Hi, My Husband Has Elevated ALT Levels. His GP Has

Hi, my husband has elevated ALT levels. His GP has been monitoring this the last 6 months and his levels haven't moved, so an ultrasound of his liver was done a few days ago and fat was found. He has been referred to a gastroenterologist and his appointment is in July. Is there anything I can do to see if we can lower those levels the next few months as far as his diet goes?