A discussion of: “Global Sustainability (health, environment and monetary costs) of Three Dietary Patterns: Results from a Spanish Cohort (the SUN project)”
The CDC reports that over 40% of American adults are obese, which means a BMI of 30 or higher.
Now, we can argue about the BMI as a metric, but it does show that the number was 30% in 2000 and 40% in 2018. It is definitely capturing a trend, and a bad trend at that.
The CDC also points out the harm obesity causes.
Obesity-related conditions include heart disease, stroke, type 2 diabetes and certain types of cancer that are some of the leading causes of preventable, premature death.
Fresan, Martinez-Gonzalez, Sabate, and Bes-Rastrollo (2018) inquire about the sustainability of our diet by comparing 3 different dietary patterns.
Western Dietary Pattern (WDP) is what we often refer to in the US as the Standard American Diet, which I think has the fitting abbreviation, SAD. But I will use WDP as the authors have.
WDP is described as “nutrient poor energy dense” and is “rich in highly processed and animal-based foods.” (p. 1)
The authors compare WDP to Protovegetarian Dietary Pattern (pVD) and the Mediterranean Diet (MeD).
You can probably already guess which one comes in last place when comparing them for health outcomes, but the authors do not stop there.
They also compare each diet by their environmental costs and the monetary costs to the consumers.
It makes answering the question “which diet is best?” more complicated but also more meaningful.
After all, is eating a diet that costs the least cheap when in the end you pay much more in health care costs and environmental damage?
The Study
The authors are using data from an ongoing study composed of Spanish university graduates, the SUN cohort, which started in 1999 and collects data with a Food Frequency Questionnaire every 2 years. (p. 2). In total, the authors have data for 18,429 participants.
They use the data to estimate daily food intake for each participant using the reported frequency of consumption of 136 food items and the specified portion sizes.
This consumption data is then run against the 3 dietary patterns and divides the people into quartiles that capture how well they are adhering to each pattern.
This allows the authors to examine how the outcomes for those who most adhere to a particular dietary pattern compare to those who most adhere to another pattern.
Defining the Dietary Patterns
The WDP is a diet more heavily focused on “fast food, fatty dairy products, red and processed meat, potatoes, industrial bakery, sauces, precooked foods and sugar-sweetened soft drinks.” (p.2)
The pVD is a diet that skews more towards plant origin food than animal ones. (p. 2)
The MeD is a diet the authors acknowledge could be seen as a sub-type of pVD. (p. 6) Both include a lot of fruit, vegetables, beans, grains, nuts and seeds. MeD, however, specifically focuses on olive oil as the main source of fat.
The authors note the distinguishing features of the MeD include
- a moderate to high consumption of fish and seafood,
- a moderate amount of red wine, and
- a low intake of meat and dairy products
The Results
Each diet is explored across the 3 dimensions: health, environment, and monetary costs.
Health
Outcomes for health are estimated using the Rate Adjustment Period (RAP). (p. 3)
RAP is new to me but it sounds like a common measure in these health/epidemiological studies.
It sounds like it takes in account the likelihood of disease occurring in a population as it ages. Then you compare how your population that was exposed to the issue you are investigating is better or worse than the unexposed population.
The RAP is a method that measures the time by which a rate of a specific outcome is advanced (positive values for detrimental exposures) or it is postponed (negative values from protective exposures) among exposed subjects compared with unexposed individuals, conditional on being free of that outcome at the baseline age. (p.3)
They found those in the quartile that adhered the least to the WDP was negative and increased to slightly positive for the 3rd quartile and even more for the 4th quartile. (p. 7)
Translation: those who do not eat the WDP have better health while the closer you follow the WDP the more detrimental exposures lead to more disease occurring before it should when compared to the general population. This includes diseases like cancer, Type 2 diabetes, and cardiovascular disease.
Both pVD and MeD show that the closer you are to adhering to either diet, the more negative is the RAP — which means you are getting diseases slower than the general population.
MeD showed a RAP (-3) twice as large as pVD (-1.4). (p. 7) Both are good, but something or somethings that define the MeD seem to be more protective of our health than the pVD.
Environment
For environmental impact, the authors created an index for each food consumed so you could have a score for each diet based on the foods it includes.
They used an index method previously used elsewhere along with data from other research groups. (p. 3) The goal is to get a measure of how the environment is impacted in multiple ways,
- land,
- water
- energy and
- GHG emissions
This time pVD wins although again it is similar to MeD. One of the main ways they differ environmentally is fishing, which likely explains the higher negative environmental score. Perhaps this could be addressed with more focus on sustainable fishing practices. (p. 6)
Monetary Costs
Finally, WPD wins the monetary costs. The MeD is the most expensive of the 3 dietary patterns costing 1.42 euros per day more ($1.67 more per day as of today’s exchange rate). That is about $600 a year or $50 a month. The pVD is approximately in the middle of the two.
Conclusion
To sum up,
- MeD is the healthiest
- pVD is the most environmentally friendly
- WPD is the cheapest in monetary costs
The cheap WPD diet may be light on the wallet, but we see from this study it comes with high environmental and health costs. Thus, it may be time to reexamine our food policy that is encouraging the production and consumption of low nutrient, high caloric food.
A change in our governmental food policy that would stop favoring foods that are the basis of the WPD and instead favoring foods in the MeD would be a great step forward in terms of health and the environment.
Such a change in policy would likely help bring down some of the costs of the MeD due to economies of scale and other factors. But it is reasonable to expect that such a change in policy could result in food being more expensive than it is today.
What this study shows us though is our apparently cheap food is offset by high health care costs, lost years of life as well as lower quality of life, and a degraded environment.
Overall, the authors have presented an interesting conclusion that has me wanting to find more academic studies on the issues around the economics of a sustainable food policy and how we can move towards a more sustainable future.
Reference: Fresan, U., M. Martinez-Gonzalez, J. Sabate, and M. Bes-Ratrollo. 2019, “Global Sustainability (health, environment and monetary costs) of Three Dietary Patterns: Results from a Spanish Cohort (the SUN project).” BMJ Open, 9:e021541: 1–10.
By Ellen Clardy, PhD on .
Exported from Medium on December 15, 2022.
