Fat is a nutrient that is an important source of calories. One gram of fat supplies 9 calories - more than twice the amount we get from carbohydrates or protein. Fat also is needed to carry and store essential fat-soluble vitamins, like vitamins A and D. There are two basic types of fat. They are grouped by their chemical structure. Each type of fat is used differently in our bodies and has a different effect on our health.
When we eat a lot of high fat foods, we get a lot of calories. With too many calories, we may gain weight. Eating too much fat may also increase the risk of getting diseases like cancer, heart disease, high blood pressure or stroke. Health experts recommend that we should get no more than 30% of our calories from fat to reduce our risk of getting these diseases.
Fat is found in many foods. Some of the fat that we eat comes from the fat we add in cooking or spread on breads, vegetables or other foods. A lot of fat is hidden in foods that we eat as snacks, pastries or prepared meals.
We can reduce the amount of fat we eat by cutting down on the fat that we add in cooking or spread on foods. We can eat skim milk and low fat cheeses instead of whole milk and cheese. We can also use less fat, oil, butter, and margarine. Another way to cut down on fat is to drain and trim meats and take the skin off poultry. We can also read labels and compare the amount of fat in foods to make lower fat choices.
Fatty acids benefit the body in the following ways:
- Elevate mood, resulting in less depression
- Improve cognitive function in the elderly
- Improve learning and attention span in school-children
- Improve vision, especially night vision
- Lower the risk of cardiovascular disease
- Lowers the risk of breast and colon cancer
- Promote healthy skin
Types of Fats
Dietary fats are concentrated source of food energy. They are also the source of linoleum acid, an essential nutrient, and the fat-soluble vitamins A, D, E and K. While we all need some dietary fat each day, a tablespoon is generally sufficient when cutting back on fats, it is helpful to know which the most dietary culprits are.
Saturated fats are the only fatty acids that raise blood cholesterol levels. Saturated fats are found in meats and whole dairy products like milk, cheese, cream and ice cream. Some saturated fats are also found in plant foods like tropical oils (coconut or palm kernel oil). When margarine or vegetable shortening is made from corn oil, soybean oil or other vegetable oils, hydrogen atoms are added making some of the fat molecules "saturated". This also makes the fat solid at room temperature. Butter, margarine, and fats in meat and dairy products are all especially high in saturated fat.
We can reduce the saturated fats in our diets by using skim milk and low fat cheeses instead of whole milk and cheese. We can also use less fat, oil, butter, and margarine. At the table, use tub margarine instead of butter. Another way to cut down on fat is to drain and trim meats and take the skin off poultry. Simply reducing the total amount of fat we eat goes a long way toward reducing saturated fats.
Unsaturated fats are usually liquid at room temperature. They are found in most vegetable products and oils. An exception is a group of tropical oils like coconut or palm kernel oil which is highly saturated. Using foods containing "polyunsaturated" and "monounsaturated" fats does not increase our risk of heart disease. However, like all fats, unsaturated fats give us 9 calories for every gram. So eating too much of these types of fat may also make us gain weight.
We can reduce the fat and unsaturated fats in our diets by using less fat, oil, and margarine. We can also eat more low-fat foods like vegetables, fruits, breads, rice, pasta and cereals.
Cholesterol is an essential fat made by the liver. Many people get additional cholesterol by eating meat and dairy products. Too much dietary intake may raise blood cholesterol levels, and lead to heart disease. Cholesterol is transported through the bloodstream by lipoproteins.
Knowing the facts about cholesterol can reduce your risk for a heart attack or stroke. But understanding what cholesterol is and how it affects your health are only the beginning.
To keep your cholesterol under control:
- Schedule a screening
- Eat foods low in cholesterol and saturated fat
- Maintain a healthy weight
- Exercise regularly
- Follow your healthcare professional's advice
Trans fats are produced when liquid oil is made into a solid fat. This process is called hydrogenation. Trans fats act like saturated fats and can raise your cholesterol level. Trans fats are listed on the label, making it easier to identify these foods. Unless there is at least 0.5 grams or more of Trans fat in a food, the label can claim 0 grams. If you want to avoid as much Trans fat as possible, you must read the ingredient list on food labels. Look for words like hydrogenated oil or partially hydrogenated oil. Select foods that either does not contain hydrogenated oil or where liquid oil is listed first in the ingredient list.
Sources of Trans fat include:
- Processed foods like snacks (crackers and chips) and baked goods (muffins, cookies and cakes) with hydrogenated oil or partially hydrogenated oil
- Stick margarines
- Some fast food items such as French fries
Why do we need fats?
Although fats have received a bad reputation for causing weight gain but still some fat is essential for survival. According to the Dietary Reference Intakes published by the USDA 20% - 35% of calories should come from fat. We need this amount of fat for:
Body to use vitamins: 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.
Brains development: Fat provides the structural components not only of cell membranes in the brain, but also of myelin, the fatty insulating sheath that surrounds each nerve fiber, enabling it to carry messages faster.
Energy: Gram for gram fats is the most efficient source of food energy. Each gram of fat provides nine calories of energy for the body, compared with four calories per gram of carbohydrates and proteins.
Healthier skin: One of the more obvious signs of fatty acid deficiency is dry, flaky skin. In addition to giving skin its rounded appeal, the layer of fat just beneath the skin acts as the body's own insulation to help regulate body temperature.
Healthy cells: Fats are a vital part of the membrane that surrounds each cell of the body. Without a healthy cell membrane, the rest of the cell couldn't function.
Making hormones: 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, which explains why some teenage girls who are too lean experience delayed pubertal development and amenorrhea.
Pleasure: Besides being a nutritious energy source, fat adds to the appealing taste, texture and appearance of food. Fats carry flavor.
Protective cushion for our organs: Many of the vital organs, especially the kidneys, heart, and intestines are cushioned by fat that helps protect them from injury and hold them in place.