Dog with Sausages

Digging Into a Squishy Definition for Ultra-Processed Food

Everyone was ready to head home from FNCE 2019 yesterday morning. Yet a crowd gathered to hear from Kevin Hall and Amber Courville about ultra-processed foods. Theirs is the fascinating study that shows people eat more calories and gain more weight on a diet of processed foods. It’s a study that seems quite important. But for many reasons, people are still arguing about what it means. One of those reasons is the rather squishy definition for ultra-processed foods.

The NOVA Classification System

For their study, Hall and Courville used the NOVA definitions to establish what counted as an ultra-processed food. The NOVA system divides foods into four groupings. Group 1 is unprocessed or only minimally processed. They might be whole, natural foods like a fresh fruit or vegetable. They might be minimally processed by cleaning, prepping, freezing, or otherwise processing them without adding anything.

Next, Group 2 is processed culinary ingredients like spices and cooking oils for cooking. Then Group 3 is processed foods with relatively few ingredients. The processing might be cooking, canning, or fermentation, perhaps with simple preservatives.

Finally, Group 4 is where our focus lies. These are the ultra-processed foods. They are industrial formulations with at least five and often many more ingredients. They use industrial food ingredients seldom or never found in home cooking. The whole point of all these ingredients is to imitate the sensory properties of Group 1 foods on an industrial scale of mass production.

On one hand, this classification system is relatively straightforward and objective. On the other, it lumps some rather dissimilar products into the dreaded ultra-processed group. Cheerios, bagels, cream cheese, and hot dogs can all qualify.

Questions to Resolve

Hall and Courville worked hard to make the ultra-processed and unprocessed diets they tested very similar – except for the processing. But it was not easy. They kept macronutrients – carbs, fats, and protein – the same. They tried to keep fiber the same, even though ultra-processed foods typically have much less fiber. Because of that they wound up adding fiber to some of the beverages in the ultra-processed diet. That way people in both groups got just as much fiber. But they got it in different ways.

Was it less fiber in the solid food that made a difference? Or perhaps it was energy density and texture that led people to eat more calories and eat them faster on the ultra-processed diet. The answer will lie with further research. If they hold these factors constant and the differences disappear, then we’ll have better answers. Hall and Courville are already working on it.

In the end, what’s important is to dig into this squishy definition of ultra-processed foods. Many different factors could be driving the problems with them. If research can sort it out, then we’ll have important insights for a healthier food supply. Ultra-processed foods are unlikely to fade away. So perhaps they can be improved.

Click here for the slides for Hall and Courville. For the study, click here. Then here and here you can find further debate about it.

Dog with Sausages, painting by Wilhelm Trübner / WikiArt

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October 30, 2019