Ultra-processed foods are highly altered and typically contain a lot of added salt, sugar, fat, and industrial chemical additives. Scientists have shown that eating a lot of ultra-processed food is not good for your health.
Our diets can have a big impact on our overall health, including our gut microbiome. Although regularly eating ultra-processed foods like chips, microwave meals, candy, and chicken nuggets is not a healthy diet, processed food is not all bad.
In this article, we dive into the research and explore the difference between processed and ultra-processed food, why too much ultra-processed food is harmful to our health, and how we can consume less of it to achieve a better balance.
What is ultra-processed food?
The terms “processed” and “ultra-processed” are thrown around a lot and are usually associated with something negative, but what makes something processed or ultra-processed?
Unless you’re eating the broccoli you harvested directly from your garden, most of the food we eat daily has undergone some form of processing. But that’s not necessarily a bad thing, as we’ll discover.
Processing food means changing its natural state to prolong its shelf life, make it safe to store or eat, enhance its taste, or even increase its nutritional value.
Methods like pasteurizing, canning, fermenting, freezing, and drying foods are forms of processing.
When a food is ultra-processed, it means that the producer uses industrial-scale methods and ingredients that you may not recognize and would not use in home cooking to produce the final product.
The NOVA food classification system divides food products into four groups based on how much processing they have gone through.
The four NOVA groups are as follows:
1. Unprocessed or minimally processed foods
Minimally processed or unprocessed food has not been altered or has no added ingredients. Washed and bagged spinach, pre-cut fresh fruit, or frozen vegetables are all minimally processed. They’re made to be more convenient to consume, but their nutritional value hasn’t been altered.
2. Processed culinary ingredients
Processed culinary ingredients are made from unprocessed foods through simple processing. This group includes oil, butter, sugar, salt, dried herbs, and spices. They are added to other foods, rather than eaten by themselves.
3. Processed foods
Processed foods are partially altered by adding sugar, oil, fat, salt, and other culinary ingredients to minimally processed foods. Processed foods like cheese, homemade or artisanal bread, and tofu have been altered, but not in a way that’s bad for our health.
4. Ultra-processed foods
Ultra-processed foods are entirely altered and have high levels of unhealthy fats, refined sugars, and salt.
They also undergo industrial processes, like hydrogenation and moulding, and contain additives like dyes, stabilizers, flavor enhancers, emulsifiers, and defoaming agents.
These foods are very calorie-dense and don’t contain many, if any, valuable nutrients. Cookies, chips, and fast food are all ultra-processed.
Ultra-processed foods are engineered to be convenient, extra tasty, and highly profitable for the companies that make them.
Is ultra-processed food unhealthy?
The consensus is that ultra-processed food is unhealthy. Diets high in ultra-processed foods have been linked with increased risk of heart disease, weight gain, cancer, and even mortality — but why?
Processing changes the complex structure of nutrients in a food, which scientists call the food matrix.
Furthermore, research has shown that changes in the food matrix alter the way our bodies respond to food, potentially putting us at risk of these health conditions.
Let’s look at what the research says about ultra-processed food and its effect on our health.
One study analyzed the diets of more than 44,000 French adults for 7 years and found that high consumption of ultra-processed foods was linked with an increased risk of death. A study of almost 20,000 adults in Spain had similar findings.
Another large study of over 100,000 French adults followed over 5 years showed that eating more ultra-processed foods was linked with a greater risk of heart disease.
A similar analysis of the same participants found that a 10% increase in ultra-processed food consumption was linked with a 12% higher risk of cancer.
Although these studies were significant, their observational nature cannot prove cause and effect.
Effects of eating ultra-processed food
One recent clinical trial, however, studied what happened when participants ate ultra-processed food in detail.
The scientists asked 20 people to live in a dedicated clinical trial unit for 4 weeks. They presented the participants with either ultra-processed or unprocessed diets for 2 weeks, immediately followed by the alternate diet for 2 weeks.
The volunteers could eat as much or as little as they liked. The researchers found that the participants who ate the ultra-processed diet consumed roughly an extra 500 calories a day, compared with those eating the unprocessed diet.
