Evidence-Based Nutrition For Chronic Disease Prevention

Ultra-Processed Foods: The #1 Cause of Overeating and Weight Gain?

By Mario Kratz, PhD

Published May 25, 2022

The Global Nutrition Transition Towards Ultra-Processed Foods is Associated with the Global Obesity Epidemic

In a recent blog post, we discussed the global nutrition transition towards a food system characterized by increasingly industrialized agriculture and food manufacturing. In countries all around the world, a greater proportion of food is now produced in factories. It often consists of food components that have been extracted from whole foods, such as sugar, high-fructose corn syrup, vegetable oils, or protein isolates. These components are then assembled into what we now call ultra-processed foods, and “improved” by adding food additives such as artificial sweeteners, artificial colorants, emulsifiers, thickeners, or taste enhancers.

In most countries worldwide, the increased availability and consumption of ultra-processed foods is associated with rapidly rising rates of obesity. And even within nations, those populations or individuals who consume the most ultra-processed foods tend to weigh the most and are most likely to be obese.

Now, these are all associations, and – as compelling and consistent as they are – association does not equate to causation. 

So, is there any evidence that eating more ultra-processed foods causes people to eat more calories and gain weight?

Yes, there is, and in this blog post, we will discuss a high-quality randomized controlled clinical trial that has looked precisely at this question. We will also look more closely at what these ultra-processed foods are, and what it is about them that may make people overeat. And lastly, I’ll share how we can concretely use this information to prevent overeating and weight gain.

Ultra-Processed Foods Cause Overeating and Weight Gain

In 2019, Dr. Kevin Hall and colleagues at the U.S. National Institutes of Health put the idea that ultra-processed foods may cause overeating and weight gain to the test.

They enrolled 20 middle-aged men and women who were overweight and invited them to spend 28 consecutive days at a clinical research center. That means they could not leave and were only allowed to eat whatever food was served. This kind of feeding study is often called a metabolic ward study, and it’s one of the strongest types of nutrition studies because investigators know exactly what every participant eats, and how much of it. Researchers can also control some other critical factors, such as the participant’s level of physical activity.

Study Design. Figure created by the author, based on Hall et al.; Cell Metab. 2019; 30: 67-77

Researchers randomized participants into one of two groups. Group one first ate a diet of mostly unprocessed foods for two weeks, and then they switched to a diet of mostly ultra-processed foods. The second group received these same diets, but in reverse order.

On the ultra-processed food diet, ultra-processed food made up more than 80% of all calories served, and unprocessed foods made up 0%.

On the unprocessed food diet, unprocessed foods accounted for more than 80% of total calories served, and ultra-processed food only made up about 6%.

Study Diets. Figure created by the author, based on Hall et al.; Cell Metab. 2019; 30: 67-77

This type of study design is particularly strong because every participant completes both diet phases and can therefore serve as their own control.

Participants received three meals per day and had access to snacks all day as well.

The total amount of food provided was twice as much as the investigators estimated the participants would need. But participants were not required to eat all of it. Instead, they were asked to eat as much or as little of the food as they desired. Any food that was not consumed was returned to the research kitchen and weighed again. By comparing the food served to the food returned, the researchers could figure out exactly what had been eaten, and how much.

We’ll go over what kinds of foods were served on both diets, but for now, suffice it to say that the diets were designed to differ in the degree of processing. One diet consisted mostly of unprocessed or minimally processed foods, the other diet primarily of ultra-processed foods.

What did they find? 

They found that participants ate more calories on the ultra-processed foods diet. A lot more calories.

When these 20 men and women were eating the unprocessed food diet, they ate on average 2,470 kcal per day over the 14-day intervention period. But when these same 20 men and women ate the ultra-processed food diet, they ate an average of 2,979 kcal per day over 14 days. That is an insane 508 kcal per day more.

