The Masai of Kenya and Tanzania eat the same type of high animal-fat diet as North Americans, but they have a very low incidence of heart attacks. In spite of the large amount of saturated fats in their diets, they have lower body weights, waist measurements, blood pressures and cholesterol levels ( British Journal of Sports Medicine , July 2008). This is explained by the fact that the average Masai burns 4,000 kilocalories a day, which is roughly equal to walking 12 miles every day (this number includes the amount you burn for normal daily activities such as breathing and sleeping).
Saturated fat is the dominant fat in meat, chicken and whole milk dairy products. It raises cholesterol only when a person takes in more calories than he burns. A high-meat diet does not cause heart attacks in people who get a lot of exercise. Saturated fats are broken down by your body into two-carbon units. If you are getting too many calories, your liver converts these two-carbon units into cholesterol. If you are not getting enough calories, your body burns these units for energy.
When you take in more calories than your body needs, you store the excess as fat. Full fat cells release cytokines into your bloodstream, and they turn on your immunity. Your immunity is good because it protects you from infection, but if it stays overactive, it starts to destroy your body including your heart and blood vessels. The bottom line: if you eat much saturated fat, be sure to get plenty of exercise.