Just Read: Evaluating the environmental impacts of dietary recommendations (what is the impact if “recommended” and “healthy” aren’t the same in an era of diabetes reversal)

Continuing my exploration of what a sustainable diet is in the context of overall health, this paper looks at nationally recommended diets around the globe and the impact on the environment of those recommendations actually being followed.

In the United States, for example, there has been a long-standing recommendation, starting in 1961, to reduce fat intake below 30% and saturated fat below 10% of calories, which has actually resulted in an increase of carbohydrate intake, and no significant reduction in fat intake.

In this post, I showed what it looked like from the archives of US News and World report, when a photographer visited the “harried housewife at home eating convenience foods” – American diets were re-engineered with less fat and more carbohydrates, with success (unfortunately).

More from my trip to the Library of Congress and incredible US News and World Report photo collection: 1968’s Harried Housewife Preparing Convenience Foods (and how her diet was re-engineered to be carbohydrate-rich)

What I learned here:

  • National Dietary Recommendations vary widely across the globe. In middle to lower income countries there’s a recommendation for more calories, more animal products in some cases (India and Indonesia) in the setting of malnutrition, the opposite in the United States.

Compared with average national diets, NRDs generally recommend a substantial reduction in sugars, oils, meat, and dairy

  • Moving to a plant-based or animal-based diet has different environmental impacts in different countries due to differences in food production systems

Although not as extreme, the United States, Canada, and Norway have emissions 40% higher than the average of their income group, with meat, dairy, and fish contributing larger amounts than the average, respectively. In the United States and Canada this is also likely due to grass-fed cattle; in Norway, fishing contributesmore than in other regions, due to both demand and fuel-intensive fleets.

  • The types of carbohydrates, fats, and proteins eaten vary wildly across countries

There’s an Excel spreadsheet published in the supplementary material that has a wealth of data about the actual intake per capita of discrete types of foods. Look especially at intakes of engineered seed and bean oils (eg soybean). These effect significant changes in health, so it’s not easy to say that a country that has a higher or lower fat intake has a healthier diet just based on this percentage.

The challenge of this analysis, conflating “heatlhy” with “recommended”

Unfortunately, from my read, the analaysis conflates “healthy” with “National Recommended Diet,” and we now know in the United States, for example, that the evidence base for the low fat diet is problematic or non-existent.

This is an example of this conflation:

However, as these nations undergo the nutrition transition whereby diets shift from plant-based staples to an increased intake of animal-based and processed foods, this may result in situations where undernutrition and obesity can coexist (commonly termed the double burden ofmalnutrition)

“Animal-based” and “processed foods” are not the same thing. Any more than “plant based” and “unprocessed foods” are.

Here’s another example of conflation:

South Africa has historically suffered from a high prevalence of undernutrition but, after several decades of transition, now has a high rate of obesity due to a shift to a diet high in fat, simple sugars, and animal-based foods.

As described in this book (Just Read: Tim Noakes and Marika Sboros – Lore of Nutrition: Challenging Conventional Dietary Beliefs) the issue was less fat and animal-based foods and more simple starches that are cheaper to produce and have limited nutritional value, and were recommended as staples in the diet.

The paper also does not do a full lifecycle analysis of greenhouse gas emissions of recommended diets, which may increase GHGs because they are more diabetogenic than “non-recommended” ones. (see: Just Read: Do low-carbon-emission diets lead to higher nutritional quality and positive health outcomes? A systematic review of the literature.)

Or as @RobertLustigMD recently tweeted

I’m interested in this because

  • Climate change is a risk to human health.
  • Climate change increases disparities because it disproportionally affects vulnerable populations.
  • Diversity allows the human species to survive 🙂
2017.12.12 Sustainable Diet, Washington, DC USA 1359
What’s better for human health, the products in the foreground, or the products in the background? | 2017.12.12 Sustainable Diet, Washington, DC USA 1359 (View on Flickr.com)

Comments and additional teaching always welcome

Citation

Behrens P, Kiefte-de Jong JC, Bosker T, Rodrigues JFD, de Koning A, Tukker A. Evaluating the environmental impacts of dietary recommendations. Proc Natl Acad Sci [Internet]. National Academy of Sciences; 2017 Dec 19 [cited 2018 Jan 9];114(51):13412–7. Available from: http://www.ncbi.nlm.nih.gov/pubmed/29203655

Discussions on social media

This paper received some, but not a lot of attention on social media: Altmetric – Evaluating the environmental impacts of dietary recommendations

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