Techniques for managing diabetes and pre-diabetes using light are disclosed herein. In one example, a light generating device is positioned to a body part of a diabetic or pre-diabetic patient, and a beam of light generated by the light generating device is directed to the body part of the patient to control blood sugar level of the patient. In various embodiments, the beam of light directed to the patient can also help to control the blood lipid level such as triglyceride level, blood liver enzyme of the patient, and various other symptoms of diabetes and pre-diabetes. In various embodiments, the body part includes body area rich in adipose tissue, such as the abdominal area, thigh, buttocks, and upper arms of the patient.
