If you read the link pfpelican posted, it seems that the FDA recommendation to eat 300 gm (1200 calories) of carbs per day may be part of the problem. For years the medical profession has been telling us to watch our fat intake. Perhaps it's the carb intake that we should be watching. I believe that there is mounting evidence that reducing carbs also leads to lower lipid levels, as well as weight reduction.
With regard to the increase in type II diabetes diagnoses, I suspect a good portion of that has come from lowering the fasting blood glucose level by which one is classified as having diabetes. About 10 years ago it was reduced to 126 mg/dl. I think prior to that it was 140 or higher. Additionally, there is the classification of pre-diabetes for those with fasting blood glucose levels between 100-126. I would suspect that this has triggered more folks to have a more definitive test for diabetes such as an oral glucose test, resulting in more diagnoses of the disease. In other words, I am saying that perhaps many more folks had diabetes years ago, but were not diagnosed as such because their fasting blood glucose was not above the then higher diabetic threshold. Today those folks would be considered diabetic. And who knows how many of the folks that died from heart disease in the past were really diabetic by today's standards, but were considered non-diabetic back then.