Here's a very interesting article from Scientific American about dietary guidelines and how they've changed over the years. Also, finally, an explanation I can understand about why people on Atkins' and similar diets lose weight, yet don't increase their cholesterol across the board.

By the early 1990s controlled feeding studies had shown that when a person replaces calories from saturated fat with an equal amount of calories from carbohydrates the levels of LDL and total cholesterol fall, but the level of HDL also falls. Because the ratio of LDL to HDL does not change, there is only a small reduction in the person's risk of heart disease. Moreover, the switch to carbohydrates boosts the blood levels of triglycerides, the component molecules of fat, probably because of effects on the body's endocrine system. High triglyceride levels are also associated with a high risk of heart disease.

I haven't read the whole article yet, but it makes sense. I'm on a high protein, low carbohydrate diet right now because everyone that I've talked to recently who has lost a large amount of weight has done it that way. But it never seemed healthy to me, and it didn't make sense that they weren't all dropping of heart attacks. But no one ever really explained it to me before.

Link from Byte Size Morsels