Saturated Fats vs Unsaturated Fats--Polyunsaturated and
Monounsaturated
The Bad Fats
Some fats are bad because they tend to worsen blood cholesterol levels.
Saturated Fats
Saturated fats are mainly animal fats. They are found in meat, seafood, whole-milk dairy products (cheese, milk, and ice cream), poultry skin, and egg yolks. Some plant foods are also high in saturated fats, including coconut and coconut oil, palm oil, and palm kernel oil. Saturated fats raise total blood cholesterol levels more than dietary cholesterol because they tend to boost both good HDL and bad LDL cholesterol. The net effect is negative, meaning it's important to limit saturated fats.
Trans Fats
Trans fatty acids are fats produced by heating liquid vegetable oils in the presence of hydrogen. This process is known as hydrogenation. The more hydrogenated an oil is, the harder it will be at room temperature. For example, a spreadable tub margarine is less hydrogenated and so has fewer trans fats than a stick margarine.
Most of the trans fats in the American diet are found in commercially prepared baked goods, margarines, snack foods, and processed foods. Commercially prepared fried foods, like French fries and onion rings, also contain a good deal of trans fat.
Some fats are good because they can improve blood cholesterol levels.
Unsaturated Fats--Polyunsaturated and Monounsaturated
Unsaturated fats are found in products derived from plant sources, such as vegetable oils, nuts, and seeds. There are two main categories: polyunsaturated fats (which are found in high concentrations in sunflower, corn, and soybean oils) and monounsaturated fats (which are found in high concentrations in canola, peanut, and olive oils). In studies in which polyunsaturated and monounsaturated fats were eaten in place of carbohydrates, these good fats decreased LDL levels and increased HDL levels.
The Bad Fats
Some fats are bad because they tend to worsen blood cholesterol levels.
Saturated Fats
Saturated fats are mainly animal fats. They are found in meat, seafood, whole-milk dairy products (cheese, milk, and ice cream), poultry skin, and egg yolks. Some plant foods are also high in saturated fats, including coconut and coconut oil, palm oil, and palm kernel oil. Saturated fats raise total blood cholesterol levels more than dietary cholesterol because they tend to boost both good HDL and bad LDL cholesterol. The net effect is negative, meaning it's important to limit saturated fats.
Trans Fats
Trans fatty acids are fats produced by heating liquid vegetable oils in the presence of hydrogen. This process is known as hydrogenation. The more hydrogenated an oil is, the harder it will be at room temperature. For example, a spreadable tub margarine is less hydrogenated and so has fewer trans fats than a stick margarine.
Most of the trans fats in the American diet are found in commercially prepared baked goods, margarines, snack foods, and processed foods. Commercially prepared fried foods, like French fries and onion rings, also contain a good deal of trans fat.
Trans fats are even worse for
cholesterol levels than saturated fats because they raise bad LDL and lower
good HDL. While you should limit your intake of saturated fats, it is important
to eliminate trans fats from partially hydrogenated oils from your diet.
The Good FatsSome fats are good because they can improve blood cholesterol levels.
Unsaturated Fats--Polyunsaturated and Monounsaturated
Unsaturated fats are found in products derived from plant sources, such as vegetable oils, nuts, and seeds. There are two main categories: polyunsaturated fats (which are found in high concentrations in sunflower, corn, and soybean oils) and monounsaturated fats (which are found in high concentrations in canola, peanut, and olive oils). In studies in which polyunsaturated and monounsaturated fats were eaten in place of carbohydrates, these good fats decreased LDL levels and increased HDL levels.
Percentage of Specific Types of Fat in Common Oils and Fats*
|
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Oils
|
Saturated
|
Mono-unsaturated
|
Poly-unsaturated
|
Trans
|
Canola
|
7
|
58
|
29
|
0
|
Safflower
|
9
|
12
|
74
|
0
|
Sunflower
|
10
|
20
|
66
|
0
|
Corn
|
13
|
24
|
60
|
0
|
Olive
|
13
|
72
|
8
|
0
|
Soybean
|
16
|
44
|
37
|
0
|
Peanut
|
17
|
49
|
32
|
0
|
Palm
|
50
|
37
|
10
|
0
|
Coconut
|
87
|
6
|
2
|
0
|
Cooking
Fats
|
||||
Shortening
|
22
|
29
|
29
|
18
|
Lard
|
39
|
44
|
11
|
1
|
Butter
|
60
|
26
|
5
|
5
|
Margarine/Spreads
|
||||
70%
Soybean Oil, Stick
|
18
|
2
|
29
|
23
|
67%
Corn & Soybean Oil Spread, Tub
|
16
|
27
|
44
|
11
|
48%
Soybean Oil Spread, Tub
|
17
|
24
|
49
|
8
|
60%
Sunflower, Soybean, and Canola Oil Spread, Tub
|
18
|
22
|
54
|
5
|
*Values
expressed as percent of total fat; data are from analyses at Harvard School
of Public Health Lipid Laboratory and U.S.D.A. publications.
|
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