The word fat seems as frightening as it is fattening! Do we need to shun fat completely from our diets? Are all fats the same? Let’s decide!

Fat is indispensable to life. We need it for….

• Energy. The most concentrated source of calories, fats provide 9kcal/g.
• A reserve supply of energy in the form of adipose tissue.
• Carrying fat-soluble vitamins like A, D, E and K and antioxidants.
• A protective layer around essential organs.
• Hormone synthesis.
• Our cell membranes. Fat plays a very important role in brain and eye health.
• Elasticity and to prevent ageing of skin.
• Insulation against temperature changes by means of subcutaneous fat stores.
• Lubrication and to reduce wear and tear of joints.

FAT TYPES

Triglycerides: Dietary fat consists primarily of triglycerides. Triglycerides are three fatty acids joined to a glycerol backbone. Fatty acids are made up of carbon chains containing up to 22 carbon molecules in the chain. The carbon atoms in the chain are linked by single and double bonds. Hydrogen atoms are attached to the carbon chain. The number of hydrogen atoms determines the degree of saturation of the fatty acids. The properties of fatty acid such as melting point and smoking point depend on their chain length and the number of double bonds.

Saturated fat (SFA): These fats are solid at room temperature. They have relatively high melting temperature as the carbon atoms are linked by single bonds and are saturated with hydrogen atoms (hence the name). They are obtained from the storage fats of animals and products derived from them. They increase the risk of cardiovascular disease by elevating levels of LDL (bad) cholesterol as well as total cholesterol.

Sources of saturated fat are butter, ghee, whole milk, cheese, meat fat, coconut oil and palm oil. You can reduce the amount of these fats in your diet by trimming visible fats, discarding poultry skin, draining fat from cooked meat, reducing the amount of butter, cheese and cream if intake is high. Use ghee only occasionally for cooking.

Monounsaturated fat (MUFA): MUFAs are good fats. They are liquid at room temperature and contain one double bond. This makes the melting point low, hence they do not solidify and stick to artery walls. They are regarded as the most beneficial type of fatty acid as they do not have a cholesterol-elevating effect. Moreover, when it is substituted for SFA, it lowers LDL cholesterol without adversely affecting HDL or good cholesterol concentrations.

You can get MUFAs from oils like olive, soya and mustard; nuts — walnuts, pistachios and almonds; seeds — sunflower, flax seeds, olives. And dark chocolate!

Polyunsaturated fat (PUFA): These fats are also liquid at room temperature and have lower melting points than MUFAs as they contain two or more double bonds. They are prone to rancidity as they are easily oxidised in foods. They cannot be synthesised in the body and are obtained primarily from the diet. They play vital roles in immune response, blood clotting and inflammation and are also involved in cholesterol metabolism. PUFAs are divided into two types:

Omega 6: This type of PUFA has a parent fatty acid called linoleic acid. It is found in plant oils from corn, sunflower, soybean and safflower. A derivative of linoleic acid called GLA (gamma linolenic acid) taken as a supplement for three to four months may help relieve symptoms of pre-menstrual syndrome (PMS) in some. It can lower LDL cholesterol at the expense of reducing the good HDL cholesterol. High intakes of N6 PUFA can enhance oxidation of fats and produce damaging free radicals, increasing the risk of certain cancers, coronary heart disease and even affect longevity. It has also been reported that oils high in omega 6 can lead to insulin resistance which may lead to obesity, diabetes and interfere with health benefits of omega 3. Dietary intake of N6 PUFA should be adequate but not excessive.

Sources are oils of corn, sunflower, soybean, peanut and safflower.

Omega 3: This health-enhancing class of fat comes from linolenic acid. It is obtained, primarily from cold-water fish and fish oils. It lowers blood pressure and prevents clot formation. Hence, consumption of oily fish is recognised as an important dietary protective measure against heart attacks. The Inuits of the Arctic region have lower incidence of heart disease despite lack of fruits and vegetables in their diet apparently due to their high consumption of oily, cold-water fish. It can also diminish the inflammatory response and ease symptoms of rheumatoid arthritis and Crohn’s disease. They are important for brain health as they exhibit anti-depressant effects. Omega 3 fats also promote cognitive development in newborns and infants and prevent cognitive decline in the elderly.

Sources include sardines, mackerel, salmon, tuna, rapeseed oil, soya oil, mustard oil, flaxseeds, walnuts and pumpkin seeds.

Trans fat: This is man-made fat also known as hydrogenated fat because it is produced by hydrogenation of liquid vegetable oils, converting them into solid fat. It does not turn rancid very easily, hence increases the shelf life of food. It is odourless and has an attractive white colour. It can cause serious damage to health and is implicated in causing cancers, cardiovascular disease, infertility and obesity.

Sources are dalda, margarine, most fried foods, packaged foods such as cookies, chips, biscuits and breads.

WHICH OILS

Edible oils are made up of a mixture of fatty acids — SFA, MUFA, PUFA — and their health properties correspond with the kind and proportion of fatty acids they contain. Oils which contain low amounts of SFA and are rich in MUFA, omega 3 and antioxidants and have a high smoking point are regarded as healthy.

Five best picks:

• Mustard oil
• Groundnut oil
• Canola oil
• Rice bran oil
• Olive oil (the extra virgin variety should not be used for cooking, it can be added after cooking or used as dressings for salads).

How Much?

Fat intake should not exceed 25-30 per cent of your calories:

• Total fat: 50-60 g (visible or invisible)
• Saturated fat: 8-10 per cent of total fat content
• Trans fat: Less than 1 per cent Unsaturated fats
• (MUFA & PUFA): Less than 20 per cent Omega 3: 2 g
• Visible fat (oils): 4-6 tbsp per day.

Fat is an integral part of a balanced, healthy diet and complete abstinence can be damaging to health. Make sure you have healthy fats such as MUFA and Omega 3 because fat is also vital for fitness.