Study Results. Figure created by the author, based on Hall et al.; Cell Metab. 2019; 30: 67-77

Some uncertainty is associated with these measured calorie intake numbers. As explained in the last blog post, even in a randomized controlled trial we cannot be 100% certain that the difference in calorie intake between these two diets would always be exactly 508 kcal/day if we had a chance to run the study again. The 95% confidence interval (CI) tells us that we can be 95% confident that we would find calorie intake to be higher by between 300 and 716 kcal/day in the ultra-processed foods diet. In other words, we are almost certain that calorie intake would always be higher on that diet, no matter how often we ran the study, and by a lot. And that’s why the p-value is so low. This type of result provides a very high level of confidence that the observation of substantially higher calorie intake on the ultra-processed foods diet is reflective of a real effect and not just the result of random variation.

Remember that participants were given more food than they could eat, and asked to eat as much or as little of the food as they desired. This means that just by being given ultra-processed food, they desired a lot more calories than when they were eating unprocessed foods.

Well, if they ate this much more food, that must be because they were a lot hungrier for some reason during the ultra-processed food diet period, right? No, reported feelings of hunger were almost identical during the two diet periods.

But then they must have reported being a lot more full when they ate these extra 500+ calories per day on the ultra-processed food diet! Again no, because again they reported the exact same degree of fullness and satisfaction during both diet periods.

So, participants experienced the same level of hunger and ate to the same level of fullness on both diets, but for some reason, 500+ calories per day more were required of the ultra-processed foods than of the unprocessed foods to achieve this level of desired fullness.

Most of us probably think that when we feel full and stop eating depends on when we have eaten enough calories. This research clearly shows that very different numbers of calories can make us feel similarly full, dependent on which specific foods we are eating.

What is so remarkable about this is that this was the case over an entire 2-week period. Eating mostly ultra-processed foods resulted in each participant having Thanksgiving-type overeating for 14 days in a row. I would have thought that, yes, people would overeat for a day or two, but then slowly, the body would react to this overeating and reduce hunger and appetite. That did happen, but only to a much smaller degree than I would have anticipated.

Let’s let this sink in for a minute. Our body balances calorie intake and energy expenditure without us consciously counting calories or keeping track of our steps. Even if we consider that most adults in, say, the United States gain an average of 1-2 pounds per year, that is still the case. Because a weight gain of 1-2 pounds per year means a daily calorie excess of ~20-50 kcal. It is difficult to calculate the exact calorie surplus required for a 1-2 pound per year weight gain, because energy expenditure changes as we gain weight. The point is that the “error” made by the body in matching calorie intake to energy expenditure makes up at most 1-2% of total intake for most people even as they are gaining weight.

That just eating mostly ultra-processed foods causes an increase in calorie intake by more than 500 kcal per day suggests that these foods somehow slip by those systems in our brains that register calorie intake and regulate our appetite. 

And it also suggests that even if a person eats ultra-processed foods only occasionally, that could trigger an energy intake surplus that could easily explain the annual weight gain of most adults.

With this vast difference in calorie intake, no one will be shocked to hear that participants gained about two pounds when they ate the ultra-processed food diet, and lost about two pounds when they ate the diet rich in unprocessed foods. That is because they switched from an average American diet where about 50% of calories come from ultra-processed food, so ultra-processed food intake went up in one diet phase and down in the other. And calorie intake and weight followed right along with these changes in ultra-processed food intakes.

What are Ultra-Processed Foods?

Now, before we look at what specifically the study diets consisted of, let’s quickly review the definition of ultra-processed foods, so that we are all clear what we are talking about.

The NOVA classification of foods based on their degree of processing. Based on Monteiro et al.; FAO, Rome, 2019.

The NOVA classification system is a commonly used way to categorize foods by their degree of processing. In this system, we don’t categorize foods according to their nutrient content, but consider whether and how much a food has been processed. Ultra-processed foods (category 4) are “Industrial formulations of foods with typically 5 or more and usually many ingredients”. Typical components of ultra-processed foods are salt, sugar or high-fructose corn syrup, added oils and fats, and a long list of “substances not commonly used in culinary preparations”. These include hydrolyzed proteins, modified starches, hydrogenated oils, artificial sweeteners, artificial colors, artificial flavors, emulsifiers, and firming, de-foaming, anticaking, and glazing agents. And that’s not even a comprehensive list.

