Trans Fats and Saturated Fats
There are also very unhealthy fats - saturated fats and trans fatty acids. These fats are extremely difficult to break up in the process of digestion. Consequently, they tend to clump together and form droplets of fat that accumulate as a part of plaque in our arteries. Saturated fats are found in meat and dairy products, including the cheese that we are eating in astronomical amounts these days; and trans fatty acids are found in highly processed hydrogenated oils - those inexpensive vegetable oils" that we pour on our once-healthy salads and in which we deep-fry our potatoes and other foods.
Fats, in the fireplace analogy, burn like coal, the hardest and slowest-burning fossil fuel. They contain twice as much energy per gram as the other fuels - proteins and carbohydrates. With significant physical exercise, which requires a large turnover of energy, our bodies can use fats to great advantage. Without activity, however, we would do well to remember the old adage "A moment on the lips and forever on the hips," and limit our intake of foods that are high in saturated fat.