In this study, moderately obese subjects consumed one of two different low-carb diets as part of a weight loss program. In the first diet, most of the protein was from red meat and was higher in saturated fat. In the second diet, most of the protein was from poultry, fish and shellfish and was higher in polyunsaturated fat. The researchers figured both groups would lose weight (they did) but wanted to see what differences might occur in blood measures like cholesterol.
Interestingly, despite "high cholesterol and fat" intakes on both diets, neither diet produced significant changes in cholesterol levels. And triglycerides came down in both groups (though the effect reached statistical significance only in the poultry-fish-shellfish group).
Saturated fat from whole foods (like eggs) is nothing to fear, especially when the overall content of the diet is also rich in other fats like the omega-3s and the monounsaturates. And an increasing body of evidence is showing that replacing high-sugar processed carbohydrates with fat has significant health benefits.
Remember, though, that all saturated fat is not created equal. Healthy saturated fat from natural sources like coconut, eggs and hormone-free beef is very different from the damaged fats from charred meats or fried foods, not to mention from deadly trans-fats. The principles of the Atkins Advantage center on whole foods and wholesome snacks. Keep your sugar intake as low as possible, control your carbohydrate consumption, keep your trans-fat intake at zero, get adequate protein, fiber, antioxidants and omegas, and you needn't worry too much about a little naturally occurring saturated fat.
That's the lesson to be learned from a growing body of rigorous research, and one we should heed well if we want a healthy life.
Effects of low carbohydrate diets high in red meats or poultry, fish and shellfish on plasma lipids and weight loss. Bridget A Cassady, Nicole L Charboneau, Emily E Brys, Kristin A Crouse, Donald C Beitz and Ted Wilson.
Nutrition & Metabolism 2007, 4:23doi:10.1186/1743-7075-4-23