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There's a BIG Reason to Avoid Ultra-Processed Food

There's a BIG Reason to Avoid Ultra-Processed Food

Eating too many instant foods is associated with a higher risk of cancer.

You already know it’s not healthy to eat microwave meals, fast-food nuggets or bags of chips—but according to a new study, a diet that includes these things even just a few times a week is associated with a major health drawback.

Research from The BMJ has found a correlation between those who eat ultra-processed foods and an increased risk of cancer.

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Ultra-processed foods are products that use additives such as sweeteners, emulsifiers, preservatives, and artificial colors and flavors. They’re often high in calories, and high in sugar, fat, and sodium.

One way to easily spot ultra-processed foods? Take a look at the nutrition label—if you spot a laundry list of unpronounceable or unrecognizable ingredients, there’s a good chance it’s ultra-processed.

According to the study, ultra-processed foods include things like cakes, chicken nuggets, sodas, processed meat, instant noodles, and chocolate bars. But it also includes mass-produced bread, and "frozen or shelf-stable ready meals." So even if those meals claim to be healthy, they may not be (here are 4 "healthy" buzzwords to beware of when shopping).

Researchers observed the diets of over 100,000 adults who used a system called NOVA to log their meals. Researchers then catalogued the 3,300 foods subjects ate by how “processed” they were.

The study found that a 10% increase in eating ultra-processed foods was associated with a 12% increased risk of cancer—and an 11% increased risk of breast cancer.

The study says, “Ultra-processed fats and sauces, sugary products, and drinks were associated with an increased risk of overall cancer, and ultra-processed sugary products were associated with risk of breast cancer."

It's important to note that more studies have to be done before anyone can say that eating ultra-processed foods cause cancer. This study just found a correlation. There may be other factors relating to people who eat more ultra-processed foods that negatively affect their health.

The bottom line: A balanced diet rich in whole grains, fruits, and vegetables beats out packaged foods with no nutritional value any day.

4 Foods to Avoid for Better Gut Health & What to Eat Instead

Why should you be concerned about gut health? A healthy gut helps you absorb more nutrients from the food you eat. Yet, a healthy gut does more than that. Research shows that 70% of your immune system lies in your intestinal tract. What’s more, this portion influences the activity of your immune system. Therefore, the health of your gut may play a key role in protecting against infection and in preventing the overreaction of the immune system that triggers chronic inflammation. In addition, some studies link a healthy gut to better weight control and brain health.

Your gut is colonized by trillions of bacteria. Bacteria have the reputation of being harmful because some cause disease, but the bacteria that populate a healthy gut are not only harmless but offer health benefits. For one, they protect against the invasion of harmful bacteria, viruses, and yeast by competing for their resources. When the gut is full of healthful bacteria, there’s less space or resources for bad bacteria to lay down roots.

Each person has a population of bacteria residing in their gut and it’s almost like a unique signature, so much so that it’s come to be called the gut microbiome. What’s more, lifestyle habits and the foods we eat can modify these bacteria and alter their composition for better or worse. This, in turn, can impact health in a positive or negative way. What should you eat and not eat to protect your gut microbiome and keep it healthy? First, let’s look at some foods to avoid.

Ultra-Processed Foods

Did you know processed foods make up more than 60% of the offerings you find at the average supermarket? They’re everywhere and people love them because of their convenience. Yet, more highly processed ones may harm your gut. These foods are high in sugar and some research suggests that sugar may contribute to a less favorable gut microbiome – but there’s another reason.

Most ultra-processed foods contain emulsifiers, food additives that give the product texture and extend the life of the product. Research in mice shows that carboxymethylcellulose and polysorbate 80, two common emulsifiers in processed foods, triggered inflammation, weight gain, and metabolic changes in the mice. Since emulsifiers have detergent-like properties, researchers believe these common additives in foods like ice cream and salad dressings could damage the gut lining and harm the gut-friendly bacteria that live there. One concern is that these changes might increase the risk of colon cancer. Another reason to avoid ultra-processed foods and eat foods in their whole, unaltered state.

Artificial Sweeteners

Artificial sweeteners provide sweetness without supplying significant calories or causing a rise in blood sugar. This makes them popular with diabetics. However, recent studies question whether these sweeteners are safe. In a 2018 study, researchers tested 6 of the most popular artificial sweeteners and their impact on the gut microbiome. They found that even low concentrations of 1 mg/ml of these artificial sweeteners were harmful to the healthy bacteria that reside in the gut.


An occasional glass of wine may not harm you, but excessive use of alcohol could be harmful to your gut. Preliminary research finds that long-term use of alcohol alters the composition of the gut microbiome in people in a way that may trigger inflammation. In fact, this may explain some complications associated with long-term alcohol use, such as liver disease. If you drink alcohol, stick to no more than a single glass of wine daily.

Excessive Amounts of Red Meat

A diet high in red meat can negatively impact your gut microbiome in two ways. For one, the red meat you eat may contain antibiotic residues that harm healthy gut bacteria. Eating an occasional piece of red meat probably won’t have a big impact on your gut microbiome, but eating it every day is a different story. According to the World Health Organization, 80% of the antibiotics purchased are for use in animal agriculture. If antibiotics destroy bacteria when we take them for an infection, why wouldn’t the traces of antibiotics in red meat do the same?

But that’s not the only way a diet heavy in red meat may damage the gut microbiome. Studies show that people who eat a diet high in red meat have higher levels of a chemical called TMAO in their bloodstream. Where does TMAO come from? When bacteria in the gut feed on nutrients in red meat, they produce this chemical. The reason TMAO is so problematic is that it changes the activity of blood-clotting cells called platelets in a way that increases the risk of a blood clot forming in a blood vessel. Interestingly, a red meat diet also makes it harder for the kidneys to flush TMAO out of the body.

