Good luck with your quest. I think a false choice has been created for you e.g. low bgs by eating less carbs versus a healthy heart by eating less fat!
What if, as many here believe , the root cause of diabetes and elevated LDL (aka the 'bad' kind) or low HDL (aka the good stuff) is the same thing - insulin resistance. Many people fix their insuln resistance with a low carb and high fat diet, enjoy their food without hunger and fix these metabolic problems. Good Luck!
I recently found a study on an island population where there are a lot more people over 100 years old than might be expected. Japan possibly?
A government study found that the oldest people had more meat and dairy in their diet and cholesterol levels higher than average.