Human body stores energy as fat and glycogen. While glycogen can be stored in limited amounts, fat depots can vary dramatically from person to person. Usually, the minimum of fats the human body necessitates to function normally is 3% of the body mass for men and 12-17% for women. If the percent of body fat goes above the desirable range, the risk for developing heart diseases, high blood pressure, diabetes, osteoarthritis or cancers increases.
Types of Fats
Fats aresubstances composed of lipids or fatty acids and occurring in various forms or consistencies ranging from oil to tallow. They are usually soluble in organic solvents and insoluble in water. At room temperature fats may be present in either liquid-oils or solid form-fats, depending on their structure and composition.
Considering the effect of the fats in the body, these can be healthy (unsaturated fats) and unhealthy fats (saturated fats and trans fats).
Unsaturated fats are considered the ‘healthy’ fats and are encouraged as part of a rational diet. This type of fats helps fight the very diseases that consuming excess fat was said to cause: heart diseases and high cholesterol levels. Unsaturated fats are usually liquid at room temperature. They are found in most vegetable products and oils.
Unsaturated fats are divided into monounsaturated fats and polyunsaturated fats. Monounsaturated fats help lower LDL (low-density lipoprotein) – bad cholesterol, while also boosting HDL (high-density lipoprotein) – good cholesterol.
Polyunsaturated fats are also thought to help lower bad cholesterol. These are often a good source of omega-3 and omega-6 fatty acids, found mostly in cold-water fish, nuts, oils and seeds, and also in dark leafy greens, flaxseed oils and some vegetable oils. Essential fatty acid as omega-3 and omega-6 cannot be produced by the bodies, so eating these foods is the only way to get them. They lower blood pressure, combat bad cholesterol, fight inflammation and protect the brain and nervous system.
Saturated fats are those fatty acids that raise bad blood cholesterol levels, causing artery-clogging, heart diseases and strokes. Saturated fats have a chemical makeup in which the carbon atoms are saturated with hydrogen atoms. They come mostly from meats, whole dairy products and some tropical oils (coconut or palm kernel oil). These fats are solid at room temperature.
They are a source of vitamins and minerals, but it is recommended to limit them from the daily diet to a maximum of 7% of the total calories intake. Some researchers have shown that not all saturated fats are bad, some of them improving liver health and bone strength, promoting healthy lungs and healthy brain functioning, and supporting the body’s immune system.
Trans fat are produced when liquid oil is made into a solid fat in the process of hydrogenation. Trans fats act like saturated fats, but they are thought to be worse than saturated fats because they not only raise total and LDL (bad) cholesterol, but they also lower HDL (good) cholesterol. Sources of Trans fat include processed foods like snacks (crackers and chips) and baked goods (muffins, cookies and cakes), margarines, fried fast food items such as French fries etc.
Why do we need fats?
Although fats have received a bad reputation for causing weight gain, some fat is essential for survival. 20% – 35% of daily calories should come from a variety and balanced healthy fats, especially from polyunsaturated and monounsaturated fats. From the flavor of our food to the way our brain works, fats are important.
Fats arethe most efficient source of food energy. They provide nine calories per gram. Besides being a nutritious energy source, fat adds appealing taste, nice texture and attractive appearance to the food. Adding them to our diet, they give flavor to the food and elevate the mood, resulting less depression. More than this, we should know that vitamins A, D, E, and K are fat-soluble vitamins, meaning that the fat in foods helps the intestines absorb these vitamins into the body.
Fats are a must for healthy cells, because they are a vital component of the membrane that surrounds each cell of the body. Without a healthy cell membrane, the rest of the cell couldn’t function. Fat provides the structural components for the brain cell membranes, too, and is also an important part of myelin, the fatty insulating sheath that surrounds each nerve fiber, enabling it to fire electrical messages that make possible the performance of a multitude of tasks natural to a living body.
Fats are structural components of some of the most important substances in the body, including prostaglandins, hormone-like substances that regulate many of the body’s functions. Fats regulate the production of sex hormones.That’s one of the reasons why women need higher percentage of essential fat in their bodies (12-17%). Their essential fat includes some sex-specific fat found in the breasts, pelvis, hips and thighs, which is believed to be critical for normal reproductive function.
Lipids give shape to our body and insulate it to help regulate the temperature. Fats are also a protective cushion for internal organs, protecting them from injury and hold them in place. This cushion actually works as a shock absorber that protects vital organs when exposed to mechanical shocks.
In addition, fats give to the skin its rounded appeal and fight against the dry, flaky looks, so one might admit that the saying “fat and beautiful” is partially true.
The “Good” and the “Bad” Fats
A fatty food is basically a food containing a lot of fat. Fats can be found in everything that we eat, but certain foods contain more fats than others.
Fats contained in our diet are often blamed for being responsible for several health problems. In fact, a daily intake of fats is essential for the maintenance of good health. They are part of the structure of each of our cells, are a vehicle for vitamin A, D, E and K and produce energy (heat). The problem comes from a diet rich in foods containing “bad” fats and poor in foods containing “good” fats.
List of Foods That Are a Source of “Bad” Fats
- Oils that are not from first cold pressing and tropical oils (coconut).
- Fatty meats, such as fatty pork, fatty beef, etc.
- All oils, once heated, such as oils used in cooking.
- Fried foods, such as French fries, doughnuts and fried chicken.
- Hydrogenated margarine, hydrogenated peanut butter and shortening.
- Butter, cream, cheese and milk that are rich in fats.
- Cooked and roasted nuts.
List of Foods That Are a Source of “Good” Fats
- Almond oil, peanut oil, wheat germ oil, safflower oil, flax seed oil, soya oil, sesame oil, sunflower oil, etc., all made from the first cold pressing.
- Peanut butter, almond butter, sesame butter, non-hydrogenated and made of uncooked nuts or of nuts hardly cooked.
- Raw nuts, such as hazel nut, almond, cashews, pistachio, etc.
- Legumes, such as dried beans, string beans and peas.
- A fatty fruit: the avocado.
The more “bad” fats there are in the foods that we eat, the harder these foods are to digest, to be assimilated and to be used by the system. Many health problems, such as hypercholesterolemia, an excess of triglycerides, high blood pressure, the clogging up of the arteries and bad digestion, are related to a regular consumption of foods rich in “bad” fats.
General rule: Eat foods containing “good” fats daily and avoid those that are rich in “bad” fats. Learn how to read labels and ask questions, and you will know exactly what you are putting into your body.