"You can manufacture all the glucose your body needs from a combination of protein and fat in the diet. In fact, the only macronutrient for which there is no actual dietary human requirement is carbohydrates. We never have to eat them at all! And if we want to be optimally healthy and live longer, cutting out the carbs (all the sugar and starch) can only improve your health and well being in the long run. Low insulin levels are the single biomarker that most consistently characterizes all the longest lived individuals."