Foods that Support Gut Health

Now, you know what to avoid. What should you eat to enhance the health of your gut? Plant-based foods are rich in a type of fiber called prebiotics. Even though we can’t break this fiber down, bacteria can. When they do, they produce short-chain fatty acids that support a healthy gut lining. Some preliminary research suggests that short-chain fatty acids, such as butyric acid, may lower the risk of colon cancer, possibly by reducing inflammation. Some good sources of prebiotic fiber are legumes, asparagus, oats, apples, garlic, onions, leeks, nuts, almonds, flaxseed, and more.

Probiotic foods support gut health in a different way. These foods supply your gut with healthy bacteria. Why not take a supplement? Recent studies question the merits of doing this since supplements contain varying types of bacteria and we don’t yet know which ones are protective. Plus, some probiotic supplements have quality control issues or lack enough bacteria to make a difference. In addition, recent research shows that probiotic supplements are linked with digestive upset in some people. Also, there have been cases of people with weakened immune systems developing severe side effects and infection from taking probiotic supplements. Get your probiotics from food by choosing more prebiotic and probiotic-rich choices. You’ll get the additional benefits these foods offer too!


· Am J Physiol Gastrointest Liver Physiol. 2012 May 1 302(9): G966–G978.

· Food and Nutrition. “Food Additives: Emulsifiers”

· Advances in Nutrition, Volume 10, Issue suppl_1, January 2019, Pages S31–S48.

· Science Daily. “Artificial sweeteners have toxic effects on gut microbes”

· Am J Public Health. 2015 December 105(12): 2409–2410.

· National Center for Complementary and Integrative Medicine. “Probiotics: In Depth”

· Medical News Today. “Red meat raises heart disease risk through gut bacteria”

Common And Uncommon Sense About Ultra Processed Food: Findings From The New Randomized Controlled Trial

But there is new news, or at the very least, there is scientific confirmation of what many people have suspected. There has never been a randomized controlled trial testing the effects of increasing ultra-processed foods on weight loss.

Common sense may dictate that "processed foods are fattening," but how? Are they simply a source of excess calories or are they inherently fattening in some other way as well? For example, it's not unusual at all for people to believe that refined sugar simply turns into body fat (false). Only a controlled study can show a cause-effect relationship between food and fat gain and that's what this was.

First, here's the definition of ultra-processed foods, according to the researchers: "Formulations mostly of cheap industrial sources of dietary energy and nutrients, plus additives, using a series of processes."

Next, here's a quick recap of the study design:

Lead by Kevin Hall, the researchers admitted 10 men and 10 women who were all weight-stable into their inpatient facility at the NIH where they lived for 28 days and everything they did could be controlled and measured. They were assigned randomly to the ultra-processed or unprocessed diet for 2 weeks, and then crossed over to the other diet for 2 weeks.

Each participant in each leg of the study was given three daily meals and was instructed to eat as much or as little of them as they wanted (ad libitum). The meal plans were designed to be matched for calories, energy density, macronutrients, fiber, sugar and sodium.

The results? On the ultra-processed food diets, subjects ate on average, 508 more calories per day. That's an enormous difference.

It shouldn't be a surprise then, that on the ultra-processed diet, subjects gained weight (1.7 lbs in only 2 weeks) and lost weight on the unprocessed diet (2.4 lbs in only 2 weeks).

If someone were tempted to shrug this off as, "Yeah, still just common sense," a key point to remember is that the subjects were not tracking calories or macros. When left to their own devices (in terms of how much they could eat) and only doing one thing different - increasing or decreasing ultra processed foods, fat gain, or fat loss respectively, was the result.

In addition, consider this: why are there still so many diet wars with factions arguing, sometimes aggressively, about whether the ideal weight loss diet is low carbohydrate, keto, paleo, high protein, low fat, vegetarian, vegan and so on?

The question is not whether these diets work - all of them can work, and no single diet is going to be suitable for everyone's preferences and lifestyles. The more important question is why do they work? For some strange reason, there are still large numbers of people who don't believe weight loss is a calorie thing.

Low carb dogma is usually dismissive of the role of calories. Low carb and keto advocates to this day will tell you that obesity is caused by carbs and insulin. But research does not support this hypothesis. It's an excess of calories that leads to fat gain. Ultra processed carbs can simply be a big part of that energy surplus in the average person's diet, and the call to cut carbs is simply one way to reduce calories.

Conversely, advocates of low fat or vegan diets may claim that dietary fat or a high intake of animal products is responsible for fat gain. There are observational studies showing high fat diets correlate to weight gain, yet there is no cause and effect link there either. Ultra processed foods are a delivery vehicle for unhealthy fats, and dietary fats are calorie-dense. But it's possible to lose weight on a high fat diet, just like it is on a high carb diet, if you're in a calorie deficit.

Also somewhat strange if there's no health reason to do so, the "reduce carbs" guideline is often inclusive of non processed carbs like sweet potatoes, brown rice, beans, oatmeal, 100% whole grains, even, believe it or not, fruit.

In a similar fashion, all kinds of specific foods, from wheat to dairy to potatoes and more, have been demonized and implicated in fat gain and obesity by countless popular diets, with no cause and effect evidence. There is typically some kind of nutritional bad guy named, and it's never "too many calories" because that's not sexy enough to sell.

Popular diet recommendations are diverse, but they all share a common piece of advice: avoid or minimize ultra-processed foods.

The scientific evidence points to the fact that obesity and associated diseases like type 2 diabetes have risen in parallel with an increasingly industrial food system and the easy availability of cheap processed food. Combine that with a decline in physical activity and we've got an epidemic.

We're still talking common sense here when we talk about how processed food makes us fatter, we simply now have the first controlled trial confirming it. But there were more "uncommon" findings that popped up in this study as well.

Some previous research theorized that ultra processed foods are hyper-palatable, have "supernormal appetitive properties," or may disrupt gut-brain signaling and influence food reinforcement and overall calorie intake through pathways distinct from energy density or palatability of the food.

As many scientists have suspected, appetite hormones are involved. The high processed food group saw an increase in the hunger hormone ghrelin, while the unprocessed food group saw an increase in the appetite suppressing hormone PYY.

One surprise in the new study was that participants did not rate the ultra-processed foods as being more pleasant or familiar, which means the increased calorie intake and fat gain don't seem to be a reflection of the processed food menu being more delicious.

