Anorexia - lack of appetite causes fever sometimes.
Hi, body temperatures can keep varying, if maintained within the normal range you don't have to worry. There may not be a link between eating and temperatures. But certain infections like tuberculosis can cause an evening rise of temperature and increased sweating. This also causes a loss of appetite; as such this is accompanied by weight loss. So, record your temperatures, on a two hourly basis to detect an evening rise of temperature. Please check with your doctor to rule out this condition. Regards.