The body requires protein to maintain the muscles and to produce hormones. Essential fatty acids are needed for cell replication and to maintain the structure of the nervous system. Therefore, any reduction of Calories must be accomplished by reducing saturated fats and carbohydrates. A diet should never reduce the amount of protein or essential fatty acids (EFAs). The body needs at least 15 grams of EFAs per day, which can be obtained by eating meats, fish, nuts, and flaxseed. Very low calorie diets (less than 1300 calores per day) should be avoided because they generally do not provide all the nutrients needed for good health.