Tag Archive for: UPF

Where’s the Proof?

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A series of articles and studies published recently have called into question the use of statistics in examining large health databases. It’s especially pertinent to nutrition research because placebo-controlled trials are virtually impossible.

See if this sounds familiar: eating meat is associated with an increased risk of colorectal cancer. The “association” is calculated by considering variables that may impact the development of cancer and estimating the hazard of eating various quantities of meat. Recent articles have called into question whether enough variables are being considered, because only a few people decide what else could impact the development of cancer other than meat. Then the analysis is run and the results reported.

What if they didn’t pick the correct variables or enough variables that could impact cancer? What if they didn’t use the correct statistical methods to analyze the data? That could be why one study shows fish oil lowers the risk of cardiovascular mortality and another says it does not. Let’s look at an example.

“Ultra-Processed Food is Bad”

Eric Schlosser is an author and filmmaker who wrote Fast Food Nation and made the movie Food, Inc.; Food, Inc. 2 has come out recently. As a guest on Real Time with Bill Maher, he commented that ultra-processed food (UPF) is the leading cause of obesity and other diseases, but he offered no evidence to support that position. He suggested that it was the artificial ingredients found in UPF that make us crave them and eat them without restraint. Again, no evidence.

Several epidemiological studies have suggested that UPF is related to obesity. The question that remains is how? If it’s the artificial ingredients, how do they do that? By stimulating appetite? Or turning off satiety signals? Or some other mechanism?

That data isn’t collected in most large studies. When the researchers select variables that could impact the results, are they considering the correct ones? It makes a difference because at the end of these large observational studies, that’s the question that remains: How?

The Bottom Line

There is no conclusion at this point. That’s not usually my style, but this is complicated. There are too many observational studies and meta-analyses that are being used as the foundation of medical care and health and nutrition education, because as I see it the data are incomplete. For now, there are some changes we know will work and can prove: Eat less. Eat better. Move more.

What are you prepared to do today?

        Dr. Chet

The Final Question on Ultra-Processed Food

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Here’s what we found out so far: When we eat ultra-processed food (UPF), we tend to eat way too much of them, upwards of 500 more calories per meal. We absorb more of those calories; the absorption starts sooner in the small intestine because of the simple carbohydrates in the UPF. Finally, we found out that we do not lose as many calories in our stool as we would if we had more fiber and more resistant starch in our foods.

But we need to answer one more question.

Is a Calorie Just a Calorie?

Despite the research that’s been done, all the clinical trials on UPF are on small groups of subjects. I’d like to see one more study similar to the one comparing the microbiome-beneficial diet with the Western diet high in processed foods. If researchers could do the same study on a group of overweight people and put them on one of two calorie-restricted diets—one following the microbiome-beneficial diet while the other used an ultra-processed food diet—we could see if there were differences in weight loss and other health markers between the two groups. Then we’d know whether there were any real differences between the types of calories we put into our bodies.

When thinking about weight loss, I always go back to the Minnesota Starvation Experiment. The subjects, all conscientious objectors, were given only the foods that would be available after WWII in war-ravaged Europe: bread, potatoes, and other root vegetables, little to no protein, and little fat. Normal-weight men lost weight and continued to do so for the entire six months of the study. If it’s just about the calories, then substituting UPF for the starvation diet and adjusting it on a weekly basis would get the same results today. But I don’t see that study happening any time soon.

Are UPFs Healthy?

Not in my opinion because of what they don’t have. No fiber. No resistant starch. No phytonutrients. Then add artificial flavors and colors and throw in sodium and umami flavoring to make us want to eat more of them. No, I don’t think they’re healthy. But if they’re a part of a total diet and consumption is controlled, then, while the research is not in yet, a calorie could be just a calorie.

The Bottom Line

It’s easy to be a demagogue and condemn UPFs as so many others have, but remember that protein powder is a highly processed food, whether from animal or plant sources. So is stevia, the “natural” sweetener. How about almond milk? Have you ever seen an almond teat? Neither have I.

What we need for good health today, not in 1900, 1930, 1950, or even 1970, is a balanced approach to nutritional intake. It’s as simple as eat better, but not perfect. Eat less, but don’t starve yourself on foods you don’t enjoy. And move more. It’s as simple as that.

What are you prepared to do today?

        Dr. Chet

Reference: https://doi.org/10.1038/s41467-023-38778-x

Ultra-Processed Foods: Losing Calories

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In our examination of the research on ultra-processed food (UPF), we’ve found out that we consume more calories and that we absorb more calories if we eat UPF. The final question is probably going to seem a little unusual. Do we actually lose more calories if we eat less UPF? In other words, do we actually eliminate calories if we eat a diet favorable to our microbiome? This is really interesting: we may actually not absorb every calorie we consume! I must admit that this one surprised me; I didn’t realize that we lost calories in our stool under healthy conditions.

