HIV, as well as many common treatments for the virus, can change your body's metabolism, which can result in conditions like an abnormal loss of fat tissue or insulin resistance. If you're living with HIV, a well-balanced diet can help you maintain a healthy weight, strengthen your immune system, boost your energy levels, and may even help your treatment regimen work better. Your doctor can help you devise an eating plan that ensures you're getting all of the nutrients you need, as well as drinking an adequate amount of fluids. If you're nauseated and cannot eat much, ask your doctor about medications that can help.