It’s important to follow a low-calorie, low-fat diet while taking this medication. If you eat a lot of fatty foods, even just one high-fat meal like a greasy burger, you’re more likely to have uncomfortable digestive side effects. Choose lean cuts of meat and low-fat dairy products. In general, no more than 30% of your calories at each meal should come from fat.
You’ll also need to take a daily multivitamin that contains vitamins A, D, E, K, and beta carotene while on this drug. The drug's fat-blocking properties also make it more difficult for your body to absorb fat-soluble vitamins. Do not take vitamins and Alli at the same time of the day.