Researchers wanted to test whether diet could influence the number of calories lost in feces among a variety of other variables. The researchers recruited 17 healthy, normal-weight to overweight men and women with an average age of 31. They designed a diet that could enhance the microbiome by feeding the healthy microbes that reside in the colon. They matched the diet for percentages of calories and macronutrients with a Westernized diet. The major difference was the fiber content and level of resistant starch; the Western diet included more highly processed foods.

At different points in the study, on both types of diets, they measured the exact calories consumed, calories used in exercise, rest, and sleep, and collected all urine and stool for 24 hours. The most interesting result was that the microbiome-friendly diet increased the calories lost in the stool by an average of 116 calories per day. The bacteria were using the fiber and resistant starch to manufacture more metabolizable calories, but they were lost in feces. They weren’t absorbed, so those calories do not apply.

What does it all mean? More than that, what is the question that hasn’t been answered by any study on ultra-processed food? I’ll cover that on Saturday.

And here’s one more reason to limit UPF, according to an article in the Washington Post: “…eating more pro-inflammatory foods, such as processed meats or sugary sodas, was associated with a higher risk of fecal incontinence. The authors hypothesized that pro-inflammatory foods could have negative interactions with the gut microbiome and diminish the function of the muscles and nerves of the pelvic floor.”

What are you prepared to do today?

        Dr. Chet

Reference: https://doi.org/10.1038/s41467-023-38778-x

Are Ultra-Processed Foods Absorbed Faster?

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The next question to consider with UPFs is this: Do you absorb more calories from UPFs than you would from minimally processed food? The answer appears to be yes, but requires some explanation.

Keep in mind that UPFs have been mechanically and chemically altered during the manufacturing process. The original grains of wheat, corn, or even something such as carrots bear no resemblance to their original form. The components, especially the fiber, have been torn apart. What’s the big deal? The normal chemical bonds that make up the food matrix are no longer in the same form as they were. Therefore, they require less digestion and potentially can be absorbed much faster starting in the small intestine.

That can mean a couple of things. The higher the proportion of UPFs in the diet, the more calories from carbohydrates can enter the bloodstream and get there faster. Blood sugar goes up more quickly; if the calories aren’t immediately used, the extra calories can be converted into fat for storage, and don’t we all love that!

It also means that the food that could have fed our microbiome is no longer present—we’ve taken in plenty of calories, but our microbiome is starving. What nutrient is missing? Fiber in the form of resistant starch. What does it resist? Digestion and absorption. That’s the food for probiotics in the microbiome, and without it, our microbiome is starving and not as healthy as it could be. The more UPFs you eat, the more you need a fiber supplement.

There is one more question that needs to be addressed, and I’ll do that in the next Memo. In the meantime, how about a bowl of steel-cut oats, bean soup, or a nice salad? Your microbiome will be so happy!

What are you prepared to do today?

        Dr. Chet

References:
1. https://doi.org/10.1016/j.cmet.2019.05.008
2. https://doi.org/10.1038/s41467-023-38778-x

Research Update: Ultra-Processed Foods

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Ultra-processed food (UPF) has been in the news again with several research papers published in the last few months. After I read the press releases as well as several articles by health columnists, I found and read the research papers. I’ve narrowed it down to three questions about UPFs plus my own question, which I’ll save for the final memo in this series.

Let’s begin with a working definition of ultra-processed foods: substances extracted from foods that are altered chemically or mechanically, combined with flavor enhancers and other additives, and formed into consumer products that are highly palatable. They are generally high in calories and appeal to every taste sensation humans possess. The manufacturing techniques themselves can change the structure of the original component and include extrusion, molding, and preprocessing by frying. Simply stated, UPFs are designed to be irresistible to eat and keep eating; if you’ve ever been handed a bag of Cheetos, you know what I mean.

The first question is simple: Do UPFs in the diet contribute to an increase in calorie intake? The answer is yes. Population studies of nutritional intake have demonstrated that countries where UPFs are available show additional caloric intake when compared with people who have low intake of UPFs. These studies are based on food frequency questionnaires, which are not my favorite way to analyze diets, as I’ve said repeatedly.

However, the increase in caloric intake in well-controlled studies where people are offered a UPF-based diet was found to be up to 500 calories per day more than on a diet that doesn’t contain UPF foods. It seems clear that eating UPF foods can result in extra calories. I’ll tackle the next question on Saturday.

Tomorrow night is the Insider conference call. If you want to participate, simply sign up as an Insider no later than 8 p.m. Eastern Time.

What are you prepared to do today?

        Dr. Chet

References:
1. Food Funct. 2016 May 18;7(5):2338-46. doi: 10.1039/c6fo00107f.
2. Food Funct 2017 Feb 22;8(2):651-658. doi: 10.1039/c6fo01495j.3. https://doi.org/10.1016/j.cmet.2019.05.008