Loss of appetite can occur due to stress, illness, infections, digestive issues, medication side effects, or nutritional deficiencies. It is essential to identify the underlying cause, as persistent loss of appetite can lead to weight loss or nutrient deficiencies. You should consult a doctor for a proper evaluation, which may include a physical examination, blood tests, and review of your medications and medical history. Based on the findings, your doctor can recommend appropriate dietary adjustments, treatment, or further investigations. Do not try supplements or medicines on your own without professional guidance.