There may be many reasons for diabetics to have no appetite, such as adverse reactions to medications such as metformin, diabetic ketoacidosis, nerve damage, diabetic nephropathy, and gastrointestinal disorders unrelated to diabetes. 1. Adverse reaction of metformin: the commonly used drug for diabetes is metformin, and the adverse reaction of metformin can be manifested as gastrointestinal symptoms, such as loss of appetite. 2. Diabetic ketoacidosis: poor control of diabetes leads to a significant rise in blood glucose in the body, which can cause the development of ketoacidosis, and the corresponding condition will affect the function of the nervous system, which directly results in decreased appetite. 3. Nerve damage: prolonged failure to control blood glucose can lead to nerve damage, damage to the stomach nerves can cause loss of appetite, and in severe cases, gastroparesis can also be caused. 4. Diabetic nephropathy: Diabetic nephropathy affects the metabolism of harmful substances in the body, leading to the accumulation of harmful substances in the body, which further stimulates the gastrointestinal tract and leads to loss of appetite. 5. Gastrointestinal disorders not related to diabetes: When patients develop gastrointestinal disorders, they can manifest as loss of appetite. Diabetic patients with no appetite need to seek medical observation in a timely manner, determine the specific cause through examination, and standardize treatment under the guidance of clinicians.