Fats & Cholesterol

What are fats and what do they do?

Fats are a type of nutrient that you get from your diet. It is essential to eat some fats, though it is also harmful to eat too many.

The fats you eat give your body energy that it needs to work properly. During exercise, your body uses calories from carbohydrates you have eaten. But after 20 minutes, exercise then depends on calories from fat to keep you going.

You also need fat to keep your skin and hair healthy. Fat aso helps you absorb vitamins A, D, E, and K, the so-called fat-soluble vitamins. Fat also fills your fat cells and insulates your body to help keep you warm.

The fats your body gets from your food gives your body essential fatty acids called linoleic and linolenic acid. They are called “essential” because your body cannot make them itself, or work without them. Your body needs them for brain development, controlling inflammation, and blood clotting.

Fat has 9 calories per gram, more than 2 times the number of calories in carbohydrates and protein, which each have 4 calories per gram. That is why foods that are high in fat are called “fattening.”

All fats are made up of saturated and unsaturated fatty acids. Fats are called saturated or unsaturated depending on how much of each type of fatty acid they contain.

How much total dietary fat do I need?

  • Consume less than 10% of calories from saturated fats.
  • Replace solid fats with oils whenever possible.
  • Limit foods that contain synthetic sources of trans fatty acids (such as hydrogenated oils), and keep total trans fatty acid consumption as low as possible.
  • Eat fewer than 300 mg of dietary cholesterol per day.
  • Reduce intake of calories from solid fats.
Age Group Total Fat Limits
Children ages 2 to 3 30% to 40% of total calories
Children and adolescents ages 4 to 18 25% to 35% of total calories
Adults, ages 19 and older 20% to 35% of total calories

Types of Fat

Saturated fats raise your LDL (“bad”) cholesterol level. High LDL cholesterol puts you at risk for heart attack, stroke, and other major health problems. You should avoid or limit foods that are high in saturated fats.

  • Keep saturated fats to only 10% of your total daily calories.
  • Foods with a lot of saturated fats are animal products, such as butter, cheese, whole milk, ice cream, cream, and fatty meats.
  • Some vegetable oils — coconut, palm, and palm kernel oils — also contain saturated fats. These fats are solid at room temperature.
  • A diet high in saturated fat increases cholesterol build up in your arteries (blood vessels). Cholesterol is a soft, waxy substance that can cause clogged, or blocked, arteries.

Eating unsaturated fats instead of saturated fats can help lower your LDL cholesterol. Most vegetable oils that are liquid at room temperature have unsaturated fats. There are 2 kinds of unsaturated fats:

  • Mono-unsaturated fats, which include olive and canola oil
  • Polyunsaturated fats, which include safflower, sunflower, corn, and soy oil

Trans fatty acids are unhealthy fats that form when vegetable oil hardens in a process called hydrogenation. Hydrogenated fats, or “trans fats,” are often used to keep some foods fresh for a long time.

Trans fats are also used for cooking in some restaurants. They can raise LDL cholesterol levels in your blood. They can also lower your HDL (“good”) cholesterol levels.

  • Trans-fatty acids are found in fried foods, commercial baked goods (donuts, cookies, and crackers), processed foods, and some margarines.
  • You should avoid foods made with hydrogenated and partially hydrogenated oils (such as hard butter and margarine). They contain high levels of trans-fatty acids.

It is important to read nutrition labels on foods. This will help you know what kinds of fats, and how much, your food contains.

Cholesterol

Cholesterol is a fatty substance that’s found in animal-based foods such as meats, poultry, egg yolks, and whole milks. Do you remember the other type of fat that is found in animal-based products? That’s right — saturated fat.

Polyunsaturated Fats and Monounsaturated Fats

Most of the fat that you eat should come from unsaturated sources: polyunsaturated fats and monounsaturated fats. In general, nuts, vegetable oils, and fish are sources of unsaturated fats. The table below provides examples of specific types of unsaturated fats.

Monounsaturated Fat Sources Omega-6 Polyunsaturated Fat Sources Omega-3 Polyunsaturated Fat Sources
Nuts Vegetable oils Canola oil Olive oil High oleic safflower oil Sunflower oil Avocado Soybean oil Corn oil Safflower oil Soybean oil Canola oil Walnuts Flaxseed Fish: trout, herring, and salmon

Polyunsaturated fats can also be broken down into two types:

  • Omega-6 polyunsaturated fats — these fats provide an essential fatty acid that our bodies need, but can’t make.
  • Omega-3 polyunsaturated fats — these fats also provide an essential fatty acid that our bodies need. In addition, omega-3 fatty acids, particularly from fish sources, may have potential health benefits.

How do I control my polyunsaturated fat and monounsaturated fat intake?

In general, nuts, vegetable oils, and fish are sources of unsaturated fats. The table below provides examples of specific types of unsaturated fats.

Monounsaturated Fat Sources Omega-6 Polyunsaturated Fat Sources Omega-3 Polyunsaturated Fat Sources
Nuts Vegetable oils Canola oil Olive oil High oleic safflower oil Sunflower oil Avocado Soybean oil Corn oil Safflower oil Soybean oil Canola oil Walnuts Flaxseed Fish: trout, herring, and salmon

Below are tips for including appropriate amounts of unsaturated fats in your diet:

  • Replace solid fats used in cooking with liquid oils.
  • Remember any type of fat is high in calories. To avoid additional calories, substitute polyunsaturated and monounsaturated fats for saturated fats and trans fats rather than adding these fats to your diet.
  • Have an ounce of dry-roasted nuts as a snack. Nuts and seeds count as part of your meat and beans “allowance”.

Oils and Cooking

When you cook, solid margarine or butter are not the best choices. Butter is loaded with saturated fat, which can raise your cholesterol. It can also increase your chance of heart disease. Most margarines, on the other hand, have some saturated fat plus trans-fatty acids, which can also be bad for you. Both of these fats have their risks.

If you must use one or the other, some margarines may be better than butter.

What oils to use

As a general rule, try to use extra virgin oils in cooking and avoid margarine and dairy products. Also, low fat options are not very good for you – try to stay away from processed foods. An easy rule of thumb is to only go with foods (in this case oils) with only one ingredient (olive oil, flaxseed oil etc.) These foods are generally not processed.

  • Use olive / canola / sunflower / flaxseed oil instead of butter or margarine.
  • If you want margarine, go with the soft ones (tub or liquid) over harder stick forms.
  • Choose margarines with liquid vegetable oil as the first ingredient (they are ranked after amounts on the ingredients list).

What Not to Use When Cooking

  • Margarine, shortening, and cooking oils that have more than 2 grams of saturated fat per tablespoon (read the nutrition information labels).
  • Hydrogenated and partially hydrogenated fats (read the ingredients labels). These are high in saturated fats and trans-fatty acids.
  • Shortening or other fats made from animal sources, such as lard.

Resources

http://www.nlm.nih.gov/medlineplus/ency/patientinstructions/000104.htm

http://www.nlm.nih.gov/medlineplus/ency/patientinstructions/000095.htm

http://www.cdc.gov/nutrition/everyone/basics/fat/index.html

http://www.cdc.gov/nutrition/everyone/basics/fat/unsaturatedfat.html

http://www.cdc.gov/nutrition/everyone/basics/fat/cholesterol.html

Monounsaturated Fats

Monounsaturated Fats