The Fats of Life
-
June 15, 2005
The Fats Of Life
A fat-free life is probably the ideal - or so we think. But not all fats are bad and some fats are, in fact, necessary as they do the body good. So how do you know what kind to take? Elaine Young goes on a fat-finding mission.
Fat is what makes those buttons pop, seams strain and zippers stop halfway up, and what every slimming centre and diet plan promises to strip you of.
But in fact, you should not be trying to eliminate all the fat from your diet. You need fat to function.
'Fat is an important source of fuel for the body and also an essential nutrient required by the body. It is not only a concentrated source of energy, but it also helps our body to absorb, transport and store fat-soluble vitamins A, D, E and K,' says Ms Verena Tan, dietitian at Tan Tock Seng Hospital.
Health Promotion Board (HPB) nutritionists agree that fat has many important roles in our body. We need essential fats, such as omega-3 fatty acids - which are found mainly in oily fish, such as sardines, tuna, salmon or mackerel - for healthy skin and eyes.
People with a higher intake of omega-3 fatty acids are also known to have a lower risk of heart disease and stroke.
Of course, what we don't need is excess fat in our bodies. Diets high in total fat are associated with higher obesity rates and an increased risk of heart disease.
So what fat is good for you and what fat is bad for you?
Fat can be classed into two groups: saturated and unsaturated. Saturated fat is considered 'bad' fat. Unsaturated fat, which includes monounsaturated and polyunsaturated fats, is considered 'good'.
The trans fats you hear so much about these days are considered bad because they have a similar effect to saturated fat, and raise cholesterol levels.
The HPB recommends that fat should constitute 25-30 per cent of dietary energy. Of this, less than 10 per cent should come from saturated fat, less than 1 per cent from trans fat, up to 10 per cent from polyunsaturated fat and the remaining from monounsaturated fat.
Based on a 2,100kcal diet, this translates to a maximum of 70g of fat, of which less than 21g should be saturated fat, no more than 2g trans fat, up to 21g polyunsaturated fat and up to 26g monounsaturated fat.
To put that into perspective, Ms Tan says, one medium-size packet of commercially prepared fries can contain almost 2g of trans fat, the daily limit.
For some local food, the saturated fat content may be high but trans fat negligible.
This is the case with a bowl of laksa (including all the gravy), which contains around 32g of fat, including 25g of saturated fat, but barely any trans fat. If you leave out half the gravy, though, you bring the total fat down to 16g and the saturated down to 13g.
However, all fats, whether 'good' or 'bad', still contain nine calories per gram.
'Both mono- and polyunsaturated fat lower blood cholesterol when they replace saturated fat in the diet. However, though monounsaturated and polyunsaturated fat have health benefits, they should still be consumed in moderation as part of a healthy balanced diet,' advises Ms Tan.
If you eat too much 'good' fat, there is a risk of excessive calorie intake and weight gain. As obesity increases your risk of developing chronic diseases, this will effectively negate the beneficial effects of eating good fats. -
SATURATED FAT
A saturated fat has the maximum possible number of hydrogen atoms attached to every carbon atom. It is, therefore, 'saturated' with hydrogen atoms, and all the carbons are attached to each other with single bonds.
The fat found in animal-derived foods is mostly saturated and is solid at room temperature.
Saturated fat is the main dietary cause of high cholesterol in the blood. The American Heart Association advises that your saturated fat intake every day should make up only 7-10 per cent of total calories, because this is the fat that raises your cholesterol and increases your risk of coronary heart disease.
You'll find saturated fat in beef, veal, lamb, pork, lard, poultry fat, butter, bread, milk, cheese and other products made from whole milk. This fat can be found in plants too, including coconut oil, palm oil, palm kernel oil and cocoa butter. -
UNSATURATED FAT
The fat found in plant foods is mostly unsaturated fat, which is usually liquid at room temperature.
This type of fat has one or more pairs of hydrogen atoms in the middle of a chain missing.
This causes two carbon atoms to be connected by a double bond rather than a single bond. As the chain has fewer than the maximum number of hydrogen atoms, it is said to be 'unsaturated'.
Monounsaturated fat, then, has one double bond and polyunsaturated fat has more than one double bond.
Monounsaturated fats and polyunsaturated fats are found mainly in oils from plants. Canola, olive and peanut oils and avocados all contain monounsaturated fats.
Sesame seeds, sunflower seeds, corn, soya beans, salmon and fish oil all contain polyunsaturated fats. -
FATTY ACIDS
The absolutely essential fats for you are in the polyunsaturated camp: linoleic acid, or omega-6, and alpha-linolenic acid, or omega-3.
You need these in roughly the same amount, so if up to 10 per cent of your daily fat intake should come from this group, as recommended by HPB, that's 5 per cent of each omega.
The top of the omega-6 tree sits linoleic acid, which is converted into gamma-linolenic acid (GLA) by the body. The richest sources of this are found in evening primrose oil and borage oil.
This fat is used to build the brain and also, by conversion to a hormone-like substance called prostaglandins, contributes to keeping the blood thin, which prevents clots and blockages, lowers blood pressure, improves immune function and maintains the water balance in the body.
Omega-6 fats are also found in hemp, pumpkin, sunflower, sesame, soya bean and wheat germ oil.
British-based nutritionist Patrick Holford recommends one or two tablespoons of seeds from this group every day, if this is your only source of essential fats.