But if it's not the simple idea that processed foods are tastier and that's why you eat so much more, what is it? One interesting finding was that the subjects ate the food faster.

The meal eating rate for the ultra-processed diet was 17 calories per minute faster. This eating rate was directly correlated to higher total calorie intake. This has been demonstrated in many previous studies which found that a 20% change in eating rate can impact energy intake by 10 to 13%.

Eat slowly is another piece of common sense advice - the kind of thing your mother may have told you. It is unfortunately not common practice since people are often eating processed for speed and convenience in the first place.

An even more notable finding is that the increase in calories in the ultra processed diet came from carbs and fat. In ad libitum conditions, the protein intake stayed remarkably stable. This is confirmation of the protein leverage hypothesis which says our bodies automatically try to keep a constant protein intake, so people eating less protein from ultra-processed foods may be eating more food overall to try to maintain a physiologically adequate protein intake.

Yet one more finding. Remember, this was a metabolic ward study, so calories in and calories out could be directly tracked. The amount of weight gain experienced by eating the processed food correlated highly with the amount of surplus calories consumed. This gives us more confirmation about the role of energy balance in weight gain or loss.

What we have here is a well-controlled study that on the surface only seems to confirm common sense advice about avoiding junk food, but with a closer look, gives deeper insights into the cause of the obesity crisis, helps explain why popular diets really work, and proposes a simple way to help you get lean and stay lean.

Like many pieces of the body transformation puzzle, this is simple stuff, but not easy, especially when you consider how cheap, convenient and ubiquitous junk food is. Be prepared to flex some discipline and put in some effort, because eating for healthy fat loss is not always easy in our modern environment.

Train hard and expect success,

Tom Venuto, author of
Burn the Fat, Feed the Muscle and
(New!) The Ultimate training manual series

PS "Eat less processed food" is sound advice, but it may not be useful enough to stop there. Offering meal planning guidance and more specific strategies on controlling excess calories from processed food will help even more, and that's what we're here for.

To Discuss This study in the Inner Circle Research and Science forum Click Here

Scientific References:

Hall K et al, Ultra-processed diets cause excess calorie intake and weight gain: A one-month inpatient randomized controlled trial of ad libitum food intake, NutriXiv, 11 Feb. 2019. Web.

Copyright Burn The Fat Inner Circle. No reproduction of this article is permitted

2. Refined Sugars

Excess or added (refined) sugar is an close competitor to the above. It comes in many different forms as we’ll see, and we find it in even the most unexpected places.

Furthermore, science conclusively shows that excess sugar is a major driver of type 2 diabetes, heart disease, systemic inflammation, brain deterioration, and a plethora of other health epidemics. This calorie-dense ingredient can be hard to avoid without some basic principles:

  1. Read the ingredients
  2. Avoid processed foods
  3. Don’t buy it!

It’s easy to avoid sugar, you just have to know where it hides. Creating whole food, natural snacks, sauces, dinner recipes and so on is a simple process that can easily be integrated into your lifestyle!

The hardest part for some is “weaning off”. But you’ll always find the effort worth it, freeing yourself from what can truly be called one of the worst ingredients in food.

Your taste buds naturally adapt, and very soon you’ll begin to detect (and love) the subtle flavours and natural sweetness in real foods.

P.S. Take a look at number 7. Artificial Sweeteners for more information on a natural taste bud reset!

Common Sources to Avoid:

  • Granulated or powdered sugar
  • High-fructose corn syrup (HFCS)
  • Ingredients ending in “-ose”:
    • Dextrose
    • Maltose
    • Sucrose
    • Glucose, etc.
    • Breakfast cereals
    • Granola
    • Breakfast bars
    • Snack bars (including “healthy” options)
    • Chips / fries
    • Crisps / potato chips
    • Cooking pastes
    • Stock cubes
    • Sauces (including those in tinned foods, etc.)
    • Spice mixes
    • Condiments
    • Jams and jellies
    • Packet or pot noodles
    • Pasta
    • Rice
    • Soups
    • Microwave meals, etc.

    Healthy Alternatives:

    • Vegetables (Starchy, root, and fibrous vegetables all help to beat cravings and satisfy a well-rounded diet).
    • Fruits
    • Small amounts of honey (unpasteurised or raw is best)
    • Small amounts of black molasses and natural maple syrup
    • Low-GI drinks and beverages:
      • Water
      • Herbal teas
      • Coffee
      • Tea
      • Milk
      • Homemade vegetable juices, smoothies, and shakes
      • Stevia
      • Erythritol
      • Yacon
      • Xylotol
      • Oatmeal
      • Millet
      • Brown Rice
      • Wild Rice
      • Quinoa
      • Farro
      • Pearl Barley
        There are thousands of ways to easily make these delicious at home – including for breakfast. Just take a look at some of my top oatmeal breakfast recipes)!
      • Chicken stock
      • Bone broth (Benefits and Recipe in this Post)
      • Vegetable stock
      • Kombu Dashi
      • Stock cubes (you can freeze stocks and broths like ice cubes)
      • Spices and herbs

      Shelf-stable, processed foods can be less nutritious than others&mdashbut let’s not demonize the whole category

      Real talk: Packaged, processed food has a bad rap in the wellness world. And some of that is justified. Shelf-stable foods&mdashfrozen, canned, and packaged&mdashoften contain more sodium as a preservative. These foods may also contain added sugar, salt, and other fillers.

      But despite the battle of fresh food vs processed food, there’s no reason a person should go out of their way to avoid all canned and packaged goods. Remember, the term “processed food” applies to any food that has changed from its original state. So pasta is technically processed, as are canned beans, and pre-shelled nuts&mdashbut we shouldn’t treat those healthy foods as being the same for your health as an ultra-processed fast food meal. Nor should we demonize foods that make it easier for people to eat, full stop. Especially when they are often, as illustrated above, just as healthy as eating fresh.

