Common signs of an unhealthy diet include low energy levels, weight fluctuations, and various health issues such as digestive problems or nutrient deficiencies. Individuals may also experience frequent cravings for unhealthy foods or have difficulty concentrating. Physical signs may manifest as skin problems or hair loss. Ultimately, these indicators suggest inadequate intake of essential nutrients and can lead to long-term health complications. Recognizing these signs is crucial for making necessary dietary adjustments and improving overall health.