Muesli is often considered a healthy breakfast option, but its health depends on how it's made. Originally made from oats, nuts, fruit and wheat, muesli provides fiber, whole grains, antioxidants and healthy fats. However, many store-bought varieties are high in sugar, calories, carbs and fat. For muesli to be healthy, it should be unroasted, have a small serving size, limited carbs and saturated fat, and a low glycemic index. Making muesli at home allows controlling ingredients to avoid dried fruit and roasting for optimal nutrition.