Omega-3 fats EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) also make prostaglanins, which have similar brain-boosting and anti-inflammatory benefits to the omega-6 fats.
They are found in mackerel, herring, salmon, tuna, sardines, swordfish and white fish, as well as the flax, pumpkin and walnut seeds.
Here, Mr Holford recommends eating 100g of oily fish twice a week. -
TRANS FAT
Trans fat is a curiosity, because technically it is polyunsaturated, which should make it good. But in fact it blocks the body's ability to use polyunsaturated oils.
Trans fat is a hard fat and is used in cakes, pastries, biscuits and most margarines.
Like the saturated group before, these also increase LDL (bad cholesterol) and lower HDL (good cholesterol) and so increase the risk of heart disease.
And trans fat is not a new concern. In the 1980s, a report in the United States found that women with the highest intake of trans fatty acids had a 27 per cent greater risk of heart disease than women with the lowest intake.
According to the HPB, some studies have also reported that when compared with saturated fat, trans fat might put you at a greater risk of heart disease.
Many people are worried about margarine as it contains trans fat, so does that mean that butter is a healthier choice?
Not necessarily, according to dietitian Ms Tan, who says 'a teaspoonful (5g) of soft margarine provides less than 1g of trans fat, which is less than half the amount of trans fat in hard margarine. The total amount of trans fat and saturated fat in soft margarine is less than half that in butter. Hence, soft margarine is still a healthier choice than butter'. -
Do u get the title rite?
-
OILS
Oils are a mixture of saturated, monounsaturated and polyunsaturated fat. Each type of oil contains these to varying degrees.
Cannot distribute vertically Whether a type of oil is considered 'good' or 'bad' depends on how much 'good' or 'bad' fat it contains.
Blended vegetable oil, palm oil and coconut oil are vegetable oils, but they are high in saturated fat. Blended vegetable oil has on average 41 per cent saturated fat, while palm oil is 45 per cent saturated fat and coconut oil is a whopping 85 per cent saturated fat.
Oils that are high in polyunsaturated fat include sunflower, corn, sesame and soya bean oil, while peanut, olive, and canola oils are high in monounsaturated fat. All these oils generally contain less than 20 per cent saturated fat.
Although coconut oil is a saturated fat, Mr Holford says that it is a good cooking choice because the body metabolises coconut butter, oil or milk quickly, converting the fats to energy rather than storing them as fat. As a result, this fat does not elevate bad cholesterol and is rich in lauric acid.
In the body, lauric acid converts into monolaurin, a compound which fights viruses. It is also found in Breast milk. -
Good, Bad and Oily
Blended vegetable, palm and coconut oil are vegetable oils but they are high in 'bad' saturated fat.
Oils that are high in 'good' polyunsaturated fat include sunflower, corn, sesame and soybean oil, while peanut, olive and canola oils are high in monounsaturated fat. All these oils generally contain less than 20 per cent saturated fat.
However, although polyunsaturated fats are health-giving in seeds and fish oils, nutritionist Patrick Holford recommends that you don't use polyunsaturated fats for high-temperature cooking - such as frying, as they are prone to damage and generate oxidising free radicals, which attack your immune system. He suggests using monounsaturated, like olive oil, instead because these types don't generate free radicals. -
How to keep intake low
The nutritionists at the Health Promotion Board and Tan Tock Seng Hospital suggest ways to keep your consumption of saturated fats and trans fat low and still have a nutritionally adequate diet:
When eating out, choose dishes cooked without coconut cream or coconut milk; choose plain rice over flavoured rice (for example, chicken rice, nasi lemak, nasi briyani).
Read the food labels and limit purchases of products containing ingredients such as 'hydrogenated fat', 'shortening' and 'vegetable oil'. Shortening is a solid fat made from vegetable oil that is flavourless and used as a subsitute for other fats in baking and cooking.
When cooking at home, choose oils that are high in polyunsaturated or monounsaturated fat.
Oils high in polyunsaturated fat include sunflower and soya bean oil, while canola and olive oil are high in monounsaturated fat.
Prepare foods using low-fat cooking methods such as steaming, grilling and broiling.
Remove all visible fats from meat. Use lean cuts of meat and poultry.
Fish, especially deep-sea fish such as salmon, mackerel, sardines and tuna are rich in omega-3 fat, a type of polyunsaturated fat.
Limit deep-frying to no more than twice a week.
Use lower-fat dairy products such as skimmed milk, non-fat/low-fat yogurts and reduced-fat cheese
Eat fewer foods made with coconut milk, which contains 25 per cent saturated fat.
Eat less fast food, pastries, cakes and biscuits. These are the main sources of trans fat in our diet.
Make sparing use of spreads such as peanut butter, hard margarine, butter and kaya. These tend to be high in both trans fat and saturated fat.
Use low-fat milk instead of non-dairy creamer in beverages. A main ingredient in non-dairy creamer is vegetable shortening.
Choose products labelled with the Healthier Choice Symbol. These products are lower in saturated fat. -
yup puuurrrfect~Originally posted by SBS9828X:Do u get the title rite?
happie reading
-
feel fat reading all these
-
i'm fat
-
ur TAFOriginally posted by kops21:i'm fat -
YESOriginally posted by BabyLover:ur TAF -
if u r fat, then i m chronically obeseOriginally posted by kops21:i'm fat -
Time to go chiong gym and swimming pool
-
Originally posted by rainee:Time to go chiong gym and swimming pool
like abv said try to keep the oil n fats intake low lor