There's been so much press about protein lately that you'd think it was just invented. Our body-conscious society remains fixated by the stuff that can make Jennifer Aniston so skinny and yet bodybuilders so huge. To unravel the power of protein, the first installment of the Protein Primer will focus on the (fat) burning question: Do protein diets work? Diets like The Zone and Atkins are not only high-protein (heavy on the meat, chicken, fish, eggs and dairy products) but also low-carbohydrate, which means a very limited intake of foods including bread, pasta, fruits and vegetables like…