Hidebound outside removing economic cause, dietary habit, cooking method, sometimes partiality for a particular kind of food, long-term verticalWine, long-term and maigre, also be main reason.

• 营养不良除经济原因外，饮食习惯，烹饪方法，有时偏食，长期纵酒，长期素食，亦为重要原因。