A dialogue between a dietitian and a food scientist on avoiding ultra-processed foods  

It’s time for another dialogue between Linn Steward and me on ultra-processed foods. I view Linn as a dietitian who avoids most ultra-processed packaged food, loves to cook, sometimes goes rogue, and likes to ask questions. She views me as a food scientist who defends food processing, has an open mind, loves debating, and likes to teach. It is clear that we are not prototypes for our station in life. We have come to an appreciation of each other’s views on the matter. We don’t agree on many aspects of food, but we respect each other’s viewpoint. Is there hope for dialogue between food scientists and nutritionists/dietitians? Below are some questions I asked her, her response, and my rebuttal:

Q. Are all ultra-processed foods bad or are some worse (or better) for us than others?

Linn: We need to break down the category of ultra-processed foods into smaller pieces before we can answer this question. There are significant differences. For example, some ultra-processed foods have balanced nutrition and others are indulgent with excessive amounts of added sugar, salt, or fat. Some are made with intact foods and others are manufactured with substances extracted, isolated, or derived from foods.

Rob: We are in agreement. The category of ultra-processed foods is much too broad to study as a group. There are too many differences in food composition and nutritional quality. I understand your concerns about ingredients extracted, isolated, or derived from foods. I do not share those concerns.

Q. Are diet sodas as bad for us as sugared sodas or are they even worse?

Linn: It seems to depend on which set of research is used so it’s not a straightforward question to answer. What is certain however is that water is healthier than either sugary drinks or artificially sweetened drinks.

rows of diet and sugared sodas on a grocery store shelf
Are diet sodas better or worse for us than sugared sodas?

Rob: The evidence against artificial sweeteners is much weaker than the evidence against sugar. Are we to avoid fruit juices too? If you try to take away all sweet beverages, then most Americans will rebel.

Q. Can we have an ultra-processed food on occasion or should we avoid them altogether?

Linn: Assuming that an ultra-processed food or drink is a product that has been formulated from ingredients resulting from industrial processes, the percentages I’ve heard are between 15% to 20% calories with the rest of the daily calories coming from minimal, culinary, and traditional processed foods. Freshly prepared meals require someone cook on a regular basis. And cooking requires time, means, and skill. This goal of 80-85% freshly prepared meals is at best challenging and more likely just unrealistic. Brazil, Uruguay, Ecuador, Peru, France, Canada, and Israel are countries that have made changes to their national dietary guidelines to limit the consumption of ultra-processed foods however.

Nutrient reformulation won’t address the problem, but reformulation with whole food is worth exploring.

Rob: More than 50% of food in America cooked fresh is unrealistic and unsustainable. Too many Americans are food insecure and unable to prepare fresh meals on a regular basis. There is not enough fresh food to meet demand. There are not enough farmers to grow all these fresh foods. Local farming and distribution are not options. Expect more industrial farming in the Southwest and Midwest. That leads to more transnational shipments and more food loss. It is a recipe for mass dissatisfaction, mass hunger, and mass food waste.


Q. Why is it all right to continue to eat bacon and ham (processed foods) but not pepperoni, sausage and luncheon meat (all ultra-processed).

Linn: Traditionally cured meats are cured using salt. I haven’t done enough research yet to understand the role of nitrates/nitrites. It’s my understanding that artisan curing is considered Group 3 whereas other technological processed are considered Group 4. It’s also my understanding that nitrites whether a result of salt curing or more sophisticated industrial processing are considered a risk and should be limited.

Rob: I’ve tried to eat salt-cured meats. It is still sold as a delicacy in Georgia. They are terrible! One small piece of meat will exceed the daily value of sodium. Bacon and ham are now offered as uncured meats. Uncured meats means that they use celery salt, which is high in natural nitrates. These uncured items are unsafe from the potential of both botulism and nitrosamines. I have cut back on cured meats, but I have not eliminated them from my diet.

birthday cakes on display in a supermarket
Selecting a birthday cake


Q. What can we serve at birthday parties since ice cream and cake (cake mixes are ultra-processed) are considered to be unhealthy?

Linn: A compelling reason for taking the problem of ultra-processing seriously and promoting a better understanding of the terminology is illustrated by the outrage generated by birthday celebrations. It’s an emotional issue and that means it’s great for clickbait generated social media outrage.

Putting the issue into a serious context means stepping back and having a discussion. Eating ice cream and cake everyday has always been considered imprudent. Having occasional celebrations has always been considered acceptable. I’ve never really understood why some folks want to make so much noise about an issue that is so clearly settled with a little common sense. Purists always have the option of making birthday cakes from scratch and churning ice cream the old-fashioned way with cream and sugar.

Rob: I have no qualms of eating ultra-processed foods as a part of a balanced diet. The uproar over a little ice cream and cake is silly in my estimation. An overindulgence in sweets in the workplace is a more serious problem. Monthly birthday celebrations and sweets from home are workplace hazards. Add to them snacks at meeting breaks and we see the fattening of America. Dairy desserts are the third leading source of calories among senior citizens.

Q. How can Americans celebrate Independence Day if we are discouraged from serving hamburgers, hot dogs, pizza, ice cream and soda?

Linn: Same answer as above. It’s what you do most days that counts.

Rob: Special foods on special days are fine. It is all about the diet not about individual foods eaten on special occasions.

Q. Are we out of luck if we don’t have time or the money or the skill to cook all our own meals?

Linn: Yes. And that is opportunity for food manufacturers to explore.

Rob: Many Americans are food insecure and are not able to cook their own meals. They need convenient meals. Food formulators cannot produce healthy and stable foods without additives in their toolbox.

Well, we seem to disagree on more topics than agree on. But it is a start. We accomplished the exercise without profanities or trash talking. Let’s see if we can continue the conversation in a civil manner.

BTW, check out Linn’s site for more of her perspective on ultra-processed foods. She also introduces us to some gourmet delights.

Next week: How important are intact ingredients in the healthiness of foods?

5 thoughts on “A dialogue between a dietitian and a food scientist on avoiding ultra-processed foods  

  1. HMM = How Much Matters.
    Q. How can anyone talk about foods/bevs without dealing with quantity and why we avoid it?
    A. Because we eat/drink for many reasons beyond biological, and we use and often need and defend images to direct our actions.


    1. Dietitians are focused on nutrients and limiting calories. Food scientists and dietitians view foods from different perspectives. It is crucial that people from the two professions communicate. Food journalists, many of whom have little or no background in either field are setting the agenda, Dietitians and food scientists need to find common ground or the journalists will divide and conquer us.


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