On the other end of the spectrum, unprocessed or minimally processed foods (category 1) include all of your vegetables, fruit, nuts and seeds, meat, fish, milk, eggs, and legumes. These are still grouped in category 1 even if they are minimally processed, such as cut or dried, boiled, roasted, refrigerated, or frozen.

Category 2 refers to processed culinary ingredients, such as oils, sugar, butter, or salt. 

Category 3 are processed foods, including canned fish, canned vegetables, and canned fruit in syrup. These have been processed by various cooking and packaging methods. Foods that have been produced by non-alcoholic fermentation, such as traditional cheese or an artisan sourdough bread, for example, also fall into this category. Usually, these foods have just 2-3 ingredients.

I personally actually don’t like how this NOVA category 3 was defined. As mentioned, this category includes foods that most nutrition professionals would consider healthy, nutrient-dense foods, such as canned vegetables, canned fish, or cheese. And it also includes processed empty-calorie foods that don’t meet the criteria for category 4. A homemade cookie prepared from flour, sugar, and butter would be an example of this. I am hoping that the field will develop subcategories to differentiate these types of processed foods.

What Did The Study Diets Look Like?

With that out of the way, let’s look at the foods given to participants in this study.

Breakfasts on the ultra-processed food diet varied quite a bit from day to day. One example breakfast was a sugary cereal with whole milk, and a commercial blueberry muffin with margarine. Looking at the ingredient lists, it is obvious that these are all ultra-processed foods, except for the whole milk. Each food has ingredients that were isolated from whole foods, such as soy lecithin, wheat gluten, or modified corn starch, and also ingredients that are not commonly used in culinary preparations, such as tripotassium phosphate or sodium aluminum phosphate.

Figure created by the author, based on Hall et al.; Cell Metab. 2019; 30: 67-77

For the control diet that received unprocessed foods, they didn’t just try to find equivalent foods that were less processed. For example, they could have given control participants regular corn flakes, which consist of cornmeal, sugar, and salt, as well as a homemade blueberry muffin with butter. That meal would not have included any ultra-processed food, but it would still have been mostly processed foods.

Instead, they chose foods that are truly unprocessed or only minimally processed, i.e. in category 1 according to NOVA classifications. Given that this was the first study of this kind that assessed the impact of processing on calorie intake, it does make sense that the investigators compared foods from opposing ends of the processing spectrum.

An example for the kind of breakfast that was served during the unprocessed diet period would be plain nonfat Greek yogurt with banana, strawberries, and walnuts, as well as apple slices with freshly-squeezed lemon juice.

Figure created by the author, based on Hall et al.; Cell Metab. 2019; 30: 67-77

An example of the type of lunch that was served during the ultra-processed foods diet period would be beef chili with beans, cheese, sour cream, tortilla chips, salsa, and canned peaches in syrup for dessert.

Pay attention to how these foods were actually produced, and which ingredients they contained. Beef and bean chili or cheese, for example, are not always ultra-processed. One could certainly make a beef chili at home, from scratch, that would not be categorized as ultra-processed because we probably wouldn’t add modified corn starch, textured vegetable protein, or ‘flavoring’ to it. 

Figure created by the author, based on Hall et al.; Cell Metab. 2019; 30: 67-77

An example lunch for the unprocessed food diet would be a large salad with spinach, grilled chicken breast, apple slices, cooked bulgur, sunflower seeds, and grapes with a vinaigrette dressing made from scratch.

