Is the following sentence incorrect?
If it sounds familiar, it's time to make some subtle changes to your daily life to make it easy to lose some extra weight and keep it off for good.
I think it is correct, but my answer key says it should be easier instead of easy.
The sentence as you have written is grammatically correct. There is no issue with the tenses, etc.
It's a question of nuance. As the sentence describes the process of dieting, there is implied knowledge that it is not 'easy' to lose weight. Therefore, the subtle changes mentioned would make the process easier, but not an easy process that completes quickly.