      Instead, check the label on the canned, frozen, and other packaged goods you choose, and prioritize products that have little to no added sugar and sodium when possible. If you can&rsquot find a no-salt-added variety, rinse the food well under water, then lay off the salt shaker. If you ultimately go overboard on sodium one day, try to cut back the next. &ldquoThis is not the time to get super nitpicky with yourself,&rdquo says Cording.

      Here are some other smart tips for choosing the healthiest possible processed food:



      While a little bit of beef is OK, according to Helen Kollias, PhD and director of science for Precision Nutrition, more than 18 ounces a week is associated with a higher risk of cancer. Instead, it's best to eat smaller portions of high-quality steak, and pair it with loads of veggies.


      Lamb isn't just red meat, it's also very high in saturated fat. And while most experts agree that saturated fat doesn't have the heart disease risk factors we once believed it did, it one 2015 research review in the journal Medicine linked increased saturated fat intake in postmenopausal women to an increased risk of breast cancer.


      Yep, despite its pale appearance, veal counts as one of your red meat servings. Avoid eating too much of it if you don't want to increase your cancer risk.

      List of Processed Food You Should Avoid

      Here is a list of processed foods to avoid and healthy alternatives for them:

      Processed Foods to Avoid Healthy Alternatives
      Ketchup: Ketchup is not just made with tomatoes it is also loaded with sugar and is a very addictive ingredient. Chutneys: Chutneys are often made with vegetables, dals and other healthy and whole ingredients that are blended into a paste-like texture. This is the perfect replacement for ketchup and has the benefit of coming with a different flavours depending on what you feel like preparing. They can be used in the same way as ketchup and can be used to make sandwiches or as a dip.
      Marinades: It may be easier to pick up packets of readymade marinade masalas for your meats, but these are often loaded with preservatives and other ingredients you should not be consuming in excess of. Make Your Own: It is not very difficult to make your own marinade, even for exotic dishes like chicken tikka masala or butter chicken. Once you have assembled your ingredients, you simply need to blend everything up. There are also many recipes that do not require the use of blending or fancy masala marinades, so you may want to opt for those rather than buying the processed marinade packets.
      Two Minute Noodles: There are many different varieties of processed noodles that come in a packet with sachets of masala mixes and flavourings. These are very bad for health as they contain bad fats, high content of MSG and salt and are made of maida, which is refined flour. Whole Grain Pasta: Since processed noodles are often chosen for their speed and need for fewer dishes and steps, you can opt for cooking your regular noodles in the same way. Choose whole grain pasta noodles and cook it with your broth in a one-pot cooking style. The result will be as comforting and quick as adding vegetables to a two minute noodle packet.
      Breakfast Cereal: While they are marketed as healthy, breakfast cereals are filled with way too much sugar and are bad for your health in the long run. Homemade Cereal Mix: Mix together some whole grains for fibre like oats, bran or quinoa, nuts and dried fruits and maybe even some coconut if you have it. You could even replace your cereal habit by simply having a bowl of yogurt fruit salad, where you chop up some fruits and mix it together with yogurt.
      Margarine: Margarine is processed to taste and look like butter. It is made with vegetable oil, and it goes through the hydrogenation process, which will end up increasing the amount of trans fats. Butter: Use real butter instead, since it is just churned milk cream.
      Fruit Juices: Fruit juices are very bad for health despite how healthy they sound. Packaged fruit juice often has the fibre removed, making the assimilation of sugar faster. Water or Smoothies: Either stick to drinking water to quench your thirst, or if you feel like you need something more in your drink, opt for a smoothie. Choose fruits like berries, pears and don&rsquot forget to add green veggies.
      Salad Dressing: Store-bought salad dressing is full of added chemicals, sugars and unhealthy trans fats. Make Your Own: There are many simple salad dressing recipes that you can find online that make use of healthy ingredients.
      Maida: Avoid anything that contains refined flour since the endosperm of wheat germ and wheat bran is removed during the refining process. This is what makes the grains good for our bodies. Whole Wheat or Multigrain: Whole wheat or multigrain flour is much healthier and provides the health benefits that wheat is known for.
      White Rice: The refining process removes all the important nutrients from the grains of rice, making it high in carbohydrates and starch. Brown Rice: Brown rice contains the bran, germ and endosperm, all of which provide health benefits to the body.
      Processed Meats: Meats like frozen burgers, nuggets, salami, bacon and other meats that are processed are known to increase the risk of colorectal cancer by 18%. Fresh Meat: Consuming fresh meats are a healthier option than adding processed meats to your diet.

      How ultra-processed food took over your shopping basket

      It’s cheap, attractive and convenient, and we eat it every day – it’s difficult not to. But is ultra-processed food making us ill and driving the global obesity crisis?

      Last modified on Fri 6 Mar 2020 12.00 GMT

      N early three decades ago, when I was an overweight teenager, I sometimes ate six pieces of sliced white toast in a row, each one slathered in butter or jam. I remember the spongy texture of the bread as I took it from its plastic bag. No matter how much of this supermarket toast I ate, I hardly felt sated. It was like eating without really eating. Other days, I would buy a box of Crunchy Nut Cornflakes or a tube of Pringles: sour cream and onion flavour stackable snack chips, which were an exciting novelty at the time, having only arrived in the UK in 1991. Although the carton was big enough to feed a crowd, I could demolish most of it by myself in a sitting. Each chip, with its salty and powdery sour cream coating, sent me back for another one. I loved the way the chips – curved like roof tiles – would dissolve slightly on my tongue.

      fter one of these binges – because that is what they were – I would speak to myself with self-loathing. “What is wrong with you?” I would say to the tear-stained face in the mirror. I blamed myself for my lack of self-control. But now, all these years later, having mostly lost my taste for sliced bread, sugary cereals and snack chips, I feel I was asking myself the wrong question. It shouldn’t have been “What is wrong with you?” but “What is wrong with this food?”

      Back in the 90s, there was no word to cover all the items I used to binge on. Some of the things I over-ate – crisps or chocolate or fast-food burgers – could be classified as junk food, but others, such as bread and cereal, were more like household staples. These various foods seemed to have nothing in common except for the fact that I found them very easy to eat a lot of, especially when sad. As I ate my Pringles and my white bread, I felt like a failure for not being able to stop. I had no idea that there would one day be a technical explanation for why I found them so hard to resist. The word is “ultra-processed” and it refers to foods that tend to be low in essential nutrients, high in sugar, oil and salt and liable to be overconsumed.

