by Marion Nestle

Currently browsing posts about: Research

Jan 8 2024

The pushback on ultra-processed: a study (of sorts)

Lots of people are uncomfortable about the concept of ultra-processed foods, the category of processed foods made mainly of industrially extracted ingredients, containing little or no recognizable food, and able to reproduced in home kitchens only if you have the ingredeients and the equipment.

Here is an example: The Guardian headline: “Ultra-processed foods are not more appealing, study finds”

The Study: Evidence that carbohydrate-to-fat ratio and taste, but not energy density or NOVA level of processing, are determinants of food liking and food reward.  Appetite, Volume 193, 2024, 107124, https://doi.org/10.1016/j.appet.2023.107124.

  • Purpose: “This virtual (online) study [highlighted so you won’t miss this point] tested the common but largely untested assumptions that food energy density, level of processing (NOVA categories), and carbohydrate-to-fat (CF) ratio are key determinants of food reward.”
  • Method: “Individual participants (224 women and men, mean age 35 y, 53% with healthy weight, 43% with overweight or obesity) were randomised to one of three, within-subjects, study arms: energy density (32 foods), or level of processing (24 foods), or CF ratio (24 foods). They rated the foods for taste pleasantness (liking), desire to eat (food reward), and sweetness, saltiness, and flavour intensity (for analysis averaged as taste intensity).”
  • Results: Against our hypotheses, there was not a positive relationship between liking or food reward and either energy density or level of processing. As hypothesised, foods combining more equal energy amounts of carbohydrate and fat (combo foods), and foods tasting more intense, scored higher on both liking and food reward. Further results were that CF ratio, taste intensity, and food fibre content (negatively), independent of energy density, accounted for 56% and 43% of the variance in liking and food reward, respectively. We interpret the results for CF ratio and fibre in terms of food energy-to-satiety ratio (ESR), where ESR for combo foods is high, and ESR for high-fibre foods is low.”
  • Conclusion: “We suggest that the metric of ESR should be considered when designing future studies of effects of food composition on food reward, preference, and intake.”I ca

Comment

I can’t say this any better than Stuart Gillespie, who posted:

https://twitter.com/stuartgillesp16/status/1729061409202618512?s=51&t=BTlnSTTeO7_vUXAOw5KNXg

Or Tamar Haspel (@Tamar Haspel) who points out:

Want to find out what properties of food drive consumption?

Is it fat/carb ratio, degree of processing, sweetness?

I’m gonna say asking a self-selected group of internet randos to rate a bunch of really unappetizing photographs isn’t the way.

If nutrition and food scientists want to shoot down the concept of ultra-processed foods, they are going to have to refute hundreds of studies linking such foods to poor health outcome, as well as the carefully controlled clinical trial demonstrating that ultra-processed foods encourage overeating.

If

Dec 13 2023

The red/blue divide in American food choices?

A group with which I was unfamiliar, PropellerFish, sent me a report of a survey it conducted: Partisan Wellbeing in America.

Earlier this year, we sponsored a study to take a more robust look at how partisanship may be shaping people’s decisions around health, nutrition and wellbeing.
We conducted a quantitative survey with 1,400 Americans across the country and further engaged 450 of those respondents in qualitative writing assignments.
We then ran in-home ethnographies with eight participants who epitomized the perspectives we encountered to put that learning into context.

They were particularly interested in the views of people in conservative small towns.  For example:

Overall, foods were perceived as liberal when they:

  • Symbolized privilege
  • Signaled entitlement
  • Were associated with liberal causes (e.g., climate change)
  • Were associated with a liberal place (e.g., California)
  • Is viewed as technologically advanceed

America;s divisions, they conclude, are rooted in distinct world views.

Small town conservatives are concerned that eating healthfully will alienate their peers.

How to fix this?

  • Make healthier choices more accessible.
  • Associate healthier choices with hard work.
  • Connect healthier choices to rural social issues.

I like qualitative research.  It gets at voices and let’s them be heard.

What PropellerFish found here is not particularly surprising, but it’s the first time I’ve seen such views presented so clearly.

Worth a look?  I think yes.

Sep 20 2023

Video time: Plant Chompers on nutrition misinformation

I was induced to watch all of this video because Chris MacAskill, whom I do not know personally but who quoted me a couple of times briefly in a previous show, starts out his investigations by displaying my book Food Politics.  