Figure created by the author, based on Hall et al.; Cell Metab. 2019; 30: 67-77

So these diets were quite a bit different in many ways, but the investigators made sure participants were given real, typical meals on both diets. I am sure many of you have eaten a muffin or a beef chili such as those that were served in the ultra-processed foods arm of this study. I also know that many kids eat the very popular type of breakfast cereal that was used in the ultra-processed food diet. So these were commonly eaten foods, on both diets.

One thing that was neat about the study is that even though the meals differed in a lot of ways, the investigators decided to standardize the diets in terms of their macronutrient composition (i.e., the relative amounts of fat, carbohydrates, and protein), and their fiber content. They also tried to match the diets for sugar and sodium (salt) content, but the argument could be made that this was not entirely successful.

These were pretty mixed diets, with about 48% of total calories coming from carbohydrates, about 37% from fat, and 14-15% from protein.

Matching macronutrient composition worked pretty well, with the exception of protein, which was somewhat lower in the ultra-processed food diet (14.0 vs. 15.6% of total energy intake). That may not sound like much of a difference, but it could be meaningful.

Figure created by the author, based on Hall et al.; Cell Metab. 2019; 30: 67-77

The problem is that ultra-processed foods tend to have less protein than unprocessed foods. In their production, the manufacturers add cheap and highly palatable fats and oils, and carbohydrates, mainly in the form of refined grains and sugars. And adding fats and carbs to foods inevitably lowers the protein content in percent of total calories.

And it isn’t just the protein content that inherently differs between unprocessed and ultra-processed foods, but also the content of sugars, fiber, and sodium (from salt).

The researchers aimed to match fiber content by adding fiber to the ultra-processed diet, mostly to non-calorie beverages. But you see in the figure below that even though they tried, they were still unable to fully match the diets that were offered for fiber content. Because people ate more calories on the ultra-processed foods diet, total fiber intake was pretty similar in the two diets, as consumed, though.

Figure created by the author, based on Hall et al.; Cell Metab. 2019; 30: 67-77

Similarly, total sugar intake was not significantly different between the two diets, as consumed, even though sugar content was quite a bit higher in the foods offered during the unprocessed foods diet period. The source of sugar was different, though: the ultra-processed foods diet contained mostly added sugar, whereas in the unprocessed foods diet, it was mostly sugar present in whole fruit.

Figure created by the author, based on Hall et al.; Cell Metab. 2019; 30: 67-77

The two factors that were different between the two diets no matter how we look at it are the energy density (kcal per g of food) in the solid food, and sodium content.

Figure created by the author, based on Hall et al.; Cell Metab. 2019; 30: 67-77

I liked the fact that the investigators matched the diets in terms of their macronutrient composition. I would personally not have made the decision to attempt to match the diets for energy density, fiber, sugar, and sodium though. In my mind, it is an inherent characteristic of ultra-processed foods that they are more energy-dense, with more added sugar and salt and less fiber, and so these could be seen as mediating factors in the relationship between ultra-processed foods and the main endpoint of the study, calorie intake. ‘Mediating factor’ means that higher calorie intake on diets rich in ultra-processed foods could be due to these characteristics. And if you standardize the intervention diets for all of the potential mediating factors, it is likely that you create an artificial null result of no difference.

In conclusion, the two diets led to drastically different calorie intakes even though the investigators matched the two diets in terms of macronutrient composition and fiber content. If this had not been the case, it stands to reason that the differences in calorie intake and weight change may have been even more substantial. 

This trial, even though it’s just a single one for now, substantially strengthened the hypothesis that the increased consumption of ultra-processed foods could be a significant driver of the global obesity epidemic, because it shows that increased ultra-processed food consumption is not just associated with higher body weight, but actually causes overeating and weight gain compared to a diet consisting primarily of unprocessed foods.

Components of ultra-processed food that may promote overeating and weight gain

This compelling finding raises the question of what it is about ultra-processed foods that makes people overeat.

One fascinating observation the authors made was that the speed of eating in both kcal/min and g/min was a lot higher when participants ate the diet rich in ultra-processed foods. That is very interesting, because higher eating speeds can result in increased overall calorie intake.

