"Every day you consume food to nourish and fuel your body, as eating many different nutrients that are essential to maintaining optimal health. These are called essential nutrients and include vitamins, minerals, proteins, fats and carbohydrates. However, some nutrients are made in the human body, and these are called non-essential nutrients. Although termed non-essential, they are still required by the body for supporting daily bodily processes. Some non-essential nutrients are also found in the diet, although many are also made by the body."
See some of the nutrients you need @ FitDay (not for weight loss, but things EVERYONE needs)