Well, here's some sobering news.
In study published in the Lancet, researchers tracked consumption of 15 dietary factors from 1990 to 2017 in 195 countries.
The study estimates that 1 in 5 deaths globally is associated with poor diet.
Researchers tracked 15 dietary factors such as diets low in fruits, veggies, legumes, whole grains, and diets high in sugary beverages, red meat, trans fats, and other things.
The authors do note that there were varying levels of data for each of the factors and across regions and countries, so the statistical accuracy is not airtight.
The trends are clear however, across the world, diets are not optimized and there are downstream health effects.
But What Is Optimal
Now, let's challenge some elements here. First, the researchers have an idea of what an optimal diet is, and they map that across regions of the world.
The problem with that however, is that generations of evolution and adaptation equip different people groups differently. That is to say, humans adapt to what is around them.
For instance, individuals with Asian ancestry produce more of an enzyme called amylase, which allows them to break down carbohydrates very efficiently. This is largely due to the presence of rice as a staple in the diet for thousands of years.
Next, the researchers seem to be taking the old food-pyramid approach to an optimal diet. This has been broken apart time and time again, so I won't do that here. But when they are tracking "whole grain" consumption, what is that to mean exactly? Are we talking about an heirloom millet? Or are we talking about GMO grains?
Broad definitions like this aren't helpful.
Junk Food Consumption
One thing that is true, the world as a whole is consuming more junk food than ever before. Sugary drinks and trans fats are being laundered into diets globally.
We evolved in a largely single-ingredient eating model. Getting back to that with as much variety as we can, is quite clearly the path forward.