>Don’t eat anything your great-great-grandmother wouldn’t recognize as food. (Sorry, but at this point Moms are as confused as the rest of us, which is why we have to go back a couple of generations, to a time before the advent of modern food products.)

Generation length varies significantly across human history, geographical location, population groups etc. but the average across the last quarter million years is twenty seven years [5].

The average American is 39 (Pollan was 52 when he wrote this) so let's say roughly speaking we're looking at 39+(4*27) =147 so 2007-147=1860. In the 1860s life expectancy at birth was about 36 and life expectancy at age 15 was about 60. So we're talking roughly the mid-late 1800s to early 1900s. In other words, before the modern use (and quantity) of vegetable oils, food processed on a large scale, most preservatives, modern food advertising, packaging, foods designed for texture, et cetera. These things only started in the early 1900s, but it took time for production to increase, around WW2 - and by the 1960s the average Eastern European was consuming about 6kg of mass-produced vegetable oil a year. Not enough to make everyone obese, but enough to show up as a blip on a chart. Does it? Yes. The heaviest segments of society were already increasing in weight at this time [0].

In the 1960s, texture science and research on the appearance of food started to take off [3] - and yes, even in the USSR this was something people paid attention to. Packaging was now intentionally designed to stimulate appetites. Stabilizers, colorants and flavorings were in use, even in many poorer countries. By the 1970s, soda was in full swing. There were local sodas (Baikal in the USSR, Kofola in Czechoslovakia) but even Pepsi entered the Soviet market in 1971, and it was immediately popular, despite its high price. Now you can see obesity becoming a problem societally; in 1975 it was considered an issue and measured nearly worldwide for the first time [4].

Defending my claim that "obesity rates back then were near zero" is a bit tricky because it was so rare it wasn't considered a societal problem in the early 1900s. But we do have some data points. For example, the heaviest 1% of 18-26yo men in Denmark had a BMI of 28 in 1939 [0], and this did not cross 30 (obese) until 1951. The heaviest 5% of 18-26yo men had a BMI of under 25 in 1939; today, the Danish national average is 25.3.

As for heart issues, in 1900 there were 137.4 deaths of heart disease per 100k, vs 192.9 deaths per 100k in 2010. That is despite the fact that 92 million US adults are on statins, which often have serious side effects.

Personal anecdotes unfortunately don't hold up to the data, which is crystal clear: in the year 1900, when we ate a pre-modern diet, rates of obesity were near-zero and deaths from heart disease were significantly fewer.

But, like you said, what if someone ate that farmers' diet today? Turns out the Amish have significantly lower rates of obesity than their neighbors. Must be the physical exercise, not the diet, no? Well... the US military is quite physically active compared to your average person, and yet 70% are overweight or obese.

[0] https://www.science.org/doi/10.1126/sciadv.adg6237

[1] see e.x. Romania, Yugoslavia https://ourworldindata.org/grapher/vegetable-oil-production?...

[2] https://www.nejm.org/doi/full/10.1056/NEJMp1113569

[3] https://doi.org/10.1080/20549547.2017.1355720

[4] https://ourworldindata.org/obesity

[5] https://doi.org/10.1126/sciadv.abm7047

As a side observation and not particularly referring to your reply, I see that people tend to put food or nutrition if you want, almost in the same scope of politics and religion, many people I know who I consider very open-minded will get very on the defensive whenever I tell them that the best thing to do is to reduce the intake of proteins of animal origin and increase plant consumption. That goes to show that years of propaganda have worked very well.

    Just because you cannot see a clearly defined boundary does not mean it is not there.  A corn cob is food, a processed piece of corn mixed with <insert flavoursome/colourful/preserving chemical> sealed in a plastic bag with a six month shelf life is not