From Carbs to Fat to Diabetes

The food pyramid has recently been rearranged to promote more whole grains, fruits, vegetables and legumes, and fewer simple carbohydrates (so-called bad). The major emphasis is to stay away from those simple carbohydrates with a high glycemic index (foods made from refined flour and sugar, and which the body readily converts to simple sugars). Simple carbohydrates have been shown to produce a sharp elevation in blood-glucose levels, which promotes disease. Why the sudden change away from these carbs?