I solved it. I was treating all adverbs as adjectives in the diagram. When the sentence has an adverb you skip to the next vertical to the direct object then you read the adverb.
"In a sentence, an adverb that modifies a verb may appear either before or after the verb."
Sentence 1 is the preferred sentence: You can achieve a healthier lifestyle by eating vegetables.
And then there is another way of reading it: by eating vegetables You can achieve a healthier lifestyle by eating vegetables