That eating speed was higher when measured in kcal/min makes a lot of sense given that the solid food energy density (kcal/g) was a lot higher on the ultra-processed diet. That simply means that more calories were eaten with every bite. Higher energy density has previously been consistently linked to higher ad libitum energy intake, making it seem likely that the higher energy density is one of the factors that makes people overeat on ultra-processed foods.

However, eating speed was also higher when measured in g of food/min. This suggests that there may be more to the story than just the higher energy density.

One prominent hypothesis is that ultra-processed foods are designed to be hyperpalatable, which may make people more eager to eat them, plausibly increasing both eating speed and overall calorie intake. The authors did not detect any differences between the two diets when participants rated them by pleasantness and familiarity.

It is reassuring that the two diets were rated similarly in terms of their pleasantness, because it suggests that the differences in calorie intake between these two diets were not explained by a dislike of the unprocessed foods diet.

However, it is unclear whether these assessments are adequate to measure the specific response to hyperpalatable foods. It is well possible that we are not overconsuming ultra-processed foods because we find them more pleasant. My guess is that there are other dimensions of food liking and craving as well as the anticipated or perceived food reward that ultra-processed foods may act upon that were not measured in this study. Therefore, I would suggest that this study did not comprehensively answer whether hyperpalatability may be one of the qualities that makes people overeat ultra-processed foods. 

Higher eating speed and calorie intake may also be partly explained by the softer texture of many ultra-processed foods, as another study suggests. I guess we can all relate to this: just think about how much easier and faster it is to eat, say, cooked carrots than raw carrots.

One difference that may also matter is the lower protein content. A different study had found some evidence suggesting that the generally lower protein content of ultra-processed foods may partly explain the higher energy consumption on diets rich in these foods. According to the protein leverage hypothesis of obesity, the idea is that the body will make people eat more food and more calories whenever the protein content of the food is low, to make sure that protein intake is optimal. This would explain why high-protein diets are more potent at inducing satiety, reducing spontaneous calorie intake even in people who are not actively trying to reduce their calorie intake. And vice versa, it may partly explain why people eat more on diets with a lower protein content as a percentage of total calories, such as those rich in ultra-processed foods.

Dr. Hall and colleagues addressed this possibility statistically and found that the lower protein content of ultra-processed foods can, at most, explain about 50% of the calorie overconsumption seen on that diet.

Overall, the investigators did not design the study to identify which specific characteristics of ultra-processed foods are making people overeat. It, therefore, remains unclear to which degree hyperpalatability, higher energy density, softer texture, lower protein content, and potentially other factors play a role individually or in combination.

Future studies will surely be conducted to address this question. One possibility is that ultra-processed foods could theoretically be designed such that they do not trigger overeating and weight gain by, for example, giving them a lower energy density, a harder texture, or a higher protein content.

Personally, I think we would all be better off relying on unprocessed foods as the staples of our diet rather than hoping that the food industry will change the ultra-processing formula. However, many people rely heavily on these affordable, shelf-stable, and convenient foods. Making ultra-processed foods less detrimental to our health and eating more unprocessed foods is not mutually exclusive.

It is also unclear to which degree the much higher eating speed is necessary to trigger overeating on diets rich in ultra-processed foods. It does stand to reason that conscious efforts to eat more slowly and with breaks may counter excess calorie intake that results from eating these ultra-processed foods.

How Can We Use This Information If We Want to Prevent Overeating?

If we are looking at the totality of the evidence from observational studies and now this randomized controlled trial, it does seem very likely that ultra-processed foods are a major contributor to overeating and weight gain, and one of the primary culprits for the obesity epidemic.

Some questions remain, though. For example, it is unclear what it is about ultra-processed foods that makes people overeat them. Related to this, it is also quite likely that some ultra-processed foods are worse than others. And we may be able to create ultra-processed foods that are health-promoting rather than obesogenic once we understand which factors make us overeat ultra-processed foods.

