I'm not sure about the role of preposition "at" here. Could you explain the meaning and show the similar examples?

Native speaker’s answer
Rebecca
"At" is a preposition that indicates the location or position of something. Here, "at" indicates that "the blame for rising obesity levels" is directed towards fat instead of sugar. Here are some similar examples using the preposition "at": Ex: She directed her words at me. Ex: He laughed at his friend.