Dietary fat is a type of fat found in various types of foods. They provide a storage form of energy, which is released as and when required by the body. Dietary fats help in normal functioning of the body, absorption of vitamins, and plays an important role in normal metabolic activities. The major types of dietary fats include saturated, monounsaturated, and polyunsaturated fats.
What are Saturated, Monounsaturated and Polyunsaturated Fats?
Technically speaking, from an entirely chemical standpoint, fats are triglycerides i.e. glycerol with 3 fatty acids, which are composed of long chains of carbon atoms. These carbon atoms are linked by either single bonds or double bonds. If there are one or more double bonds, the fat is said to be unsaturated. Fats containing a single double bond are called monounsaturated, while those containing many double bonds are called polyunsaturated. When all the double bonds are replaced with single bonds, the fat is said to be fully saturated.
Which Foods Contain the Various Types of Fats?
Saturated fats are generally solid at room temperature. Many types of food, especially those of animal origin are rich in saturated fats. The foods containing saturated fats can be dairy products, meat, and oils. Some of the major sources of saturated fats are highlighted below:
- Dairy products: Milk, butter, cream, ghee, and cheese.
- Meat: Beef (including beef fat or tallow), lamb, goat, pork (including pork fat or lard), and poultry (with skin).
- Oils: Palm and palm kernel oils, coconut oil, hydrogenated oils, partially hydrogenated oils, and stick margarine.
Oils that are rich in monounsaturated fats are generally liquid at room temperature. They become solid only after chilling. The plant-based liquid oils are the major sources of monounsaturated fats. These include the following:
- Olive oil.
- Safflower oil.
- Peanut oil.
- Canola oil.
- Sesame oil.
Some of the other sources of monounsaturated fats include various types of nuts and seeds, avocados, and peanut butter.
Polyunsaturated fats are a healthy form of fat along with monounsaturated fats. It is available from animal sources as well as from plant sources such as salmon, vegetable oils and certain types of nuts and seeds. The major sources of polyunsaturated fats include the following:
- Oils: Soybean oil, corn oil, flax oil, and safflower oil.
- Seeds: Sunflower seeds and flax seeds.
- Fish: Salmon, trout, mackerel, herring, and albacore tuna.
What are the Dietary Requirements of Fats?
Some amount of fats is required by your body for energy and for performing various metabolic functions. All fats contain 9 calories/g, which is twice that obtained from proteins or carbohydrates. About 20-30% of your daily energy needs should come from fats. Most of these fats should be monounsaturated or polyunsaturated fats. Saturated fat should ideally be avoided. But if you happen to consume them, they should be no more than 5-6% of your daily dietary intake. So, for an average daily diet of 2000 calories, only 120 calories should come from saturated fats. This translates to consumption of 13 g of saturated fats daily.
Which Fats are Good for Your Health?
As a general rule-of-thumb, you should go for the polyunsaturated fats and try to avoid the saturated fats. Polyunsaturated fats help to lower the levels of low-density lipoprotein (LDL) or “bad cholesterol” in your blood. Alternately, saturated fats tend to be rich in LDL, which can lead to atherosclerosis (deposition plaques of lipid in the coronary blood vessels), thereby increasing the risk of coronary artery disease (CAD) and stroke. Polyunsaturated fats also help to increase the levels high-density lipoprotein (HDL) or “good cholesterol” thereby protecting your heart from CAD and stroke.
Polyunsaturated fats also include the omega-3 and omega-6 fatty acids, which are called essential fatty acids because they cannot be synthesized by the body, and therefore must be supplied by the food you eat. These omega fatty acids are crucial for normal brain function and cell growth. The major functions of omega-3 fatty acids are highlighted below:
- Reduces risk of heart diseases by lowering the levels of triglycerides (a type of fat) in the blood.
- Prevents atherosclerosis.
- Reduces irregular heart-beats.
- Lowers blood pressure.
The major functions of omega-6 fatty acids are highlighted below:
- Prevents the risk of developing diabetes.
- Helps to lower the levels of blood sugar.
- Helps to lower the blood pressure.
What Should You Look for on the Nutrition Label?
Whenever you buy pre-packaged food, look at the nutritional labelling on the package. This contains all the nutritional details, including those of fats. This will help you to get a rough idea of how much fats are going into your diet. Check for the following on the package label:
- Check for the total fat content, as well as the amounts of saturated and trans fats. The remaining will be the healthy variety i.e. monounsaturated and polyunsaturated fats.
- Some packages may contain information on the amount of monounsaturated and polyunsaturated fat content. This will help to plan your diet.
- Check for the amount of fat per serving. You should remember to add-up the number of servings in a meal to get an idea of the fat consumed.
What Does the FSSAI Say?
The Food Safety and Standards Authority of India (FSSAI), the apex food regulatory body in the country, advises to go for a natural way to fight heart disease in the Indian population. The FSSAI health advisory highlights the following:
- Avoid consuming industrial vegetable oils.
- Go for lots of leafy green vegetables.
- Consume less sugar.
- Consume nutrient dense foods.
- Go for fermented food products.
The FSSAI also advises to maintain a healthy body weight and to get regular health check-ups.
From the foregoing discussion, it is clearly evident that many of the fats consumed in our daily diet are very important for the normal functioning and energy metabolism of our body. However, we should exercise caution and make an informed choice about which fats to consume and which to avoid. The polyunsaturated fats, along with the monounsaturated fats are the healthy choice, while we should avoid saturated fats as much as possible to keep heart disease away and lead a healthy and productive life.
- Medline Plus: Facts about Polyunsaturated Fats. US National Library of Medicine (NLM), National Institutes of Health (NIH), USA. Available at: https://medlineplus.gov/ency/patientinstructions/000747.htm. Accessed on March 2, 2017.
- FSSAI: Safe and Nutritious Food @ Home – Cardiovascular Diseases. Available at: http://fssai.gov.in/SNFAtHome/HTML/cardio.jsp. Accessed on March 2, 2017.