An Introduction to Fats

Short Chain Fatty Acids

Remember reading about fiber in the carbohydrate lesson? Your body can't digest fiber, which is good for adding bulk to the stool, but fiber has one other important function. The friendly bacteria that live in your colon ferment the fiber and produce short chain fatty acids. Short chain fatty acids have only two to four carbons in their chains. These short chain fatty acids are easily absorbed into the walls of the colon and help to keep the colon tissue healthy and can reduce inflammation. This is important for people with inflammatory bowel diseases who may benefit from adding fiber to their diet to make sure they have enough of these short chain fatty acids in the colon. These fatty acids may also help to prevent colon cancer.

Choosing Healthy Fats

Getting enough fat in the diet is usually not much of a problem, however many people choose too many of the bad saturated and trans fats. You may need to choose more foods with the omega-3 essential fatty acids as well, although most people get enough of the omega-6 essential fatty acids from vegetable oils.

The types of fat you eat have such a big impact on your health. Choose foods with healthy fats and use the right oils and fats for cooking. Here are some healthy and delicious ideas for getting healthy fats:

• Eat fish or seafood at least three times per week. The fish should not be fried in batter.
• Eat nuts and seeds as snacks. Almonds, walnuts, sunflower seeds and pumpkin seeds are good choices.
• Choose canola oil, olive oil and soy bean oil for cooking.
• Flax seed oil is high in omega-3 essential fatty acids, but it is not good for cooking. Use flax seed oil cold.

Here are some common foods and their fat content:

• One cup low fat milk - 2.4 grams total fat, 1.5 grams saturated fat, 12 mg cholesterol
• Three ounces canned tuna - 0.7 grams total fat, 0.2 grams saturated fat, 0.24 g omega-3 EFA, 26 mg cholesterol
• One batter-fried chicken leg - 25.5 grams total fat, 6.8 grams saturated fat, 142 grams cholesterol
• One ounce (14 halves) walnuts - 18.5 grams total fat, 2.5 grams monounsaturated fat, 13.4 grams polyunsaturated fat
• One half cup navy beans - 0.56 grams total fat, 0.3 grams polyunsaturated fat, 0 cholesterol
• One broiled sirloin steak - 33 grams total fat, 12.8 grams saturated fat, 248 mg cholesterol
• One half cup avocado cubes - 11 grams total fat, 1.6 grams saturated fat, 7.3 grams monounsaturated fat, 0 mg cholesterol
• One half cup roasted chicken breast meat - 2.5 grams total fat, 0.71 grams saturated fat, 60 mg cholesterol
• Three ounce salmon fillet - 10.5 grams total fat, 2.1 grams saturated fat, 1.8 grams omega-3 EFA, 54 mg cholesterol
• One teaspoon flax seeds - 4.3 grams total fat, 2.9 grams omega-3 EFA, 0 mg cholesterol
• One three ounce pork chop - 11.1 grams total fat, 4.1 grams saturated fat, 70 mg cholesterol
• One piece of apple pie - 19.4 grams total fat, 4.7 grams saturated fat, 5.0 grams polyunsaturated fat, 0 mg cholesterol

Source: USDA National Nutrient Database

This Week’s Assignment

Many people do not get enough omega-3 essential fatty acids from the foods they eat. This week your assignment is to choose a food with some omega-3 essential fatty acids every day. Some examples include a serving of fish, flax seeds, walnuts, pumpkin seeds, canola oil or "omega eggs."

This Week’s Quiz

You can test your knowledge of fats with this quiz: Quiz Three - Fats This is lesson three of the About Nutrition Basic Nutrition Course. You may sign up for the whole e-course at About Nutrition

_Sources:

USDA. "National Nutrient Database for Standard Reference." Release 20. September 2007.

Gropper SS, Smith JL, Groff JL. "Advanced Nutrition and Human Metabolism." Fourth Edition. Belmont, CA. Wadsworth Pub Co. 2005.

Food and Nutrition Board, Institute of Medicine, National Academies. "Dietary Reference Intakes (DRIs): Recommended Intakes for Individuals, Macronutrients." Published 2004.

Harvard School of Public Health. "Fats & Cholesterol." 2007.