Dietary principles refer to a set of guidelines or beliefs that govern an individual's food choices and consumption patterns. These principles can be based on various factors such as cultural, religious, health-related, ethical, or personal preferences. For example, some people may follow a vegetarian diet due to their belief in the sanctity of life, while others may adhere to a low-carb diet for weight loss purposes. The key is that these principles help individuals make informed decisions about what they eat and ultimately impact their overall health and wellbeing.