Know Your Fats

Contrary to the now-popular concept that less fat intake is better, fats and oils are very important components of a good diet.  Naturally-occurring unprocessed or minimally processed fats and oils have an important role in maintaining good health.  In addition to being a good source of energy, fats help us absorb certain vitamins and nutrients (like vitamins A, D, E, and K). We also need fats for our skin, nails, hair and cell development.  Fats also slow digestion, delaying the onset of hunger and keeping us satiated longer.  Thus, a careful balance of fat in the diet becomes critical for everyone, but even more essential for those trying to lose weight. Too much fat in the diet, the weight shifts in the wrong direction; too little and hunger often creeps up and leads to overeating, especially carbohydrates.

How much fat should we consume? If you are a nomad in the desert, fat is 10% of your caloric intake.  Eskimos consume 50% or more of their calories from fat Both groups have the lowest incident of CHD, clearly indicating that incidence of CHD does not parallel dietary intake of fats, at least for these groups it doesn’t.  If you are not a nomad or Eskimo, the recommended dietary fat intake is between 20% to 35% of daily calories. 

My personal approach to fat is the following: Rather than obsess over the amount of fat consumed, I am very selective about the type of fat I choose to include in my diet, making sure my food includes healthy doses of “good”  fats and minimum amounts of the unhealthy ones. 

Let’s talk about the good and the bad fats.

The two forms of unhealthy fats are saturated and trans fats, the latter also known as partially-hydrogenated oils. These fats—including margarine, vegetable shortening or marbled fat in steak—share a physical trait; they are solid at room temperature.

Saturated fats are associated with high cholesterol levels, especially low-density lipoprotein (LDL), which promote the formation of blockages in the coronary arteries.  Hence the recommendation to cut back on saturated fats.  Not all saturated fats are equally bad for you, however. The saturated fat found in pure chocolate (stearic acid) acts more like unsaturated fats by lowering cholesterol, and coconut oil, a saturated fat, contains lauric acid which has antimicrobial properties that support our immune defenses..

It is not possible to avoid saturated fat entirely, however, because even the healthiest oils contain a small amount of it. 

The other unhealthy fats are the trans fats or partially-hydrogenated oils. I consider trans fats the unhealthiest fats and the ones we should avoid at all costs.  Trans fats are man made fats, a cheap alternative to butter and are used in everything from commercial cookies, packaged snacks, and baked goods and the most widely used fat in restaurant fryers. 

Let’s talk about how these fats came into being and how they ended up being part of our diet.  Traditionally, a cook would choose a fat to prepare a particular dish based on the qualities that fat provided to the food: The special texture and flavor lard gives to a piecrust, the special flavor and creaminess butter imparts to a sauce or to a soup for example.  But experts discouraged the use of these traditional fats and oils, arguing that they contributed to the chronic illness afflicting modern populations. So “man-made” versions __ margarine and vegetable shortening __ were created in laboratories.  These partially- hydrogenated oils replaced the natural fats in the diets of many people, and we ended up with a situation where the natural fats that have been used for centuries are out, and the fabricated fats that should be out are in.

All natural fats, whether saturated or unsaturated are used and needed by the body.  The only fats found in food that are not natural to the human body (i.e. not used or needed by the body) are the trans fats.  Not only do we not need them, but high consumption of trans fats are detrimental to our health in many ways. They
• Lower the good cholesterol (HDL)
• Raise the bad cholesterol (LDL)
• Lower the amount of cream in milk of lactating mothers, thus lowering the quality available to the infant
• Lead to low birth weight in human infants
• Increase blood insulin levels, thus increasing risk for diabetes
• Precipitate childhood asthma

The good fats

Also known as unsaturated fats; these health-promoting fats come mainly from fish and plant sources such as nuts and whole grains.  There are two types, the mono- unsaturated and the polyunsaturated fats.  When you dip your bread in olive oil, you are consuming a monounsaturated fat.  Other good sources of mono-unsaturated fat besides olive oil are canola, safflower and sunflower oils,  avocados and most nuts.

These fats are widely consumed in the Mediterranean countries (think of the Mediterranean diet). The population there enjoys a low rate of heart disease, while consuming a high fat diet, proving again that the type of fats and not the amount plays a key role in promoting health.

There is two widely known polyunsaturated fats, the omega-3 and omega-6 fatty acids. These fats are considered essential fats, which means they are required for normal function of the body, but our body cannot make them, so we must get them from food (our body, as well as plants, manufacture fats).  They are essential for blood clotting, muscle contraction and relaxation, and help keep inflammation at bay. They also help improve the cholesterol profile (lowering LDL and increasing HDL, the good cholesterol).  Omega 3, which comes mostly from fish (fatty fish like salmon, mackerel and sardines are good sources), is also found in flaxseeds and some nuts, including walnuts.  Good sources of omega 6 are vegetable oils, such as safflower, sunflower, walnut oil.

In general, most of us consume enough omega 6 (most oils use for cooking have a high ratio of omega 6), but do not consume enough of omega 3. Hence the need to increase our consumption of fish and nuts.

Enough of facts and figures!  Here are some of my personal preferences and recommendations:

• Fats and oils that should not be used for frying or heated at high temperature are   flaxseed oil, cold pressed olive oil and toasted sesame seed oil. But these are quite appropriate for salad dressing

• For all-purpose frying (I do not do much frying) or cooking at high temperatures, use coconut oil, canola, safflower or sunflower oils.

• Natural fats quite appropriate for cooking include olive oil, canola oil, safflower oil. 

• For baking purposes, especially if baking requires a solid fat, like butter, use coconut oil or coconut butter instead.

• For snacks foods, granola, health bars or making popcorn, use natural cold pressed coconut oil or cold pressed canola oil

• Include a variety of fats and oils in your diet. Do not use only one fat or oil exclusively. Fats differ from each other in health-giving properties, and you need a combination of all.

• Do not save fats and oils that have gone rancid. Throw them away.  To avoid oils going rancid, buy them in smaller containers and use them within a relatively short period (lest than 3 months). Store them in a cool and dry place, not close to the stove. 

• Do not fear all saturated fats. Do include some sources, especially those containing lauric acid, found in anything made from coconut oil.

• Do not consume any product containing partially-hydrogenated oils. Read the labels when buying packaged products.  Better yet, make and package your food at home.