This led to an average weight gain of 2 pounds in the 2 weeks that the volunteers ate the ultra-processed food.
Aside from weight gain, scientists believe that ultra-processed foods also affect gut health. This could be because ultra-processed food often lacks fiber, which plays an essential role in keeping your microbiome healthy.
ZOE’s PREDICT study, the largest nutritional study of its kind, showed that eating a diet rich in highly processed foods was associated with an increase of “bad” or potentially harmful gut microbes.
The microbes in your gut play a key role in your health. They help support a healthy immune system, digest your food, and regulate how your body responds to what you eat.
A gut microbiome that heavily features potentially harmful “bad” bugs has been linked with a greater risk of developing cancer, heart disease, type 2 diabetes, and obesity.
The ZOE program can identify what bugs are in your gut and how your body responds to the food you eat, helping you make informed choices about your health and how to best nourish your body.
Common ultra-processed foods
Ultra-processed food is incredibly common, and chances are that most of us eat some ultra-processed food daily.
People in the U.S. and the U.K. consume more than half of their calories each day from ultra-processed food. Remember, this type of food is not only inexpensive, but also heavily marketed.
Many people rely on ultra-processed food to feed themselves and their families because it’s affordable and accessible. Having the time, resources, and facilities to consume and cook fresh food is a privilege that not everyone has.
Examples of common ultra-processed foods are:
soda and carbonated drinks
sweet and savory packaged snacks (e.g., chips and cookies)
energy bars or granola bars
sausages, hot dogs, and cold cuts
One way to reduce how much ultra-processed food you eat is by prioritizing unprocessed or minimally processed food.
Unprocessed or minimally processed foods you can increase in your diet include:
fruit and vegetables (both fresh and frozen)
dried fruits and nuts with no added sugar, salt, or oil
pulses and legumes (such as chickpeas and lentils)
whole grain starchy carbohydrates (whole wheat bread, oats, whole wheat pasta)
fresh meat, poultry, fish, and eggs
plain or natural yogurt with no added sugar
spices and herbs
tea, coffee, water
Other actions you can take to cut back on ultra-processed foods are:
cooking at home as often as you can
bringing a packed lunch to school or work
checking food labels for saturated fat, sodium, and sugar quantity
snacking on whole foods, rather than pre-packaged snacks
trying to reduce how much fast food you eat
Although research shows that regularly eating ultra-processed foods is bad for your health, cutting these out of your diet entirely may be a challenge.
It’s undeniable that what you eat affects your overall health long-term, and overconsuming ultra-processed food puts you at a higher risk of disease.
But there’s no need to get down on yourself for eating a frozen pizza or fast-food meal now and again.
At ZOE, we believe that no food should be off limits and that you can have a balanced, healthy diet that occasionally includes ultra-processed food.
To learn how the food that you eat uniquely affects your body, check out the ZOE program.
Using cutting-edge science from the world’s largest nutritional study, our program is tailored to your individual biology and will teach you how to make smart food swaps and combine foods to make them work for your body.
Association between consumption of ultra-processed foods and all cause mortality: SUN prospective cohort study. (2019).
Association between ultraprocessed food consumption and risk of mortality among middle-aged adults in France. (2019).
Consumption of ultra-processed foods and cancer risk: results from NutriNet-Santé prospective cohort. (2018).
Modulation of postprandial lipaemia by a single meal containing a commonly consumed interesterified palmitic acid-rich fat blend compared to a non-interesterified equivalent. (2016).
The UN Decade of Nutrition, the NOVA food classification and the trouble with ultra-processing. (2017)
Ultra-processed diets cause excess calorie intake and weight gain: An inpatient randomized controlled trial of ad libitum food intake. (2019).
Ultra-processed foods and added sugars in the US diet: evidence from a nationally representative cross-sectional study. (2016).
Ultra-processed foods and excessive free sugar intake in the UK: a nationally representative cross-sectional study. (2019)
Ultra-processed food intake and risk of cardiovascular disease: prospective cohort study (NutriNet-Santé). (2019).