Hi, Thanks for writing in. If your friend is having symptoms of nausea and sweating which shows improvement on eating then conditions like low blood glucose and anxiety related stress are to be investigated in detail. What happens is there is a possibility of the blood sugar level going down to sub normal and then this causes decreased glucose metabolism in the brain and other organs. While slight low glucose in blood might be tolerated for a short time, longer durations of hypoglycemia can cause dizziness, weakness, nausea and sweating. It is important to eat well and take adequate amount of nutritious foods rich in vitamins and proteins. If his food intake is normal then he should get investigated for any malabsorption syndrome due to which there is less amount of glucose entering his system. He should also relax and stay stress free and have small meals at short intervals.