      Which foods qualify as ultra-processed? It’s almost easier to say which are not. I got a cup of coffee the other day at a train station cafe and the only snacks for sale that were not ultra-processed were a banana and a packet of nuts. The other options were: a panini made from ultra-processed bread, flavoured crisps, chocolate bars, long-life muffins and sweet wafer biscuits – all ultra-processed.

      What characterises ultra-processed foods is that they are so altered that it can be hard to recognise the underlying ingredients. These are concoctions of concoctions, engineered from ingredients that are already highly refined, such as cheap vegetable oils, flours, whey proteins and sugars, which are then whipped up into something more appetising with the help of industrial additives such as emulsifiers.

      Ultra-processed foods (or UPF) now account for more than half of all the calories eaten in the UK and US, and other countries are fast catching up. UPFs are now simply part of the flavour of modern life. These foods are convenient, affordable, highly profitable, strongly flavoured, aggressively marketed – and on sale in supermarkets everywhere. The foods themselves may be familiar, yet the term “ultra-processed” is less so. None of the friends I spoke with while writing this piece could recall ever having heard it in daily conversation. But everyone had a pretty good hunch what it meant. One recognised the concept as described by the US food writer Michael Pollan – “edible foodlike substances”.

      Some UPFs, such as sliced bread or mass-produced cakes, have been around for many decades, but the percentage of UPFs in the average person’s diet has never been anything like as high as it is today. It would be unusual for most of us to get through the day without consuming at least a few ultra-processed items.

      You might say that ultra-processed is just a pompous way to describe many of your normal, everyday pleasures. It could be your morning bowl of Cheerios or your evening pot of flavoured yoghurt. It’s savoury snacks and sweet baked goods. It’s chicken nuggets or vegan hotdogs, as the case may be. It’s the doughnut you buy when you are being indulgent, and the premium protein bar you eat at the gym for a quick energy boost. It’s the long-life almond milk in your coffee and the Diet Coke you drink in the afternoon. Consumed in isolation and moderation, each of these products may be perfectly wholesome. With their long shelf life, ultra-processed foods are designed to be microbiologically safe. The question is what happens to our bodies when UPFs become as prevalent as they are at the moment.

      Evidence now suggests that diets heavy in UPFs can cause overeating and obesity. Consumers may blame themselves for overindulging in these foods, but what if it is in the nature of these products to be overeaten?

      In 2014, the Brazilian government took the radical step of advising its citizens to avoid UPFs outright. The country was acting out of a sense of urgency, because the number of young Brazilian adults with obesity had risen so far and so fast, more than doubling between 2002 and 2013 (from 7.5% of the population to 17.5%). These radical new guidelines urged Brazilians to avoid snacking, and to make time for wholesome food in their lives, to eat regular meals in company when possible, to learn how to cook and to teach children to be “wary of all forms of food advertising”.

      The biggest departure in the Brazilian guidelines was to treat food processing as the single most important issue in public health. This new set of rules framed unhealthy food less in terms of the nutrients it contains (fats, carbohydrates etc) and more by the degree to which it is processed (preserved, emulsified, sweetened etc). No government diet guidelines had ever categorised foods this way before. One of the first rules in the Brazilian guidelines was to “avoid consumption of ultra-processed products”. They condemned at a stroke not just fast foods or sugary snacks, but also many foods which have been reformulated to seem health-giving, from “lite” margarines to vitamin-fortified breakfast cereals.

      From a British perspective – where the official NHS Eatwell guide still classifies low-fat margarines and packaged cereals as “healthier” options – it looks extreme to warn consumers off all ultra-processed foods (what, even Heinz tomato soup?). But there is evidence to back up the Brazilian position. Over the past decade, large-scale studies from France, Brazil, the US and Spain have suggested that high consumption of UPFs is associated with higher rates of obesity. When eaten in large amounts (and it’s hard to eat them any other way) they have also been linked to a whole host of conditions, from depression to asthma to heart disease to gastrointestinal disorders. In 2018, a study from France – following more than 100,000 adults – found that a 10% increase in the proportion of UPFs in someone’s diet led to a higher overall cancer risk. “Ultra-processed” has emerged as the most persuasive new metric for measuring what has gone wrong with modern food.

      W hy should food processing matter for our health? “Processed food” is a blurry term and for years, the food industry has exploited these blurred lines as a way to defend its additive-laden products. Unless you grow, forage or catch all your own food, almost everything you consume has been processed to some extent. A pint of milk is pasteurised, a pea may be frozen. Cooking is a process. Fermentation is a process. Artisanal, organic kimchi is a processed food, and so is the finest French goat’s cheese. No big deal.

      But UPFs are different. They are processed in ways that go far beyond cooking or fermentation, and they may also come plastered with health claims. Even a sugary multi-coloured breakfast cereal may state that it is “a good source of fibre” and “made with whole grains”. Bettina Elias Siegel, the author of Kid Food: The Challenge of Feeding Children in a Highly Processed World, says that in the US, people tend to categorise food in a binary way. There is “junk food” and then there is everything else. For Siegel, “ultra-processed” is a helpful tool for showing new parents that “there’s a huge difference between a cooked carrot and a bag of industrially produced, carrot-flavoured veggie puffs” aimed at toddlers, even if those veggie puffs are cynically marketed as “natural”.

      The concept of UPFs was born in the early years of this millennium when a Brazilian scientist called Carlos Monteiro noticed a paradox. People appeared to be buying less sugar, yet obesity and type 2 diabetes were going up. A team of Brazilian nutrition researchers led by Monteiro, based at the university of Sao Paulo, had been tracking the nation’s diet since the 80s, asking households to record the foods they bought. One of the biggest trends to jump out of the data was that, while the amount of sugar and oil people were buying was going down, their sugar consumption was vastly increasing, because of all of the ready-to-eat sugary products that were now available, from packaged cakes to chocolate breakfast cereal, that were easy to eat in large quantities without thinking about it.

