Lipitor is a medication used to lower cholesterol levels in the body. The active ingredient in Lipitor is atorvastatin, which works by inhibiting an enzyme involved in cholesterol synthesis [1]. According to a study published in the Journal of Lipid Research, a high-fat diet can lead to an increase in cholesterol levels in the body [2]. However, the same study also found that atorvastatin was effective in reducing cholesterol levels even in the presence of a high-fat diet [2]. Another study published in Lipids in Health and Disease also found that atorvastatin was effective in reducing cholesterol levels in individuals with high cholesterol levels who consumed a high-fat diet [3]. Therefore, based on these studies, it can be concluded that Lipitor can still be effective in reducing cholesterol levels in individuals with a high-fat diet. However, it is important to note that a high-fat diet can still have negative effects on overall health and it is recommended to maintain a balanced diet and exercise regularly to promote overall health [2][3].

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5766553/
[3] https://lipidworld.biomedcentral.com/articles/10.1186/1476-511X-10-23