McDonald's breakfast map tells us a lot about Americans' health

McDonald's fans are loving the arrival of all-day breakfast, with McMuffins and other fast-food favorites now available day and night. But McD's popular biscuits will only be offered in a ribbon of southern states where biscuit sandwiches are gobbled with more frequency.

McDonald's helpfully released a map highlighting the biscuit zone. And it turns out heart disease, diabetes, and obesity are higher in the very same region where bacon, egg, and cheese biscuits -- which clock in at 450 calories and 26 grams of fat -- are preferred over the 300 calorie, 12 grams of fat McMuffin.

Maps: Biscuit zone vs. Heart disease hot-spots

The overlap in the maps shouldn't really come as a surprise. Southern states have some of the highest obesity rates in the nation. And studies have shown that the so-called "Southern diet," heavy in fried foods and saturated fats, increases the risk of heart disease, stroke, kidney damage and other health problems.