      Photograph: Katrina Wittkamp/Getty

      To Monteiro, the bag of sugar on the kitchen counter is a healthy sign, not because sugar itself has any goodness in it, but because it belongs to a person who cooks. Monteiro’s data suggested to him that the households who were still buying sugar were also the ones who were still making the old Brazilian dishes such as rice and beans.

      Monteiro is a doctor by training, and when you talk to him, he still has the idealistic zeal of someone who wants to prevent human suffering. He had started off in the 70s treating poor people in rural villages, and was startled to see how quickly the problems of under-nutrition were replaced by those of tooth decay and obesity, particularly among children. When Monteiro looked at the foods that had increased the most in the Brazilian diet – from cookies and sodas to crackers and savoury snacks – what they had in common was that they were all highly processed. Yet he noticed that many of these commonly eaten foods did not even feature in the standard food pyramids of US nutrition guidelines, which show rows of different whole foods according to how much people consume, with rice and wheat at the bottom, then fruits and vegetables, then fish and dairy and so on. These pyramids are based on the assumption that people are still cooking from scratch, as they did in the 50s. “It is time to demolish the pyramid”, wrote Monteiro in 2011.

      Once something has been classified, it can be studied. In the 10 years since Monteiro first announced the concept, numerous peer-reviewed studies on UPFs have been published confirming the links he suspected between these foods and higher rates of disease. By giving a collective name to ultra-processed foods for the first time, Monteiro has gone some way to transforming the entire field of public health nutrition.

      As he sees it, there are four basic kinds of food, graded by the degree to which they are processed. Taken together, these four groups form what Monteiro calls the Nova system (meaning a new star). The first category – group 1 – are the least processed, and includes anything from a bunch of parsley to a carrot, from a steak to a raisin. A pedant will point out that none of these things are strictly unprocessed by the time they are sold: the carrot is washed, the steak is refrigerated, the raisin is dried. To answer these objections, Monteiro renamed this group “unprocessed and minimally processed foods”.

      The second group is called “processed culinary ingredients”. These include butter and salt, sugar and lard, oil and flour – all used in small quantities with group 1 foods to make them more delicious: a pat of butter melting on broccoli, a sprinkling of salt on a piece of fish, a spoonful of sugar in a bowl of strawberries.

      Next in the Nova system comes group 3, or “processed foods”. This category consists of foods that have been preserved, pickled, fermented or salted. Examples would be canned tomatoes and pulses, pickles, traditionally made bread (such as sourdough), smoked fish and cured meats. Monteiro notes that when used sparingly, these processed foods can result in “delicious dishes” and nutritionally balanced meals.

      The final category, group 4, is unlike any of the others. Group 4 foods tend to consist largely of the sugars, oils and starches from group 2, but instead of being used sparingly to make fresh food more delicious, these ingredients are now transformed through colours, emulsifiers, flavourings and other additives to become more palatable. They contain ingredients unfamiliar to domestic kitchens such as soy protein isolate (in cereal bars or shakes with added protein) and “mechanically separated meat” (turkey hotdogs, sausage rolls).

      Group 4 foods differ from other foods not just in substance, but in use. Because they are aggressively promoted and ready-to-eat, these highly profitable items have vast market advantages over the minimally processed foods in group 1. Monteiro and his colleagues have observed from evidence around the world that these group 4 items are liable to “replace freshly made regular meals and dishes, with snacking any time, anywhere”. For Monteiro, there is no doubt that these ultra-processed foods are implicated in obesity as well as a range of non-communicable diseases such as heart disease and type 2 diabetes.

      Not everyone in the world of nutrition is convinced by the Nova system of food classification. Some critics of Monteiro have complained that ultra-processed is just another way to describe foods that are sugary or fatty or salty or low in fibre, or all of these at once. If you look at the UPFs that are consumed in the largest quantities, the majority of them take the form of sweet treats or sugary drinks. The question is whether these foods would still be harmful if the levels of sugar and oil could be reduced.

      T he first time the nutrition researcher Kevin Hall heard anyone talk about ultra-processed food, he thought it was “a nonsense definition”. It was 2016 and Hall – who studies how people put on weight at the National Institute of Diabetes and Digestive and Kidney Diseases at Bethesda, Maryland – was at a conference chatting with a representative from PepsiCo who scornfully mentioned the new Brazilian set of food guidelines and specifically the directive to avoid ultra-processed foods. Hall agreed that this was a silly rule because, as far as he was concerned, obesity had nothing to do with food processing.

      Anyone can see that some foods are processed to a higher degree than others – an Oreo is not the same as an orange – but Hall knew of no scientific proof that said the degree of processed food in a person’s diet could cause them to gain weight. Hall is a physicist by training and he is a self-confessed “reductionist”. He likes to take things apart and see how they work. He is therefore attracted to the idea that food is nothing more than the sum of its nutrient parts: fats plus carbs plus protein and fibre, and so on. The whole notion of ultra-processed foods annoyed him because it seemed too fuzzy.

      When Hall started to read through the scientific literature on ultra-processed foods, he noticed that all of the damning evidence against them took the form of correlation rather than absolute proof. Like most studies on the harmful effects of particular foods, these studies fell under the umbrella of epidemiology: the study of patterns of health across populations. Hall – and he is not alone here – finds such studies less than convincing. Correlation is not causation, as the saying goes.

      Just because people who eat a lot of UPFs are more likely to be obese or suffer from cancer does not mean that obesity and cancer are caused by UPFs, per se. “Typically, it’s people in lower economic brackets who eat a lot of these foods,” Hall said. He thought UPFs were being wrongly blamed for the poor health outcomes of living in poverty.

      At the end of 2018, Hall and his colleagues became the first scientists to test – in randomised controlled conditions – whether diets high in ultra-processed foods could actually cause overeating and weight gain.

