There's no such thing as an essential carb. You would die without protein, fat and fibre. The amount of carbs that you ought to consume on a daily basis need to be custom tailored to your own life yet to you. Grains are not nutrient dense they're primarily a starch which get broken down almost as soon as they pass your lips. Or so if you're with a huge color budget, can have some sugar? Ye, of course.