Hey, Thanakar, I didn't find ANY studies on Pubmed about "saturated fats you suffer from a temporary constriction of the arteries." The saturated fat studies I did find had a lot of misinformation in them about cholesterol and risk factors, and they were older.
What I know about saturated fats are that SOME people are sensitive to them, and it does raise certain cholesterol levels. Most people go ahead and get great blood numbers as long as they stay away from transfats, which do have great potential for harm.
I've only read about South Beach online and flipping through the book at a bookstore, I wasn't impressed with his research or his idea of a diet. He seems stuck between the old thinking about fats and the new thinking about carbs.
The new studies show that stroke risk comes from cholesterol too low, and insulin too high. Saturated fat is slowly being rehabilitated. A good source for questions about fats is "Know Your Fats" by Mary Enig. Here's what she has to say on the subject:

"The physiology of fats and cholesterol is fully covered in Chapter 2. Almost half of this chapter is devoted to shattering popular myths about saturated fats. Not mincing any words, Enig methodically demonstrates the faulty data and reasoning behind the ideas that saturates either cause or contribute to heart disease, diabetes, colon cancer, mental illness, obesity and cerebrovascular disease. For example, after trashing the “data” that supposedly prove that beef and beef fat caused colon cancer, Enig flatly concludes: “And now, more than three (3) decades after the initial fraudulent report, the anti-animal fat hypothesis continues to lead the nutrition agenda. It was a false issue then, and it remains a false issue today.”

Subsequent chapters deal with fats and oils historically used in Western diets; the fatty acid composition of various oils and fats such as coconut, butter, lard, and olive oil; and a succinct summary of “fat facts.” The book is rounded out by detailed appendices on definitions, fatty acids in a huge number of foods and molecular compositions of major fatty acids.

Most interesting is Enig’s insider take on the nutritional research world and the forces that work behind the scenes to manipulate the facts. Never one to shy away from controversy, Enig blasts such organizations as the American Dietetics Association, the Center for Science in the Public Interest, the American Heart Association, and the food industry in general. She accuses research scientists who denigrate foods containing saturated fats as “flat-earthers.”

Check her out on the web, she's a fascinating and outspoken scientist.

http://www.westonaprice.org/book_reviews/know_your.html