      For four weeks, 10 men and 10 women agreed to be confined to a clinic under Hall’s care and agreed to eat only what they were given, wearing loose clothes so that they would not notice so much if their weight changed. This might sound like a small study, but carefully controlled trials like this are considered the gold standard for science, and are especially rare in the field of nutrition because of the difficulty and expense of persuading humans to live and eat in laboratory conditions. Barry Popkin, a professor of nutrition at the University of North Carolina, has praised Hall’s study – published in Cell Metabolism – for being “as good a clinical trial as you can get”.

      For two weeks, Hall’s participants ate mostly ultra-processed meals such as turkey sandwiches with crisps, and for another two weeks they ate mostly unprocessed food such as spinach omelette with sweet potato hash. The researchers worked hard to design both sets of meals to be tasty and familiar to all participants. Day one on the ultra-processed diet included a breakfast of Cheerios with whole milk and a blueberry muffin, a lunch of canned beef ravioli followed by cookies and a pre-cooked TV dinner of steak and mashed potatoes with canned corn and low-fat chocolate milk. Day one on the unprocessed diet started with a breakfast of Greek yoghurt with walnuts, strawberries and bananas, a lunch of spinach, chicken and bulgur salad with grapes to follow, and dinner of roast beef, rice pilaf and vegetables, with peeled oranges to finish. The subjects were told to eat as much or as little as they liked.

      Hall set up the study to match the two diets as closely as possible for calories, sugar, protein, fibre and fat. This wasn’t easy, because most ultra-processed foods are low in fibre and protein and higher in sugar. To compensate for the lack of fibre, the participants were given diet lemonade laced with soluble fibre to go with their meals during the two weeks on the ultra-processed diet.

      It turned out that, during the weeks of the ultra-processed diet, the volunteers ate an extra 500 calories a day, equivalent to a whole quarter pounder with cheese. Blood tests showed that the hormones in the body responsible for hunger remained elevated on the ultra-processed diet compared to the unprocessed diet, which confirms the feeling I used to have that however much I ate, these foods didn’t sate my hunger.

      Photograph: Jochen Tack/Alamy

      Hall’s study provided evidence that an ultra-processed diet – with its soft textures and strong flavours – really does cause over-eating and weight gain, regardless of the sugar content. Over just two weeks, the subjects gained an average of 1kg. This is a far more dramatic result than you would expect to see over such a short space of time (especially since the volunteers rated both types of food as equally pleasant).

      After Hall’s study was published in July 2019, it was impossible to dismiss Monteiro’s proposition that the rise of UPFs increases the risk of obesity. Monteiro told me that as a result of Hall’s study, he and his colleagues in Brazil found they were suddenly being taken seriously.

      Now that we have evidence of a link between diets high in UPFs and obesity, it seems clear that a healthy diet should be based on fresh, home-cooked food. To help champion home cooking among Brazilians, Monteiro recruited the cookery writer Rita Lobo, whose website Panelinha (“network”) is the most popular food site in Brazil, with 3m hits a month. Lobo said that when she tells people about UPFs, the first reaction is panic and anger. “They say: ‘Oh my God! I’m not going to be able to eat my yoghurt or my cereal bar! What am I going to eat?’” After a while, however, she says that the concept of ultra-processed foods is “almost a relief” to people, because it liberates them from the polarities and restriction created by fad diets or “clean eating’”. People are thrilled, Lobo says, when they realise they can have desserts again, as long as they are freshly made.

      But modern patterns of work do not make it easy to find the time to cook every day. For households who have learned to rely on ultra-processed convenience foods, returning to home cooking can seem daunting – and expensive. Hall’s researchers in Maryland spent 40% more money purchasing the food for the unprocessed diet. (However, I noticed that the menu included large prime cuts of meat or fish every day it would be interesting to see how the cost would have compared with a larger number of vegetarian meals or cheaper cuts of meat.)

      In Brazil, cooking from scratch still tends to be cheaper than eating ultra-processed food, Lobo says. UPFs are a relative novelty in Brazil and memories of a firm tradition of home cooking have not died yet here. “In Brazil, it doesn’t matter if you are rich or poor, you grew up eating rice and beans. The problem for you [in the UK],” Lobo remarks, “is that you don’t know what your ‘rice and beans’ is.”

      I n Britain and the US, our relationship with ultra-processed food is so extensive and goes back so many decades that these products have become our soul food, a beloved repertoire of dishes. It’s what our mothers fed us. If you want to bond with someone who was a child in 1970s Britain, mention that you have childhood memories of being given Findus Crispy Pancakes and spaghetti hoops followed by Angel Delight for tea. I have noticed that Australian friends have similar conversations about the childhood joys of Tim Tams chocolate biscuits. In the curious coding of the British class system, a taste for industrial branded foods is a way to reassure others that you are OK. What kind of snob would disparage a Creme Egg or fail to recognise the joy of licking cheesy Wotsit dust from your fingers?

      I am as much of a sucker for this branded food nostalgia as anyone. There is a part of my brain – the part that is still an eight-year-old at a birthday party – that will always feel that Iced Gems (ultra-processed cookies topped with ultra-processed frosting) are pure magic. But I’ve started to feel a creeping unease that our ardent affection for these foods has been mostly manufactured by the food corporations who profit from selling them. For the thousands of people trapped in binge-eating disorder – as I once was – UPFs are false friends.

      The multinational food industry has a vested interest in rubbishing Monteiro’s ideas about how UPFs are detrimental to our health. And much of the most vociferous criticism of his Nova system has come from sources close to the industry. A 2018 paper co-authored by Melissa Mialon, a French food engineer and public health researcher, identified 32 materials online criticising Nova, most of which were not peer-reviewed. The paper showed that, out of 38 writers critical of Nova, 33 had links to the ultra-processed food industry.

      For many in the developing world, the prevalence of ultra-processed foods is making it hard for those on a limited budget to feed their children a wholesome diet. Victor Aguayo, chief of nutrition at Unicef, tells me over the phone that, as ultra-processed foods become cheaper and other foods, such as vegetables and fish, become more expensive, the UPFs are taking up a bigger volume of children’s diets. What’s more, the pleasurable textures and aggressive marketing of these foods makes them “appealing and aspirational” both to children and parents, says Aguayo.

