Interestingly, we eat the same about of carbohydrate today that we did 100 years ago, and 100 years ago, heart disease and diabetes was rare. Evidence shows time and time again that it isn't carbohydrate that causes diabetes and heart disease, but rather individual sources of carbohydrate AND fat. The big difference in our diet is the source of our calories, and our total calorie intake.
Real honey has been replaced with fake, boiled honey.
Sugar has been replaced with HFCS and artificial sweetener.
Wheat flour has been replaced with dwarf wheat flour.
Butter and lard has been replaced by soybean and/or canola oil.
Soy is in everything, where it used to be in nothing.
Also, we consume around 400 total calories a day more, yet the majority of the jobs 100 years ago involved manual labor where today hardly any do. Ironically, since carbs have held constant, and protein is relatively unchanged, the thing that increased dramatically is fat intake. We ate lower fat diets 100 years ago. The difference is, steak, potatoes, butter and traditional wheat flour, brown sugar and molasses have been replaced by chicken breast deep fried in soybean oil, GMO dwarf wheat flour and white sugar/HFCS. Does anyone not eligible for AARP cook and bake with molasses or real honey anymore? They used to be (surprisingly nutritious) staples in households for ages.
IMO, vegetable oils are the biggest contributor of modern disease, with GMO soy and GMO wheat being #2 and #3. I don't see as big of an issue with actual ancient wheat as an agent of disease for occasional treats, but not as a dietary staple. I feel like eggs and bacon have been replaced by cereal and pancakes nowadays.