She advised me to eat well balanced meals for better health.

well 在这里是副词，表示"很好地、充分地"，用来修饰形容词 balanced。 balanced 是动词 balance 的过去分词形式作形容词用，balance 意思是"平衡、均衡"，balanced 表示"平衡的、均衡的"。 well balanced meals 指各种营养成分比例适当、搭配合理的膳食，即"均衡的膳食"。