The US diet has changed dramatically in the last 200 years. Many of these changes stem from a single factor: the industrialization and commercialization of the American food system. We've outsourced most of our food preparation, placing it into the hands of professionals whose interests aren't always well aligned with ours.
It's hard to appreciate just how much things have changed, because none of us were alive 200 years ago. To help illustrate some of these changes, I've been collecting statistics on US diet trends. Since sugar is the most refined food we eat in quantity, and it's a good marker of processed food consumption, naturally I wanted to get my hands on sugar intake statistics-- but solid numbers going back to the early 19th century are hard to come by! Of all the diet-related books I've read, I've never seen a graph of year-by-year sugar intake going back more than 100 years.
A gentleman by the name of Jeremy Landen and I eventually tracked down some outstanding statistics from old US Department of Commerce reports and the USDA: continuous yearly sweetener sales from 1822 to 2005, which have appeared in two of my talks but I have never seen graphed anywhere else*. These numbers represent added sweeteners such as cane sugar, high-fructose corn syrup and maple syrup, but not naturally occurring sugars in fruit and vegetables. Behold: