High blood pressure is the condition that should be controlled for a dilated aorta as well as avoid any heavy lifting or strenuous activity when the enlarged aorta is greater than 4.0... it is usually referred to as an aneurysm. Left ventricle can/will enlarge with higher than normal blood pressure.
Additional weight loss will put less stress to the heart and obviously that would be helpful for healthful heart, and not smoking helps the vessels to remain healthy.