Fats, the richest source of dietary energy are organic compounds made up of carbon, hydrogen and oxygen. Each gram of fats provides 9 calorie. Fat is made up of different types of fatty acids, some of which are necessary for health in small amount. Fatty acids are usually classified as saturated fats, monounsaturated fats and polyunsaturated fats and trans fats depending on their chemical structure.
Healthy dietary fats
Research reveals eating foods rich in monounsaturated fatty acids improves blood cholesterol levels, which can decrease risk of heart disease. Foods rich in monounsaturated fats are olive, peanuts, avocados, nuts such as, almonds, hazelnuts and pecan, seeds such as pumpkin and sesame seeds.
This is a type of fat found mostly in plant based foods and oils. Studies show eating foods rich in polyunsaturated fatty acids improves blood cholesterol levels and can lower the risk of heart diseases. Foods high in polyunsaturated fats are sunflower, corn soybean and flaxseed oils, walnuts, flaxseeds.
Omega 3 fatty acids are important type of polyunsaturated fat. Eating fish 2 to 3 times a week is an excellent way to get omega -3 fats. Fish high in omega-3 fatty acids are salmon, tuna, trout, mackerel, sardines and herring. Our body cannot make omega 3 fatty acids therefore they must come from foods. Plant sources of omega -3 fats include flax seeds, walnuts, and soybean oil. The American Heart Association suggests 8 to 10 percent of daily calories should come from polyunsaturated fats. Evidence suggests eating more polyunsaturated fats can lower risk of heart diseases.
Harmful dietary fats
Saturated fats are the biggest dietary causes of bad cholesterol. These fats should be limited to 10 percent of calories. Consumption of greater amounts of theses fats is linked to an increased risk of heart disease and high blood cholesterol levels. Foods high in saturated fats includes meat products, butter ghee, cheese, cream, ice cream, chocolate confectionery, biscuits, cakes, pastries, coconut oil, a variety of fast food dishes.
Trans fats are saturated fats that have been processed and as a result, behave like saturated fats. These fats form when vegetable oil hardens (a process called hydrogenation). They raise bad cholesterol and lower good cholesterol which is a major risk factor of heart disease. Trans fatty acids are found in fried foods, commercial baked foods such as, cookies, crackers and margarines.
Functions of fats
Keep the body warm.
Protect internal organs.
Helps body absorb vitamins A, D, E, and K through bloodstream.
Produces hormones that help body to work properly.
Serves as the storage substances for the body’s extra calories.
Consumption of too much saturated fats is one of the major risk factors for heart disease. A diet rich in saturated fat causes a soft, waxy substance called cholesterol to build up in the arteries. In addition, a large intake of polyunsaturated fat may increase the risk for some types of cancer. However, reducing daily fat intake is not guarantee against developing cancer or heart diseases.
The 2015-2020 Dietary Guidelines for Americans offers the following recommendations about dietary fat intake:
Avoid trans fat: Check food labels and look for the amount of trans fats listed.
Limit saturated fats to less than 10 percent of calories a day.
Replace saturated fats with healthier monounsaturated and polyunsaturated fats.