For now, though, it does seem wise to limit ultra-processed food consumption as much as possible if we care about our health.

My biggest takeaway from all of these data is that the bulk of our diet should consist of unprocessed or minimally processed whole foods. Yes, we can replace some ultra-processed foods with less processed alternatives, and we will discuss a few examples of this below, but in general, these are not all that much healthier than the ultra-processed versions.

Let me give you an example.

Let’s look again at the example breakfast from the trial we discussed. A bowl of sugary breakfast cereal with milk, and a blueberry muffin with margarine.

We could replace the sugary ultra-processed breakfast cereal with simple corn flakes, which would be considered only a processed food (NOVA category 3). And we could replace the factory-made blueberry muffin with a homemade one. And then replace the margarine with butter. Even though it doesn’t look much different, this meal would now have 0% ultra-processed foods.

Would this be a better option? Yes, in my opinion, it would be, but not by much, because it is still a pretty processed meal, just less processed. 

We would be better off replacing this with an unprocessed, whole foods meal that is nutrient-dense, such as the breakfast example from the unprocessed food diet we discussed earlier: plain greek yogurt with fruit and nuts. 

It is similar for many other ultra-processed foods. For example, we could make pancakes at home, using a simple recipe like the one shown below on the left, rather than buying factory-made ultra-processed ones. These homemade pancakes would no longer qualify as ultra-processed food.

Or instead of, say, ranch-flavored tortilla chips, we could purchase the less processed simple ones with just a few ingredients.

I’d say that if we absolutely need to have some pancakes or corn chips, the less processed versions are the way to go. However, even if these less processed pancakes and tortilla chips are maybe a little less bad than their ultra-processed cousins, if we care for your health, we will want to make a more substantive shift in our food choices. In my family, we have pancakes and corn chips once in a while, but only as an occasional indulgence. On a regular basis, we would serve an omelette with vegetables for breakfast rather than pancakes, and I’ll offer my kids an apple and some nuts as a snack rather than corn chips.

So, I think you get the message: we do our health the greatest favor if we don’t replace ultra-processed foods with other processed foods that are maybe a little less bad, but instead replace them with unprocessed or minimally processed whole foods.

That said, there are certainly a lot of ultra-processed foods that would be a lot better if we made them from scratch at home. Chili would be a good example, using a simple recipe such as the one shown below on the left compared to a commercial ultra-processed chili.

Hash browns would be another good example. Just take a potato, cut it up, and fry it in some olive oil. Some salt and seasoning, done. 

Now, I like cooking, but I understand that not everyone likes it, or has the time for it. Sometimes, we just need something prepared that is quick and affordable and doesn’t require an hour in the kitchen, so let’s look at a few examples of what we should be looking for when we go shopping.

Bread is a great example. I would never, under any circumstances, buy this commercial white bread listed below on the right side. If we buy bread, we look for something like this very simple one on the left side. As a German, I have strong feelings about this: bread doesn’t need a whole bunch of ingredients: water, flour, and salt are just fine. It would also be fine to have one with, say, a few seeds or two different types of grain, such as wheat and rye. I’d say, though, that as soon as the ingredient list has more than 5 or 6 ingredients, I would not buy it.

Yogurt is another good example. I know, regular fruit yogurt is easy and convenient to have in the fridge, but it’s almost as convenient to just buy plain jogurt, and then add some fruit. Frozen fruit would be just fine, by the way. And if we really need a little bit of sweetness in that yogurt, we are still be better off just adding a little bit of maple syrup, honey, or even sugar at home, or an alternative such as stevia. This would still have a lot less sugar than the overly sweetened commercial fruit yogurts.

Pay attention to the use of ‘natural flavors’ in these commercial yogurts and other ultra-processed foods. They may sound benign, but ultimately, they are a key part of the flavor technology industry to change the flavor of foods at will, which may be a key characteristic of ultra-processed food that makes us overeat. I try to limit these as much as artificial flavors.

