Lipitor is a prescription drug that contains atorvastatin, which is used to lower cholesterol levels in the blood. According to the sources provided, there is no evidence to suggest that Lipitor is less effective when taken with low-fat meals.

Lipitor works by blocking an enzyme in the liver that is responsible for producing cholesterol. It is recommended to take Lipitor with or without food, but it is important to maintain a consistent diet while taking the medication [2]. However, the sources do not mention any specific impact of low-fat meals on the effectiveness of Lipitor.

It is important to note that Lipitor may interact with certain foods, such as grapefruit and grapefruit juice, which can increase the risk of side effects. Therefore, it is recommended to avoid consuming grapefruit products while taking Lipitor [2].

In conclusion, based on the sources provided, there is no evidence to suggest that Lipitor is less effective when taken with low-fat meals. However, it is important to maintain a consistent diet while taking the medication and to avoid consuming grapefruit products to reduce the risk of side effects.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.webmd.com/drugs/2/drug-3330/lipitor-oral/details
[3] https://www.medicalnewstoday.com/articles/248136