This is titled, “How Food Myths SPREAD: Fact Checking Dr David Diamond

I don’t know Dr. Diamond either, but he has some unusual and quite strong opinions about nutrition, which MacAskill, a historian, demolishes one after another.

MacAskill checks references, demonstrates the flaws in statements taken out of context, and does so carefully, compellingly, and entertainingly.

This is really worth watching (and I do appreciate the shout outs).

Mar 31 2023

Weekend reading: Nutrition research at NIH

While I’m catching up on items I’ve been wanting to post about I ran across this report from NIH about its nutrition research initiatives. 

NIH Nutrition Research Report 2020-2021

 

Some highlights:

  • NIH’s total investment in nutrition-related research was approximately $2.0 billion in FY20 and $2.1 billion in FY21.
  • Nutrition research funding increased by approximately $510 million—a 25 percent overall increase—from FY14 to FY21
  • Approximately half of the nutritionrelated projects in FY20 and FY21 were related to prevention or obesity.
  • NIH sponsored workshops on Precision Nutrition, Food Insecurity, and Conflicting and Controversial Health Information in the Media
  • Nutrition research comprises just under 5% of total NIH research obligations.
  • NIH sponsored a study in 2021 of  low-fat compared to low-carb diet.
  • A future direction will be to address how “food as medicine” can be improved in clinical settings.

I did not know much of this and am happy to have the report.

The documents

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Mar 30 2023

Teaching critical thinking about nutrition and health resources

A report, Science Education in an Age of Misinformationfrom Stanford University and written by a distinguished group of scientists addresses a question I get asked all the time: how do you know whom to trust when reading articles about food and nutrition.

It presents a decision tree for evaluating information sources.

 

 

 

 

 

 

 

 

 

 

 

 

 

Although most of the report is focused on other science topics, it includes one nutrition example (Example 3, pages 34 and 35).

Example 3 presents two websites, one from the Partnership for a Healthier America, the other from ILSI, the International Life Sciences Institute.

The suggested lesson asks students to use the decision tree to evaluate the credibility of the information on the websites.

For this example,

if students search for ‘Partnership for a Healthier America,’ they will find that one of the first links to appear in the search results is from Wikipedia…they may decide to start with the Wikipedia page to get a broad sense of what other information is available about the organization. There students will read that PHA is a nonprofit organization focused on health and nutrition. Its president and CEO is Nancy Roman, who has years of experience working for world food programs, food banks, and nutrition non-profit organizations.

On the other hand, when students apply the same strategy to the ISLI web page, they are also likely to begin with the Wikipedia entry. This tells a very different story. While ISLI is also a nonprofit organization, the Wikipedia entry shows it was funded by a Coca-Cola executive and has numerous ties to food and chemical companies, such as McDonald’s and Pepsi. Such ties represent a clear conflict of interest and would strongly suggest that ISLI is not a credible source of information.

A good start?  I think yes.  Take a look and decide for yourself.

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Nov 17 2022

Hyping research: coffee

I always appreciate the Headline vs. Study sections of the Obesity and Energetics newsletter that arrives in my email once a week.

This one concerns coffee.  It amuses me that researchers are always trying to prove either that coffee is a superfood or that it is poison.

It’s neither, but never mind.  The research is fun to track.

Headline: Coffee Lowers Risk of Heart Problems and Early Death, Study Says, Especially Ground and Caffeinated.

Researchers found “significant reductions” in the risk for coronary heart disease, congestive heart failure and stroke for all three types of coffee. However, only ground and instant coffee with caffeine reduced the risk for an irregular heartbeat called arrhythmia. Decaffeinated coffee did not lower that risk, according to the study published Wednesday in the European Journal of Preventive Cardiology.

Press-Release: Coffee Drinking Is Associated with Increased Longevity.

Study: Self-Reported Coffee Consumption in the UK Biobank… Again. Causation Not Established.

Drinking two to three cups of coffee a day is linked with a longer lifespan and lower risk of cardiovascular disease compared with avoiding coffee, according to research published today in the European Journal of Preventive Cardiology, a journal of the ESC.1 The findings applied to ground, instant and decaffeinated varieties.