Cheese is another good example. Not sure how it happened that particularly dairies in the United States started to add all of this stuff to cheese. None of this is necessary. We just look for a short ingredient list, such as the one below on the left.

As a general rule, if a food is packaged and has more than 5 or 6 ingredients, some of which can barely be pronounced, or that are obviously extracted from whole foods, such as protein isolates, modified starch, high-fructose corn syrup, or mono- and di-glycerides, I think twice before I make a purchase, and at least twice before I eat it. The purchasing decision is maybe the more important one, though, because, let’s be honest, once it’s in the house, we will eat it. And that is particularly true for ultra-processed foods, which have a habit of singing their siren song from the pantry all day.

The last thing worth mentioning that we can all learn from the research discussed in this blog post: eat slowly, and take breaks while you are eating. Eating fast by itself almost certainly contributes to overeating, and that is almost certainly true to ultra-processed foods that seem to make us eat faster.

Key for Health: Keep Ultra-Processed Foods to a Minimum

Just in case this is not clear yet, let me say this explicitly:

To me personally, the introduction of ultra-processing of food over the last 40-50 years is THE single most harmful change in global nutrition that has probably ever occurred.

The epidemiological data show a very consistent and strong association between ultra-processed food consumption and the prevalence of obesity and numerous chronic diseases in populations all around the world. And as we discussed in this blog post, we now have compelling data from a randomized controlled trial demonstrating clearly that people overeat massively when they are served a diet rich in ultra-processed foods.

To me, the totality of the evidence strongly suggests that ultra-processed foods are one of the major causes of overeating, and a key contributor to the worldwide obesity epidemic. 

Note that I am not claiming that ultra-processed foods are the only factor in the global obesity epidemic. Quite obviously, some people overate and were obese well before any ultra-processed foods were ever created. There is no question that if you eat a diet of rich homemade foods, you can still gain weight even if you never touch any packaged ultra-processed foods. But the abundance, convenience, and affordability of ultra-processed foods have made overeating almost inevitable for most people these days. 

The way I see it, most of our food has become an absurd concoction of substances that quite often we can barely pronounce. I honestly think we have let the food industry get away with this for way too long. Can we really be astonished that this massive change in our food supply has had negative effects on our health and our waistlines?

I am hopeful that an improved scientific understanding of the specific mechanisms through which ultra-processed foods make us overeat will gradually pressure the food industry to change these foods to be less detrimental to our health. Until then, the science suggests that we should limit our consumption of ultra-processed foods as much as we can if we want to avoid overeating and weight gain.

I’d like to close with one related, very important issue: ultra-processed foods are fairly cheap per calorie. This often makes these foods the only choice for people with a very limited food budget. This is very regrettable because the shortsighted policy decisions affecting the pricing structure of our food supply are inevitably leading to major costs elsewhere in society, most notably in the healthcare system. If you find yourself in the position that it is difficult to afford fresh unprocessed foods, my suggestion is to focus on bulk whole grains, legumes, dairy foods, and canned or frozen vegetables, and to use fresh expensive items such as fish or meat in small amounts. Buy fresh fruit and vegetables in season, and prioritize whatever is on sale. If you have the space and the time, consider growing some green leafy vegetables, salad greens, or herbs. These are very expensive per calorie, but offer a lot of nutritional value even when added to a meal in small amounts. I remember being a very poor graduate student in Germany about 25 years ago, living on less than $400 per month, so I know how difficult it can be to eat well.

Have you tried to limit your consumption of ultra-processed foods? How difficult was it? Did your food budget, or your time in the kitchen, go up significantly? Did you see any health benefits? I would love to hear from you: please leave a comment below!

Take care!


2 Responses

  1. Dr. Kratz,
    Hi. I just wanted to point out two typos on this page (Ultra-processed foods and weight gain): In the section where you give the ingredients for corn chips, you mention corn “ships” twice.
    Otherwise, thanks for your insightful analysis. Looking forward to your future posts.

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