Ultra-Processed Food: What Now?

Ultra-processed food is such an ugly phrase. Could this friendly little goldfish cracker really be such a threat to health? Defining that threat was the subject of a very collegial, but intense discussion on the closing day of Nutrition 2019 between Kevin Hall and Mike Gibney. But it was hardly confined to that one session. It was a thread that ran through the entire meeting.

At this point, it’s clear that we have a problem with it. There’s smoke and there’s fire. However, it’s not clear precisely where the fire is. What exactly is the problem with this stuff that we’ve defined as ultra-processed food?

More Than Mere Associations

Kevin Hall presented his research that established – for the first time – a clear cause and effect relationship between these foods and weight gain. Before this, it was all guilt by association. However, he was also quite clear that this study raises more questions than it answers. That’s what good research does. It answers specific questions and points to more.

A core question remains unanswered. Why did these ultra-processed foods lead people to eat more calories and gain weight in a short-term setting? Hall remarked that many people wrote him after the study appeared in print. They told him that they knew exactly why he got the result he did. They had very strong feelings. But without additional research, how could they be so sure?

A Problem of Definition

Professor Mike Gibney presented a thoughtful perspective on the problems of defining ultra-processed foods. Should we be focusing on nutrients or ingredients? What about the processing of these foods?

For example, vanilla is a flavor enhancer. Does its use make a food ultra-processed? Regarding the classification of food, RDN Linn Steward is a culinary nutritionist who analyzes foods and recipes for a living. She’s worked with the Nova classification system for processed foods and she tells us:

In my observation, the lines of demarcation are so fluid that there is ample room for disagreements.

The challenges of clearly defining these foods and their issues will only grow more difficult, Gibney said.

Objectivity and Curiosity, Please

Simply demonizing processed foods and implicitly blaming “big food” for obesity will accomplish little. Is the NOVA classification system for ultra-processed foods adequate? Or should we be focusing instead on nutrient density? Will the short-term effects that Hall documented in his tightly-controlled research prove to be robust in longer-term and more natural settings? What is it about these foods might be causing weight gain and health issues?

In a recent post, Julia Belluz lays out the case for these foods causing problems through the microbiome. It’s reasonable speculation. However, you can be sure that if that is part of the problem, the picture will grow even murkier.

Many, many questions remain unanswered. We hope that people will channel their passion for this subject into passionate objectivity. Genuine scientific curiosity about this complex puzzle is essential. Anyone who suggests they have the answers right now is a stranger to the truth.

Click here for Hall’s research and here for his slides. For Gibney’s most recent paper on this subject, click here and then here for his slides.

We gratefully acknowledge the contributions of LeeAnn Kindness in reporting on discussions of ultra-processed foods at Nutrition 2019.

Goldfish Cracker, photograph © Lena LeRay / flickr

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June 12, 2019