In the past century or so, the Western diet has changed drastically.
In the talk above, Dr. Stephan Guyenet, an obesity researcher who is also one of my favorite bloggers, talks about how the American diet has changed from simple, home-cooked meals to highly refined fast foods.
Today, what we call “food” is often little more than a bunch of highly refined ingredients mixed together with a range of artificial chemicals designed to taste so good that we can’t stop eating.
Major Changes in The Types of Foods Consumed
In the past century or so, there has been a dramatic shift from simple, local, home-cooked foods to commercially prepared foods.
This graph shows the changes in macronutrient consumption from 1909 to 2009, according to the USDA Economic Research Service.
We see that carbohydrates have remained relatively stable. They declined at the middle of the century and begun to rise again around 1980.
Fat consumption has increased gradually, mainly from processed vegetable oils. Fat as a portion of total calories went from 31% to 41%.
Protein has remained relatively stable.
Sugar and Vegetable Oils
There are two ingredients that I personally think are of particular importance, sugar and vegetable oils.
We can see that the consumption of sugar has jumped from less than 10 lbs/year to about a 100 lbs/year, in the past few decades the increase being driven by high fructose corn syrup.
The types of fats that were consumed also changed. At the turn of the 20th century, lard and butter were the prevalent added fats in the diet.
The population almost eliminated lard and butter and replaced them with margarine and processed seed/vegetable oils. Consumption of vegetable oils increased 3-fold.
Since the year 1970, average calorie intake has increased by 425 kcal/day, with a sharp increase around the year 1980, which coincides with the beginning of the obesity epidemic.
Sources vary on this (it depends on which data you are looking at) but everyone agrees that there has been a major increase in calorie intake, primarily driven by increased consumption of processed foods.
Take Home Message
It is clear is that there hasn’t been any massive shift in the type of macronutrients that are eaten. However, the quality of foods have deteriorated significantly.
People are eating more sugar, more vegetable oils and they are getting them from highly processed, highly palatable foods that drive increased calorie consumption.
As people shifted from real, home-cooked foods to processed, hyperpalatable foods, they became sicker and fatter. Period.
Unfortunately, this development shows no sign of slowing down yet, but I think that as more and more people become aware of the importance of eating real food, things will change for the better.