Past columns have looked at two of the three general important components in our diets.  We have looked at Protein, the building blocks of the body and Carbohydrates, the preferred energy source for the body.  In this column we’ll look at the fat. 

Dietary fat is needed by the body for the proper digestion, absorption and transportation of the fat soluble vitamins: vitamins A,D,E and K are considered the fat soluble vitamins and can be stored in your body.  The ability to be stored may lead to toxicity in extreme cases.  When excess amounts of other vitamins such as Vitamin C are eaten, the kidneys excrete them.  Other than overworking your kidneys, there is no known long-term effect.  Fat also has a vital role in promoting healthy cell function, maintaining healthy skin and hair, maintaining body temperature and storing energy for the body. 

On a food label, total fat refers to the combined fat content of four types of fat in your food.  The four types include saturated, monounsaturated, polyunsaturated and trans fats.  All are fats, but differ slightly in chemical and physical characteristics.   

Saturated fat is found mainly in animal sources.  It is usually a solid at room temperature, although some oils such as coconut and palm oil are also high in saturated fats.  Studies are showing us that a diet that is high in this type of fat is associated with higher cholesterol levels which indicates a higher risk of heart disease.   

Monounsaturated fats are liquid at room temperature.  They can be found in olive, canola and peanut oil.  Research has shown that this is the preferred type of oil that may help lower total blood cholesterol and the LDL (Low Density Lipoproteins) that clog arteries. 

Polyunsaturated fats are also liquid at room temperature.  They can be found in vegetable and seed oils such as safflower and corn oils.  Two types of polyunsaturated fats, omega-6 and omega-3 are called essential fats, which means we must get them from the foods that we eat.  Omega 6 is found in grains, nuts and corn oil.  Omega 3 is found in canola oil, some nuts and fish such as mackerel, salmon and tuna. 

The newest type of fat to receive great public attention is the trans fats.  Tiny amounts may be found in meat and dairy products, but the major amounts come from a commercial process called hydrogenation.  This process converts liquid vegetable oils into sold fats such as stick margarine or vegetable shortening.  Research has shown that trans fats increase the bad cholesterol levels and may lead to an increased risk of heart disease. 

How much fat should we be eating in a day?  The first thing to figure out is how many calories should you be eating in a day.  Most dietary recommendations are based on the number of calories you need to maintain your normal weight.  The number of calories is modified if you intend to lose weight or gain weight. Total fat should represent 20% to 35% of your daily calories.  Saturated fat should be limited to 7% to 10% of your daily calories and transfats should be avoided as much as possible.  The majority of your fat calories should be from the monounsaturated fat group.