Dietary rules refer to guidelines or restrictions that govern what a person can and cannot eat based on their cultural, religious, health-related or personal preferences. These rules may vary from one individual to another depending on factors such as beliefs, allergies, intolerances, medical conditions, or lifestyle choices. Examples of dietary rules include vegetarianism, veganism, kosher and halal food restrictions, gluten-free diets, low-carb diets, among others. People who follow these rules usually have to pay attention to what they eat in order to maintain their health or adhere to their beliefs.