The standard American diet, also known as SAD, has been linked to nutrient deficiency, chronic disease, and obesity. SAD is characterized by high amounts of refined carbohydrates and refined sugar, and not enough fruits and vegetables. The Greatist points to several studies that show why upping the intake of some nutrients could benefit many Americans. They point to these important nutrients as being critical to increasing our overall nutrional health: potassium, fiber, calcium, vitamin D, and iron. Increasing these nutrients may reduce the risk of high blood pressure (potassium), diabetes (fiber), osteoporosis (calcium), heart disease (vitamin D), and fatigue (iron).