If you do not do something, but do something else instead, you do the second thing and not the first thing, as the result of a choice or a change of behaviour.
My husband asked why I couldn't just forget about dieting and eat normally instead.
丈夫问我为什么就不能忘掉节食而正常吃饭。
instead of
If you do one thing instead of another, you do the first thing and not the second thing, as the result of a choice or a change of behaviour.
They raised prices and cut production, instead of cutting costs.
他们提高了价格,减少了产量,而没有削减成本。