What Is Fat?
Fat is an essential component of a healthy diet. Our brains are made up of 70 percent fat, and a layer of fat surrounds the heart and acts as an emergency source of energy. Fat is a component of all of our cells. We need it to absorb fat-soluble nutrients. It helps regulate our body temperature. Fat is used in cell growth and in the maintenance of our nervous system. And essential fatty acids (EFAs) are found only in some foods; these compounds are used to regulate metabolism and our immune systems. We need fat to live.
There are three main types of molecules in food: carbohydrates, protein, and fat (alcohol is another, but it doesn't factor into this discussion). Carbohydrates provide 4 calories per gram, protein also provides 4 calories per gram, and fat provides 9 calories per gram of food. That difference alone is what makes restricting fat in our diets important.
Do not feed children under the age of two a low-fat diet! They need to consume a good amount of fat to help their brains develop and to help sustain their bodies' growth rate. The American Academy of Pediatrics states that fat intake should not be limited until a child is at least two years old.
Good Fat, Bad Fat
There is only one true bad fat: trans fat. This artificial substance is created by pumping hydrogen gas through oil, resulting in a tasteless, extremely stable fat that is very valuable to the food processing industry — and very bad for your body. Hydrogenated fats are the only fat you really have to avoid, no matter what.
Even Cooking Light, one of the oldest low-fat recipe magazines, is including butter and olive oil in many of its recipes. This reflects the newer research and opinions that these natural fats are not bad for you as long as they are eaten in moderation. In fact, some of their recipes have 39 percent or more calories from fat!
Don't look at fat as the enemy. Rather, think of fat as a necessary substance you have to consume, and include fats that are actually good for you in your diet. Naturally occurring fats, including vegetable oils, monounsaturated oils, and oils found in nuts, fish, and avocados, are delicious and healthy. One of the healthiest diets on earth, the Mediterranean diet, is fairly heavy in monounsaturated fats like olive oil.
Saturation
There are two basic types of fat: saturated and unsaturated. There is a controversy in the medical and scientific communities about whether saturated fats are bad for your health.
The term saturated refers to the presence or absence of double bonds between carbon molecules in a fat. Saturated fat is simply a chain of triglycerides, or fat molecules, which has all of its carbon molecules bound to hydrogen molecules, with no double bonds between the carbon molecules. Saturated fats are usually solid at room temperature.
One of the newer terms to pop up in the saturated versus unsaturated fat debate is AGE. This stands for advanced glycation end products, which are toxins formed when fat and proteins are subjected to high heat. These substances may actually be the cause of the harmful effects blamed on saturated fats, including the lipid hypothesis, which is the basis of current medical advice regarding fat.
Unsaturated fats are divided into two groups: monounsaturated and polyunsaturated. These molecules have one (monounsaturated) or more (polyunsaturated) double bonds between the carbon molecules because they are missing two or more hydrogen molecules. These fats are usually liquid at room temperature.
Some studies have shown that a diet containing moderate amounts of saturated fat can help protect your health. Butter contains vitamins and minerals, and some of the medium-chain saturated fats like coconut and palm oil have antimicrobial and antiviral properties and can help prevent oxidation of cholesterol.