      Soon after the arrival in Nepal of brightly coloured packages that, as Aguayo describes them, “look like food for children: the cookies, the savoury snacks, the cereals”, aid workers started to see an epidemic of “both overweight and micronutrient deficiency” including anaemia among Nepalese children under the age of five.

      Aguayo says there is an urgent need to change the food environment to make the healthy options the easy, affordable and available ones. Ecuador, Uruguay and Peru have followed Brazil’s example in urging their citizens to steer clear of ultra-processed foods. Uruguay’s dietary guidelines – issued in 2016 – tells Uruguayans to “base your diet on natural foods, and avoid the regular consumption of ultra-processed products”. How easy this will be to do is another matter.

      I n Australia, Canada or the UK, to be told to avoid ultra-processed food – as the Brazilian guidelines do – would mean rejecting half or more of what is for sale as food, including many basic staples that people depend on, such as bread. The vast majority of supermarket loaves count as ultra-processed, regardless of how much they boast of being multiseed, malted or glowing with ancient grains.

      Earlier this year, Monteiro and his colleagues published a paper titled “Ultra-processed foods: what they are and how to identify them”, offering some rules of thumb. The paper explains that “the practical way to identify if a product is ultra-processed is to check to see if its list of ingredients contains at least one food substance never or rarely used in kitchens, or classes of additives whose function is to make the final product palatable or more appealing (‘cosmetic additives’)”. Tell-tale ingredients include “invert sugar, maltodextrin, dextrose, lactose, soluble or insoluble fibre, hydrogenated or interesterified oil”. Or it may contain additives such as “flavour enhancers, colours, emulsifiers, emulsifying salts, sweeteners, thickeners and anti-foaming, bulking, carbonating, foaming, gelling and glazing agents”.

      But not everyone has time to search every label for the presence of glazing agents. A website called Open Food Facts, run by mostly French volunteers, has started the herculean labour of creating an open database of packaged foods around the world and listing where they fit into on the Nova system. Froot Loops: Nova 4. Unsalted butter: Nova 2. Sardines in olive oil: Nova 3. Vanilla Alpro yoghurt: Nova 4. Stéphane Gigandet, who runs the site, says that he started analysing food by Nova a year ago and “it is not an easy task”.

      For most modern eaters, avoiding all ultra-processed foods is unsettling and unrealistic, particularly if you are on a low income or vegan or frail or disabled, or someone who really loves the occasional cheese-and-ham toastie made from sliced white bread. In his early papers, Monteiro wrote of reducing ultra-processed items as a proportion of the total diet rather than cutting them out altogether. Likewise, the French Ministry of Health has announced that it wants to reduce consumption of Nova 4 products by 20% over the next three years.

      We still don’t really know what it is about ultra-processed food that generates weight gain. The rate of chewing may be a factor. In Hall’s study, during the weeks on the ultra-processed diet people ate their meals faster, maybe because the foods tended to be softer and easier to chew. On the unprocessed diet, a hormone called PYY, which reduces appetite, was elevated, suggesting that homemade food keeps us fuller for longer. The effect of additives such as artificial sweeteners on the gut microbiome is another theory. Later this year, new research from physicist Albert-László Barabási will reveal more about the way that ultra-processing actually alters food at a molecular level.

      In a two-part blog on ultra-processed foods in 2018 (Rise of the Ultra Foods) Anthony Warner, a former food industry development chef who tweets and campaigns as Angry Chef, argued that Nova was stoking fear and guilt about food and “adding to the stress of already difficult lives” by making people feel judged for their food choices. But having read Kevin Hall’s study, he wrote an article in May 2019 admitting: “I was wrong about ultra-processed food – it really is making you fat.” Warner said the study convinced him that “eating rate, texture and palatability” of UPFs lead to overeating, and ended with a call for more research.

      Hall tells me that he is in the process of constructing another study on ultra-processed food and obesity. This time, the people on the ultra-processed diet would also be eating larger amounts of unprocessed foods, such as crunchy vegetables with low energy density, while still getting more than 80% of their calories from ultra-processed food – equivalent to adding a side salad or a portion of broccoli to your dinner of frozen pizza. This is much closer to how most families actually eat.

      Even if scientists do succeed in pinning down the mechanism or mechanisms by which ultra-processed foods make us gain weight, it’s not clear what policy-makers should do about UPFs, except for giving people the support and resources they need to cook more fresh meals at home. To follow the Brazilian advice entails a total rethink of the food system.

      Healthy alternatives to highly processed food

      • Buy local: When you buy from farmers’ markets, the food is fresher and there are fewer people involved in food handling, making it less processed. Locally grown foods also are more nutrient-dense.
      • Shop the perimeter of the store: Many foods found in the center aisles have added preservatives that help them stay “fresh.” Fresh foods, like dairy, fruits, and vegetables are found around the perimeter of grocery stores.
      • Swap refined grains for whole grains:Whole grains are considered “whole” because they retain the bran, germ, and endosperm of the grain seed. These parts of the grain seed are high in antioxidants, B vitamins, and protein. Refined grains are stripped of these three parts of the seed, making them less nutritious.
      • Buymore fruits and vegetables: Swap ultra-processed foods for fresh fruits and vegetables. Fruits and vegetables are healthy snack options because they tend to be low in calories, high in nutrients, and contain no preservatives or added sugars.

      Finding a healthy balance

      With flavour, low-cost and convenience often appearing in the same brightly coloured package, it's no big surprise that ultra-processed foods form such a large part of our diet.

      They're also often marketed as health foods, in the form of meal replacements, diet drinks and breakfast cereals.

      Dr Scrinis acknowledged many Australians put ultra-processed food into their shopping trollies because they were "cheap and convenient", but hoped the growing body of research would send a message to governments and food manufacturers that change was needed.

      "It's not simply a choice that people make. There are structural issues there in terms of people's affordability and availability of these foods," he said.

      "So it's not about cutting them out completely, but it's just being aware how much these foods make up to the totality of our diets."