I enjoyed your round-up and appreciate your concerns. I am coping with the pain and confess to being ultra-exhausted, but I will survive. I think that our dialog is producing fruit. I found three statements that you made in the round-up with which I can agree and two that trouble me. Let’s start with where we agree:
1. the main take-away is that calories do matter to weight gain
After reading so much about how some calories are more equal than others, i.e. processed calories are worse for us than unprocessed ones, it is nice to get some verification of the importance of calories. Basically, it would appear that the participants ate about 250 calories a day more than they needed to maintain weight on the ultra-processed diet and those on the unprocessed diet ate about 250 calories too few. You don’t seem to value maintenance of a healthy weight, but it is the goal of any of any weight program to achieve and then maintain a healthy weight.
2. These days any diet in a halfway-advanced economy is bound to be mixed to some extent. What matters is the relative proportions.
We also seem to agree that a balance of ultra-processed and with unprocessed/minimally processed foods is OK. I suspect that my ideal balance would look different from yours, but mixes are inevitable if not desirable. I would like to see fewer internet stories telling people to avoid ultra-processed products and using scare tactics against specific foods when they happen to be in the class, but I will not hold my breath! For example the NOVA group is still encouraging us to minimize processed and avoid ultra-processed food.
3. Arguments about the cost of eating a minimally processed diet, in specie and in time, have a lot going for them.
Access to fresh foods and the ability to prepare home-cooked meals is of real concern as described in depth in Pressure Cooker: Why Home Cooking Won’t Solve Our Problems and What We Can Do About It. I plan on devoting the month of August to food access and such terms as food deserts, food swamps, food apartheid, and grocery gaps on my blog. September will feature a review of Pressure Cooker and a look at food slopes with an aim at where processed and ultra-processed food might fit into the cause of food justice.
Here is where I have the most problems with the NOVA classification system and your take on it.
1. And the more ultra-processed food the greater the chance of dying.
This is a comment you make with respect to the BMJ study. I like that you point out the problem with confusing correlation and causation, but your statement above serves to imply causation. I think that there is cause to be concerned about the potential health effects of ultra-processed foods, but the category is so broad in the World Nutrition article (http://archive.wphna.org/wp-content/uploads/2016/01/WN-2016-7-1-3-28-38-Monteiro-Cannon-Levy-et-al-NOVA.pdf), that it is impossible to determine which ultra-processed foods are unhealthy and which ones are not, OR are they all unequally unhealthy? How is some single-mom with limited access to fresh foods, limited money to buy food and limited time to prepare it supposed to know which convenience foods available are least damaging to her children? More reason to clarify which subcategories of ultra-processed foods are more unhealthy than others.
2. “Ultra-processed” is all about how it has been processed and how much it has been processed. And nowhere in the most recent explanation of the NOVA food classification and the trouble with ultra-processing is the number of ingredients considered important.
Talk about bait and switch! It is apparent that the authors have responded to those critics of the NOVA classification scheme by changing the definitions. Political viewpoints and organisms evolve, but scientific definitions should not. It then becomes very difficult to compare one study with another. For the most part the classes remained relatively similar, the processes and classes of additives associated with ultra-processing are clarified, but the list of ultra-processed products has become smaller and much vaguer. A cynic would argue that by providing fewer targets, it makes it harder to challenge. BTW, Gibney has a recent article which describes the eight modifications of the classification scheme since 2009. It is true that the version I find at https://www.cambridge.org/core/journals/public-health-nutrition/article/un-decade-of-nutrition-the-nova-food-classification-and-the-trouble-with-ultraprocessing/2A9776922A28F8F757BDA32C3266AC2A/core-reader and nicely summarized at https://world.openfoodfacts.org/nova does not list the number of ingredients as you state. It only lists, however, five unacceptable processes—hydrogenation (no longer allowed in the United States), hydrolyzation, extrusion, moulding (does that mean no homemade cupcakes from scratch?) and pre-processing for frying (such as breading—again what about deep-fat frying at home?). Those represent very few of the myriad of processes used in food manufacturing. The article singles out 32 classes of additives that when present make it an ultra-processed product. I still believe that ultra-processing is primarily about ingredients, at least the types if not the number. Food formulation, which is mentioned in the latest NOVA classification, is the mixing of ingredients. I think the term ultra-formulation would be much more appropriate than ultra-processing. Somehow, distilled spirits no longer seem to be ultra-processed. I am now not sure if whole-grain breads or protein bars or a veggie pizza have been given a reprieve. In the World Nutrition version of NOVA, it appeared that fortification with vitamins and nutrients made a product ultra-processed, while the later version is less clear.
Finally, a clarification on the milk issue:
At no point does the Hall et al. paper say that one diet was exclusively unprocessed or exclusively ultra-processed.
You accurately pointed out that the ultra-processed had partially skim milk (2% fat) for dinner on day 7 in addition to whole milk for breakfast on day 1. I missed that. Thanks for pointing that out. No whole milk was offered on the unprocessed diet, but they received skim milk five of the seven days, as you also indicate. In Table 1, however, the article states that 4.6% of the energy (calories) on the ultra-processed diet came from unprocessed foods (presumably from the two servings of milk) and that 0% of the energy (calories) in the unprocessed diet came ultra-processed foods. It is not clear where the 17% or so of the calories come from if they are neither unprocessed nor ultra-processed.
I hope that this is not the end of our discussions, I welcome any comments from you and your readers or on my blogsite, https://processedfoodsite.com/ My latest post highlights seven statements I consider highly misleading about ultra-processed foods and three I consider rational. Note that I was operating on the earlier version of the classification scheme in my posts this week as were you in the initial newsletter on the topic.