Headline vs Study Déjà Vu: For More Coffee in the UK Biobank Headlines, See Headline vs Study from July 30, 2021.

And just for fun, here’s the Washington Post’s adorable interactive comparison of the relative benefits of coffee vs. tea.

My view?  Drink whichever you like, don’t worry, be happy, enjoy!

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Jun 1 2022

Who funds research on food and agriculture?

The USDA has just released this summary of food research funding.

This graph clearly indicates what I view as a big problem: government funding for agricultural and food research has been declining since the early 2000s, whereas private funding—meaning corporations and industries—has sharply increased since 2008 or so.

What’s wrong with this picture?

Government funding can support basic research with no obvious commercial implications—science.

Funding by food corporations and industries has one primary purpose: to develop and promote products—marketing.

I’m not opposed to marketing research, as long as it is labeled as such.

The decline in federal funding for food and nutrition research has long-term implications for scientific progress.

We need basic research on agriculture, food, nutrition, and health.

These curves need to be reversed.

Apr 28 2022

Annals of food science: Oreo cookies!

After all my complaints about nutrition science, every now and then I hear about a study that just seems perfect.

Thanks to my NYU colleague Mitchell Moss for sending this account of the study:  Age-old Oreo mystery solved by MIT scientists: Can the cream be evenly split between both sides?

The study (published in a physics journal, no less): On Oreology, the fracture and flow of “milk’s favorite cookie. Crystal E. OwensMax R. Fan,, A. John Hart, and  Gareth H. McKinley  Physics of Fluids 34, 043107 (2022); https://doi.org/10.1063/5.0085362

The mechanical experience of consumption (i.e., feel, softness, and texture) of many foods is intrinsic to their enjoyable consumption, one example being the habit of twisting a sandwich cookie to reveal the cream. Scientifically, sandwich cookies present a paradigmatic model of parallel plate rheometry in which a fluid sample, the cream, is held between two parallel plates, the wafers. When the wafers are counter-rotated, the cream deforms, flows, and ultimately fractures, leading to separation of the cookie into two pieces.

Method: Using a laboratory rheometer, we measure failure mechanics of the eponymous Oreo’s “creme” and probe the influence of rotation rate, amount of creme, and flavor on the stress–strain curve and postmortem creme distribution.

Results: The results typically show adhesive failure, in which nearly allw (95%) creme remains on one wafer after failure, and we ascribe this to the production process, as we confirm that the creme-heavy side is uniformly oriented within most of the boxes of Oreos…Failure mechanics further classify the creme texture as “mushy.”

Research iInnovations: We introduce Oreology (/ɔriːˈɒlədʒi/), from the Nabisco Oreo for “cookie” and the Greek rheo logia for “flow study,” as the study of the flow and fracture of sandwich cookies…Finally, we introduce and validate the design of an open-source, three-dimensionally printed Oreometer powered by rubber bands and coins for encouraging higher precision home studies to contribute new discoveries to this incipient field of study.

Multimedia: The study comes with a computer-redered animation demonstrating use of the Oreometer (definitely worth a look).

FIG. 11. This computer-rendered animation shows the assembly and use of our Oreometer including inserting the Oreo cookie into the two halves of the clamping fixture, inserting this fixture into the base, and adjusting the base separation, adding “penny castles” to the wings, adding pennies, and finally observing the fractured Oreo.

The press release: MIT engineers introduce the Oreometer

In all, the team went through about 20 boxes of Oreos, including regular, Double Stuf, and Mega Stuf levels of filling, and regular, dark chocolate, and “golden” wafer flavors. Surprisingly, they found that no matter the amount of cream filling or flavor, the cream almost always separated onto one wafer.

Comment:  Who are these people?  I love their study.  I can’t do justice to it in this brief summary.  Read it.  It’s clearly written, elegantly illustrated, and full of delicious tidbits about the construction of Oreos.

But I do have a question: When trans fats were required to be revealed on food labels, Oreo creme was no longer made with hydrogenated oils.  I think the creme in Oreos was firmer with trans fats.  I’m guessing the “mushiness” is due to higher levels of unsaturated fatty acids.  I think a historian needs to get into this.  Is the unfair distribution of creme collateral damage from making its fats healthier?