It’s time for me to come clean about something you’ll probably see as really dirty — and pretty repulsive to boot. But I’m not about to quote from an old love letter.

I’m about to write about slime, bacterial slime at that. The type that occurs when Xanthomonas campestris is added to a carbohydrate and allowed to ferment.

To create a thicker-than-pudding consistency in a high-protein snack I make and eat about six times a week, I sprinkle one teaspoon of it into each week’s batch before blending all the ingredients together one final time. This slime is sold as xanthan gum.

Chris Van Tulleken, whose book I reviewed and recommended last week, Ultra-Processed People (W.W. Norton, 2023), considers it to be an ultra-processed food.

I regularly write it’s best for you to severely limit your consumption of UPFs, yet here I am — admitting to adding one to something I’ve suggested you try for yourself in a past column.

This is not a case of hypocrisy, however. Instead, it’s an example of why the column that follows needs to be written.

Currently there’s no consensus about where to draw the line between processed and ultra-processed foods — even though most in the first group provide safe and healthy sustenance and most in the second don’t. Moreover, the definition used in the 2010 groundbreaking study that coined the term ultra-processed food is a mind-numbing 80 words long.

So Van Tulleken explains UPF in his book this way: “Much of it will be familiar to you as ‘junk food,’” but it’s much more. “If it’s wrapped in plastic and has at least one ingredient that you usually wouldn’t find in a standard home kitchen, it’s UPF.”

He later jokes that normally you only find Xanthomonas campestris in your kitchen as “accumulated gunk” on the filter of your dishwasher. I’m sharing that I ingest this “gunk” to illustrate a nutritional catch-22.

Let’s say you want to adopt the popular eating philosophy designed to give you some dietary abandon without harming your health: To eat good food 80 percent of the time and not-so-good the other 20. How you can you follow that philosophy without knowing which foods fall into which category?

To muddy the waters even more, a recent opinion paper published in the European Journal of Nutrition suggests that UPFs according to the 2010 definition of them may not be the “real culprit” because that definition is too broad and “unspecific.” That limiting or avoiding foods to adhere to it is “scientifically weak.”

Moreover, the paper argues “different groups of UPF evaluated within the same epidemiological study often show markedly different associations with the incidence of the health endpoints.” In other words, when it comes to consuming UPFs and how they affect your health, don’t confuse the clearly bad ones with the possibly good or the no-worse-than-neutral ones.

Don’t see consuming highly processed meats and sugary drinks as the same as eating canned baked beans or chili — or processed foods that contain additives like carrageenan, locust bean gum, guar gum, and (yes) xanthan gum.

In the Medical News Today article by Finn Cohen “Are all ultra-processed foods equally bad for health?,” Cohen enlists the help of a Melanie Murphy Richter, MS, RDN, a registered dietitian nutritionist and the director of communications for the nutrition company Prolon, to cut through the confusion.

After Richter acknowledges many UPFs have been linked to an increased risk of chronic disease, she notes “some can have neutral or even beneficial health effects.” She then offers that this opinion paper “underscores that not all ultra-processed foods are created equal, and grouping them together as universally detrimental is overly simplistic.”

Those two final words underscore the best way to end this article: with a helpful suggestion that’s just that.

So I’ll be overly simplistic and suggest you start reading nutritional labels the way you reread old love letters you treasure.

You need to read them that closely because you need to be on the lookout for added fats and sugars — and the sugars are not always easy to find.

While the FDA mandates all ingredients be listed in descending order of weight, they allow for 60 different names for added sugars. So one underhanded strategy is to incorporate as many different sugars as possible in a UPF so a single one doesn’t appear first or second on the list.

For the reason you don’t want to consume UPFs containing both sugars and fats, consider the conclusion of a paper published by the British Journal of Medicine in October 2023. That when eaten in tandem, sugar and fat have a “supra-additive effect on brain reward systems, above either macronutrient alone.”

In laymen’s terms, that means the UPFs containing both are addictive, really addictive — as addictive as alcohol, in fact.

Occasionally eating certain UPFs is one thing. Getting hooked on the worst of them is another.