon, who eat diets rich in natural carbohydrates and proteins, have minimal rates of obesity or diabetes.
- Conditions like Crohn’s disease and ulcerative colitis are rare in parts of India and Japan, where diets are low in processed foods and high in anti-inflammatory spices and whole foods.
Sadly, these countries are starting to see more Western food pouring into their countries, and this is having a detrimental impact on these statistics.
The power of real food
As a nutritionist, I see firsthand the damage caused by ultra-processed diets. Clients come to me with a host of issues—chronic fatigue, IBS, hormonal imbalances, inflammation, migraines, autoimmune conditions, and, more often than not, their diet is a significant culprit.
One client, a middle-aged man, consumed several ready meals and sugary snacks daily. He had no interest in food or cooking but ate out of necessity. He had a range of health issues, low energy, poor sleep and poor mental health. After just one month of cleaning his diet and ensuring his nutrients were at optimal levels, his energy levels skyrocketed, and his sleep improved dramatically.
Another client, a mother of two, struggled with hormone imbalance, weight gain, brain fog and mood swings. Her diet was full of “healthy” processed, low-fat/low calorie foods and she was really trying hard to buy what she thought was healthy. By switching to natural, nutrient-dense foods, focusing on high protein and low sugar, her hormones started to balance, weight started to shift, and she regained mental clarity.
The transformations I witness when people return to real foods is powerful, but also shows how far we have come away from a healthy way of eating. When you remove artificial ingredients and focus on real food, the body responds. Energy returns, digestion improves, and chronic symptoms begin to fade. It is amazing to see and makes you want to sing this from the rooftops.
How to break free from processed foods
The good news is that small changes can lead to significant improvements. Here are some actionable steps to get started:
- Reclaim your kitchen - Cooking from scratch doesn’t have to be complicated. Simple meals can be just as quick as heating up a ready meal.
- Choose whole foods - Shop for foods with as few ingredients as possible. Fresh fruits, vegetables, whole grains, and unprocessed meats should form the foundation of your diet.
- Plan ahead - Meal prep can save you time and reduce the temptation to grab convenience foods. Spend an hour on Sundays chopping vegetables or cooking grains for the week ahead.
- Read labels - If you do buy packaged foods, look for short ingredient lists with no unrecognisable additives.
It’s easy to feel discouraged when you look at the state of our food system, but there’s hope. Consumer demand is already driving changes, with more brands offering minimally processed options. Governments can also play a role by subsidising healthy foods and imposing stricter regulations on additives. I am a huge advocate of education and something I feel is missing. I have worked with hundreds of schools and children are so interested in food and cooking, but the problem lies at home. Parents are too busy to home cook, or they may not have the skills to do so. If they do create their own meals, children are no longer in the kitchen with their parents when they are cooking. It is interesting to note in the 1940’s, when we were faced with significant food shortages, the government implemented extensive public education campaigns to ensure the population maintained good nutrition. Despite the war, during this time, infant mortality declined, and life expectancy increased, indicating better overall health. The wartime diet, though born out of necessity, highlighted the benefits of balanced nutrition and equitable food distribution. The government’s proactive approach in educating the public played a crucial role in maintaining the nation’s health during challenging times.
The real fad diet isn’t things like keto or paleo—it’s the diet of ultra-processed foods that has taken over our plates. But we have the power to change that. By choosing natural, whole foods, we can reclaim our health, nourish our families, and rediscover the joy of eating. Let’s leave the convenience of UPFs behind and embrace the nourishment of real food. Your body, mind, and future self will thank you.
Resources
- Ultra-Processed Food Exposure and Adverse Health Outcomes (The BMJ)
- How Bad Are Ultra-Processed Foods for Your Health? (British Heart Foundation)
- https://www.cam.ac.uk/research/news/ultra-processed-food-makes-up-almost-two-thirds-of-calorie-intake-of-uk-adolescents
- Ultra Processed People, by Chris van Tulleken.
By Sarah Flower, Nutritionist.
