Paulus, about the only time that happens is in the first few months when the body starts burning its stored fat for the first time. It churns up an enormous amount of fat into the system and stays there until the body starts burning it all off. Cholesterol readings can be high intially. After 6 weeks to 3 months when the fat is burned off, they plummet though. Studies show that this diet reduces cholesterol much better than a low fat diet and also increases HDL, which is something a low fat cannot do. Low fat also results in HIGH triglycerides, one of the worst signs for coronary heart disease.
Atkins recommends getting your cholesterol checked BEFORE and at 6 months. 9 times out of 10 the cholesterol is way down, HDL is up, and triglycerides are up. Mine went from 318 to 221 and my triglycerides went from 495 to 66. My risk of heart disease has fallen dramatically and my doctor is thrilled with results.