Fitness articles

Facts About Fat: Time for an Oil Change

28/01/2011by in ,

Fat Functions

Not only does fat make food tastier, it is also an essential component of a healthful diet. Many are often afraid to eat any fat and don’t realise that fat provides essential nutrients we simply cannot live without.

1. Fat helps transport and absorb carotenoids (phytochemicals found in red and orange fruits and vegetables) and the fat soluble vitamins A, D, E & K.
2. It also acts as a thermal blanket, defending the body against heat loss and as a protective cushion for tissues and organs
3. Fat helps the body produce hormones and prostaglandins (hormone – like substances) that regulate bodily processes.
4. As a component of every cell membrane in our bodies, fat is instrumental in protecting against foreign invaders, while allowing nutrients to enter and waste products to exit properly

Fat Types

Fats are basically triglycerides, which are made up of 3 fatty acids attached to a glycerol molecule. Fatty acids are building blocks that give fat its most basic personality, which can either be saturated or unsaturated.

The more saturated a fat is, the more solid its form is. Unsaturated fats can be classified one step further, as either monounsaturated or polyunsaturated.

While all dietary fats and oils are a mixture of saturated, monounsaturated and polyunsaturated fat, they are classified based on the particular fatty acid that is found in the highest proportion. For example Olive Oil contains approx. 1g of polyunsaturated fat, 2g of saturated fat and 11g of monounsaturated fat, it is classified as a monounsaturated fat.

Saturated Fats

Are derived primarily from animal sources. As a rule they are solid at room temp., with 2 exceptions, coconut oil and palm oil. Saturated fats elevate triglyceride and cholesterol levels, both of which are strongly linked to an increased risk of heart disease and certain cancers. Saturated fats are present in red meats, lard, whole milk diary products and hydrogenated vegetable oils.

Monounsaturated Fats

Are derived from plant sources and are liquid at room temp. Food sources include: olive, canola, almond, cashew, hazelnut, macadamia, peanut and pecan oils. Experts recommend olive oil over most other oils, with canola being a great runner up. Several studies have demonstrated olive oil decrease the “bad” LDL cholesterol while maintaining the “good” HDL cholesterol.

Polyunsaturated Fats

Are derived primarily from plant sources and are liquid at room temp. Food sources include: corn, cottonseed, flaxseed, safflower, sunflower, soybean, walnut and sesame oils. When eaten in place of saturated fats, polyunsaturated fats appear to decrease blood cholesterol levels. However, their benefit on heart health is debatable since they seem to lower not only the undesirable LDL cholesterol but also the beneficial HDL cholesterol.

Essential Fatty Acids (EFA’s)

Some polyunsaturated fats are considered “essential”, meaning they must be derived from food because the human body cannot manufacture them. The 2 major classes are Omega 6 (linoleic acid) and Omega 3 (linolenic acid)

Omega 6: are easily obtained in the diet from nuts, wheat germ and vegetable oils, such as corn, safflower, sesame, soybean and sunflower. Some research suggests that consuming too many omega 6 EFA’s may increase the risk of some cancers.

Omega 3: These health-protective EFA’s are found in plants and some types of fish. The richest food sources are deep-coloured, cold water fish – especially salmon, mackerel, herring, halibut, tuna and sardines. The richest plant sources are flaxseeds, hemp seeds, walnuts and their oils.

The beneficial effects on bodily functions: they inhibit the formation of blood clots, reduce the risk of heart attacks, improve immune function, promote eye and brain development and have an anti-inflammatory effect.

Hyrdogenated Oils & Trans Fatty Acids

Hydrogenation is the process by which liquid vegetable oil is transformed into solid margarine. Using extreme heat, unsaturated vegetable oils are “pumped up” with hydrogen and, in effect, turned into saturated fats. This processing bends the chemical structure of the fatty acids into unnatural shapes, producing trans fatty acids or trans fats. Research now indicates that artificially produced trans fats may be more harmful to our health than saturated fats.

In addition to margarine, sources of trans fats include shortening, deep-fried foods, breads, crackers, cookies, baked goods, candy, cereals, snack foods, spreads and numerous other processed and prepared foods.

To avoid buying products that contain trans fat, check the label for the terms “hydrogenated oils” or “partially hydrogenated oils”.

Conjugated Linoleic Acid

The most recent fatty acid to make front page news. It is a fatty acid found predominantly in beef, lamb and diary products, especially cheese. CLA seems to reduce cancer risk, enhance immune response and increase muscle mass.

Olestra

This is the stealth missile of fat molecules; it passes through the gastrointestinal tract without being digested or absorbed. As far as the human body is concerned, olestra is fat-free fat. Made from a combination of soy bean oil and table sugar, it makes the oil too “fat” for digestive enzymes to break it down. Hence olestra passes through he body without becoming a source of calories. On the other hand there have been reports that it can trigger intestinal cramping, flatulence and loose bowels. It also reported that it keeps the body from absorbing some carotenoids, nutrients that may lower the risk of cancer and heart disease.

Fats and Dairy

In a Standard Western diet, the biggest proportion of fat usually comes from dairy. Milk, cream, cheese, butter, and fermented milk products (including yoghurt), ice cream and the many processed dairy products on the supermarket shelves are the culprits. When you look into these products for their fat percentage by calories, butter is the worst , as it is 100% fat. Cream is 89% fat, cheeses average about 74 % fat and whole milk is about 49% fat.

Saturated fats make up about 60% of the fat content in the above mentioned dairy products. Despite a wholesome image and clever marketing, whole milk and fatty dairy products are some of the most unhealthy foods in our diet.

Fat and Protein Content

To see the fat and protein content of different cuts of meat and fish, please click the following link: Fat and Protein Content

The Low Fat Debate

Whatever your dietary profile, low-fat food is vastly over-rated. Most low-fat products are nutritionally inferior to their less-processed, full-fat counterparts; something has to replace fat and usually it’s sugar, corn syrup, sweeteners, or chemicals.

If you think that switching to low-fat food alternatives will fix your weight problem, think again. All that low-fat food has done is lull us into believing that we can eat more of it, according to a new Cornell University study.

The Cornell study zealously traced every calorie that we consume in theatres, holiday receptions and in the home; and what they found was that people eat 28 percent more food (up to 45 percent more for the obese) when they know that what they are consuming is low-fat. "People don’t realize that low-fat foods are not always low-calorie foods," lamented lead researcher Brian Wansink.

Identifying and eating low-fat foods may provide some reassurance, but in reality, fat is often substituted with increased levels of sugar. This means that consumers believe that a low-fat alternative has up to 40 percent fewer calories than regular brands, when the actual figure is more likely to be only around 11 percent, say the researchers.

The study also showed that a person’s perception of what they thought amounted to a regular portion of food was often skewed when faced with low-fat alternatives. "People believe they will feel less guilty eating the low-fat foods, so they tend to overindulge, said study co-author, Pierre Chandon.

Additionally, the study subjects would eat foods they didn’t normally like as long as they were labelled "low-fat." For this reason, and the fact that people tend to overindulge when eating low-fat foods, Wansink suggests a far more practical tactic for the weight-conscious. "Stick with the regular version, but eat a little bit less. It’s better for both your diet and your taste buds."

Source: Cornell University Food Lab