Does alli diet work a high fat meal may delay the time of the effect of this drug. Many people using this medicine do not have serious side effects. Do not take this medication without doctor advice if you have chronic malabsorption syndrome or gallbladder problems. Do not use Orlistat if your medical history includes kidney stones, have anorexia or bulimia, have diabetes, take cyclosporine, or take any other weight-loss medicine. Weight loss begins within two weeks and continues for years. The effect of using Orlistat for more than 2 years is still unknown. If you have diabetes, weight-loss is likely to reduce your blood sugar levels. Consult to your doctor about the dosage of Orlistat if you’re taking oral diabetes medication or insulin. Orlistat should not be used during pregnancy, becoming pregnancy or lactating. Do not use before breast-feeding without doctor’s permission.