It is believed that bringing vegetable or mustard oil home on Saturdays is a sign of illness. According to a number of Hindu scriptures, purchasing oil on Saturdays has a negative impact on your health and increases your risk of contracting dangerous diseases. So in order to avoid any kind of bad luck, stay away from burgers or sauces made of oil. You are free to eat everything you want from Monday to Friday, but on Saturdays, avoid eating these two for your own safety!
However, if you want to bring good fortune into your home during the Shani Sadesatti, donate food made with mustard or oil.