Linda Boeckner, Extension
Nutrition Specialist
Nutrition professionals encourage adults and
children above age two to select diets low in total fat, saturated fat and
cholesterol. To reach recommended levels of 30 percent of calories from total
fat and 10 percent of calories from saturated fats, many Americans will have to
cut out one-fifth of their current fat intake.
Methods to reduce total fat intakes include
low fat cookery such as boiling, broiling, steaming, stewing, baking and
roasting. Consumers may also trim visible fat from meat and poultry products
and limit fat spreads, dressings, gravies and other sauces. Another way to
achieve lower total fat intake is to take stock of fat-rich desserts and snack
foods. Substitute fruits and vegetables for rich desserts and oily snacks
instead.
When you reduce total fat,
you will likely reduce the saturated fat portion as well. To be sure, pay
attention to whether the foods you eat have more saturated, polyunsaturated, or
monounsaturated fatty acids in them. Saturated fatty acids raise blood
cholesterol levels, one of the major risk factors for heart disease.
Polyunsaturated and monounsaturated fatty acids lower blood cholesterol levels.
Some evidence suggests that not all
saturated fatty acids produce a blood cholesterol raising effect. Stearic acid
is an example of such a saturated fatty acid. As for fats in food, however,
consumers should be aware that more than one type of saturated fatty acid will
be present. Foods that are rich in stearic acid will also likely contain
saturated fatty acids that do raise blood cholesterol levels. Until further
study shows otherwise, the general recommendation still stands to limit
saturated fats in the diet.
Food fats are a combination
of saturated, monounsaturated and polyunsaturated fatty acids. Nutritionists
often classify fats according to the type of fatty acid present in the greatest
amount. Thus, some fats like beef tallow, butter, coconut, and palm kernel oils
are known as saturated fats. Products such as corn, soybean, sunflower, and
safflower oils are called polyunsaturated fats. Canola, olive and peanut oils
are known for their monounsaturated fatty acid content.
In general, saturated fats are solid at room
temperature. They are more stable than unsaturated fats and have less chance of
breaking down or becoming rancid over time. That is why saturated fats are
often the candidate of choice for commercial frying.
Unsaturated fats, both polyunsaturated and
monounsaturated, are liquid at room temperature. We typically think of vegetable
oils as good sources of polyunsaturated and monounsaturated fats, and low in
saturated fats. The exceptions are coconut and palm kernel oils. They contain
more than 80 percent saturated fatty acids by weight. Nutritionists recommend
that both polyunsaturated and monounsaturated fats be kept at approximately 10
percent of calories.
Vegetable shortenings are a blend of many
types of vegetable oils. The oil becomes solid or firm through the process of
hydrogenation. The result is a product that has a lower polyunsaturated fatty
acid content and a higher saturated fatty acid content than liquid vegetable
oils. Hydrogenation also forms monounsaturated fats that have a different
physical arrangement. These trans monounsaturated fatty acids are similar in
stability to saturated fatty acids. Research shows their effect on blood
cholesterol levels is variable. From ten percent to almost one-third of
margarines and hydrogenated vegetable shortenings are trans fatty acids.
Vegetable shortenings are less desirable than
vegetable oils as a food fat because of their fatty acid makeup. Similarly,
margarines are also blends of liquid vegetable oils and partially hydrogenated
vegetable oils. To keep saturated fatty acid content to a minimum use margarine
that lists liquid vegetable oil first in its ingredient label. In general
softer margarines are a better choice than those which are harder.
Fish oils garnered much
attention during the 1980s. At first glance they appeared to reduce heart
disease risk by lowering fat levels in the blood. Fish oils contain highly
unsaturated fatty acids. They are known as omega-3 fatty acids.
In studies about the relationship of fish
oils and coronary heart disease risk, researchers noted some unfavorable
effects. One of the predominant effects was a delayed blood clotting time.
Researchers also found that high intakes of omega-3 fatty acids did not always
reduce blood cholesterol levels.
It is premature to say that individuals
would benefit by adding fish oil capsules to their diets. In fact, there are
some potential hazards. Instead, consumers may choose to include omega-3 fats
by selecting appropriate food sources. Cold, deep water fish such as salmon,
mackerel, tuna, herring, and sablefish; and cold, fresh water fish such as
trout are possible choices.
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Table 1. Recommended Caps on Total and Saturated
Fat Intake at Various Caloric Levels. |
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Total Calories |
Total Fat (g) |
Saturated Fat (g) |
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|
1200 |
40 |
13 |
|
1500 |
50 |
17 |
|
1800 |
60 |
20 |
|
2100 |
70 |
23 |
|
2400 |
80 |
27 |
|
2700 |
90 |
30 |
|
3000 |
100 |
33 |
|
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Reading labels is important.
To tackle saturated fats in your diet, identify and limit using products that show
a higher saturated fatty acid content. Words on an ingredient label that
indicate a higher saturated fat content are: hydrogenated vegetable fat,
partially hydrogenated vegetable oil, lard, coconut oil, and palm kernel oil.
Many of the commercially made crackers, cookies, baking mixes, breakfast
cereals and breakfast bars contain these ingredients. Read the nutrition label
to find the product with the least grams of saturated fat.
The grams of total and saturated fats to
meet fat guidelines at various caloric levels are shown in Table 1. Table 2
provides a look at the saturated, monounsaturated, and polyunsaturated fatty
acid and cholesterol contents of some common fats. The fats are in order from
the lowest to the highest saturated fatty acid content.
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Table 2. Fatty Acid and
Cholesterol Composition of Some Common Fats |
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Saturated |
Monounsaturated |
Polyunsaturated |
Cholesterol |
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Canola Oil |
1.0 |
8.2 |
4.1 |
0 |
|
Safflower Oil |
1.2 |
1.6 |
10.1 |
0 |
|
Sunflower Oil |
1.4 |
2.7 |
8.9 |
0 |
|
Corn Oil |
1.l7 |
3.3 |
8.0 |
0 |
|
Olive Oil |
1.8 |
9.9 |
1.1 |
0 |
|
Sesame Oil |
1.9 |
5.4 |
5.7 |
0 |
|
Soybean Oil |
2.0 |
3.2 |
7.9 |
0 |
|
Peanut Oil |
2.3 |
6.2 |
4.3 |
0 |
|
Vegetable Shortening |
3.2 |
5.7 |
3.3 |
0 |
|
Chicken Fat |
3.8 |
5.7 |
2.7 |
11 |
|
Lard |
5.0 |
5.8 |
1.4 |
12 |
|
Beef Tallow |
6.4 |
5.3 |
0.5 |
14 |
|
Palm Oil |
6.7 |
5.0 |
1.3 |
0 |
|
Butter |
7.1 |
3.4 |
0.6 |
31 |
|
Palm Kernel Oil |
11.1 |
1.5 |
0.2 |
0 |
|
Coconut Oil |
11.8 |
0.8 |
0.2 |
0 |